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Joun WT, Lee KK. Experimental study for visualizing CO 2-dissolved water plume migration under hydraulic gradient conditions and implication for field monitoring data. J Environ Manage 2024; 357:120814. [PMID: 38581896 DOI: 10.1016/j.jenvman.2024.120814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 03/03/2024] [Accepted: 04/01/2024] [Indexed: 04/08/2024]
Abstract
Investigating the possible direction of a CO2-dissolved water plume migration near the potential CO2 leakage area is a significant task because it helps estimate the spatial and temporal monitoring scale to detect the signal of released CO2 from the storage. Accordingly, the Korea CO2 Storage Environmental Management (K-COSEM) research center tried to develop an intensive monitoring system and applied it to the artificial CO2 release test in the actual field. Monitoring data from the field tests depicted the horizontal movement of the CO2-dissolved water plume along the direction of the groundwater flow. However, it remains unclear how the CO2-dissolved water plume migrates vertically and how gas accumulation occurs near the capillary zone. The present study simulated the CO2 release test with a visual expression method utilizing a Hele-Shaw cell with hydraulic gradient conditions (i = 0, 0.1, and 0.01) and tried to estimate the significant influences on a diffusive-advective transport of the dissolved gas plume with the shallow aquifer condition. The visualization experiment results were intuitively verified to determine whether the theoretical principles of action related to plume flow applied in this context. The results suggest that a CO2-dissolved water plume is distributed by hydraulic gradients and density-driven CO2 convective flow. The plume shape, center, and area were analyzed using an image analyzer program; the results demonstrated that the plume characteristic evolved depending on the significant effects on the plume. When the plume was mainly affected by the hydraulic gradient, it rapidly moved from the injection point to the last boundary; in contrast, when it was influenced primarily by density-driven CO2 convective flow, it flowed diagonally downward in the shape of varied branches. The numerical model calculated the migration of the CO2-dissolved water plume affected by both factors. The laboratory experiment and numerical simulation results suggest that the migration of a CO2-dissolved water plume may be affected by the hydraulic gradient and density-driven CO2 convective transport. As such, these factors should be considered when designing and analyzing CO2 monitoring signals to detect CO2 leaks from shallow aquifer systems.
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Affiliation(s)
- Won-Tak Joun
- Disposal Performance Demonstration R&D Division, Korea Atomic Energy Research Institute, Daejeon, South Korea.
| | - Kang-Kun Lee
- School of Earth and Environmental Science, Seoul National University, Seoul, South Korea.
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2
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Kaown D, Lee E, Koh DC, Mayer B, Mahlknecht J, Park DK, Yoon YY, Kim RH, Lee KK. The effects of heavy rain on the fate of urban and agricultural pollutants in the riverside area around weirs using multi-isotope, microbial data and numerical simulation. Sci Total Environ 2024; 912:169422. [PMID: 38135072 DOI: 10.1016/j.scitotenv.2023.169422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/23/2023] [Accepted: 12/14/2023] [Indexed: 12/24/2023]
Abstract
The increase in extreme heavy rain due to climate change is a critical factor in the fate of urban and agricultural pollutants in aquatic system. Nutrients, including NO3- and PO43-, are transported with surface and seepage waters into rivers, lakes and aquifers and can eventually lead to algal blooms. δ15N-NO3-, δ18O-NO3-, and δ11B combined with hydrogeochemical and microbial data for groundwater and surface water samples were interpreted to evaluate the fate of nutrients in a riverside area around weirs in Daegu, South Korea. Most of the ions showed similar concentrations in the groundwater samples before and after heavy rain while concentrations of major ions in surface water samples were diluted after heavy rain. However, Si, PO43-, Zn, Ce, La, Pb, Cu and a number of waterborne pathogens increased in surface water after heavy rain. The interpretation of δ11B, δ15N-NO3-, and δ18O-NO3- values using a Bayesian mixing model revealed that sewage and synthetic fertilizers were the main sources of contaminants in the groundwater and surface water samples. δ18O and SiO2 interpreted using the Bayesian mixing model indicated that the groundwater component in the surface water increased from 4.4 % to 17.9 % during the wet season. This is consistent with numerical simulation results indicating that the direct surface runoff and the groundwater baseflow contributions to the river system had also increased 6.4 times during the wet season. The increase in proteobacteria and decrease of actinobacteria in the surface water samples after heavy rain were also consistent with an increase of surface runoff and an increased groundwater component in the surface water. This study suggests that source apportionment based on chemical and multi-isotope data combined with numerical modeling approaches can be useful for identifying main hydrological and geochemical processes in riverside areas around weirs and can inform suggestions of effective methods for water quality management.
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Affiliation(s)
- Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Eunhee Lee
- Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, Republic of Korea
| | - Dong-Chan Koh
- Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, Republic of Korea
| | - Bernhard Mayer
- Department of Earth, Energy and Environment, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Jürgen Mahlknecht
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Campus Monterey, Eugenio Garza Sada 2501, Monterrey 64149, Nuevo León, Mexico
| | - Dong Kyu Park
- Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, Republic of Korea
| | - Yoon-Yeol Yoon
- Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, Republic of Korea
| | | | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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3
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Ju Y, Baik MH, Lee SY, Lee KK, Kaown D, Shin D, Ryu JH. Identifying the origin and fate of dissolved U in the Boeun aquifer based on microbial signatures and C, O, Fe, S, and U isotopes. J Hazard Mater 2023; 459:132051. [PMID: 37467612 DOI: 10.1016/j.jhazmat.2023.132051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/12/2023] [Accepted: 07/10/2023] [Indexed: 07/21/2023]
Abstract
The uranium inventory in the Boeun aquifer is situated near an artificial reservoir (40-70 m apart) intended to supply water to nearby cities. However, toxic radionuclides can enter the reservoir. To determine the U mobility in the system, we analyzed groundwater and fracture-filling materials (FFMs) for environmental tracers, including microbial signatures, redox-sensitive elements and isotopes. In the site, U mass flux ranged from only 9.59 × 10-7 µg/L/y to 1.70 × 10-4 µg/L/y. The δ18O-H2O and 14C signatures showed that groundwater originated mainly from upland recharges and was not influenced by oxic surface water. We observed U accumulations (∼157 mg/kg) in shallow FFMs and Fe enrichments (∼226798 mg/kg) and anomalies in the 230Th/238U activity ratio (AR), 230Th/234U AR, δ56Fe and δ57Fe isotopes, suggesting that low U mobility in shallow depths is associated with a Fe-rich environment. At shallow depths, anaerobic Fe-oxidizers, Gallionella was prevalent in the groundwater, while Acidovorax was abundant near the U ore deposit depth. The Fe-rich environment at shallow depths was formed by sulfide dissolution, as demonstrated by δ34S-SO4 and δ18O-SO4 distribution. Overall, the Fe-rich aquifer including abundant sulfide minerals immobilizes dissolved U through biotic and abiotic processes, without significant leaching into nearby reservoirs.
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Affiliation(s)
- YeoJin Ju
- Disposal Safety Evaluation Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Republic of Korea
| | - Min Hoon Baik
- Disposal Safety Evaluation Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Republic of Korea
| | - Seung Yeop Lee
- Disposal Safety Evaluation Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
| | - Dongbok Shin
- Department of Geoenvironmental Sciences, Kongju National University, Kongju 32588, Republic of Korea
| | - Ji-Hun Ryu
- Disposal Safety Evaluation Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, Republic of Korea.
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Kim J, Lee KK. Seasonal effects on hydrochemistry, microbial diversity, and human health risks in radon-contaminated groundwater areas. Environ Int 2023; 178:108098. [PMID: 37467531 DOI: 10.1016/j.envint.2023.108098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/12/2023] [Accepted: 07/12/2023] [Indexed: 07/21/2023]
Abstract
Groundwater is an important human resource. Daejeon in South Korea faces severe water quality issues, including radon, uranium, and fluoride pollution, all of which pose health risks to humans. With climate change, threats to potable water, such as heavy rain and typhoons, have become common. Therefore, examining the seasonal effects on groundwater quality and resultant health risks is important for understanding the mechanisms of different hydroclimatological conditions to enable the implementation of sustainable management plans in radon-contaminated groundwater areas. However, this issue has not yet been studied. To bridge this gap, in this study, major ions and microbial community structures were employed and groundwater quality index (GWQI) were calculated with hazard index based on limits set by the World Health Organization (WHO) to investigate the hydrochemical characterization and to assess pollution levels. The results showed that the rainy season had distinct hydrochemical characteristics with high correlations between radon and fluoride, and most groundwater samples collected after the typhoon had characteristics similar to those collected during the dry season, owing to the flow path. Furthermore, the microbial diversity and hazard quotient (HQ) values of fluoride revealed that pollution worsened during the dry season. All of the calculated effective dose values of radon exceeded the threshold limit set by the WHO, despite the low GWQI. Infants and children were particularly susceptible to radon-contaminated groundwater. The statistical results of self-organizing map (SOM) suggested that radon analysis was sufficient for public health intervention in the rainy season; however, in the dry season, combined analyses of radon, fluoride, and microbial diversity played important roles in health risk assessment. Our study presents a comprehensive understanding of radon-contaminated groundwater characteristics under seasonal effects and can serve as a reference for other similar zones to provide significant insights into the effective management of radon contamination.
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Affiliation(s)
- Jaeyeon Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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Joun WT, Lee KK, Ha SW, Lee SS, Kim Y, Do HK, Jun SC, Kim Y, Ju Y. A modified and rapid method for the single-well push-pull (SWPP) test using SF 6, Kr, and uranine tracers. Water Res 2023; 236:119955. [PMID: 37087918 DOI: 10.1016/j.watres.2023.119955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 03/28/2023] [Accepted: 04/07/2023] [Indexed: 05/03/2023]
Abstract
In the present study, a single-well push-pull (SWPP) test was conducted with multi-component tracers, including inert gas (SF6 and Kr) and uranine (conservative), to understand the volatile/semi-volatile component transport characteristics in the groundwater system. In an SWPP test, it is essential to obtain an initial breakthrough curve (BTC) of the inert gas concentration at the beginning of the pulling stage to analyze the hydraulic properties of the groundwater system. As a result of the SWPP test using a proposed method in this study, physicochemical parameters of the groundwater and BTC of gas tracers and uranine were acquired simultaneously and successfully. In addition, on-site measurements of uranine, pCO2, and water quality data, such as electrical conductivity (EC), temperature, pH, and dissolved oxygen, were undertaken. Modification of an existing pCO2 measuring system allowed the gas samples to be collected, transported, and analyzed for inert gas components within a few hours. As a result, reliable and interpretable data with a recovery ratio of 26%, 85%, and 95% for SF6, Kr, and uranine, respectively, were obtained. The differences in the recovery ratio were utilized to identify the environmental system, whether it contains gas inside the isolated system (closed) or not (open), and to understand plume behavior characteristics in the experimental zone. By applying a two-dimensional advection-dispersion model to the acquired tracer test data and comparing the observed and computed tracer concentrations, helpful information was obtained on the hydraulic and transport characteristics of the targeted zone. This method can be extended to the design of dissolved CO2 transport monitoring of an aquifer above a CCS site.
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Affiliation(s)
- Won-Tak Joun
- College of Natural Science, The Research Institute of Basic Sciences, Seoul National University, Seoul 08826, Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Science, Seoul National University, Seoul 08826, Korea.
| | - Seung-Wook Ha
- School of Earth and Environmental Science, Seoul National University, Seoul 08826, Korea
| | - Seong-Sun Lee
- College of Natural Science, The Research Institute of Basic Sciences, Seoul National University, Seoul 08826, Korea
| | - Yeji Kim
- School of Earth and Environmental Science, Seoul National University, Seoul 08826, Korea
| | - Hyun-Kwon Do
- College of Engineering and Physical Sciences, Morwick G360 Groundwater Research Institute, University of Guelph, Guelph, ON N1G2W1, Canada
| | | | - YongCheol Kim
- Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, Korea
| | - YeoJin Ju
- Korea Atomic Energy Research Institute, Daejeon 34057, Republic of Korea
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Koh EH, Kaown D, Park SH, Kim H, Lee KK. Nitrate sources, timing, and pathways of a permeable volcanic aquifer system with mixed land use in Jeju Island, South Korea. Sci Total Environ 2023; 888:164129. [PMID: 37187398 DOI: 10.1016/j.scitotenv.2023.164129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/07/2023] [Accepted: 05/09/2023] [Indexed: 05/17/2023]
Abstract
The occurrence of various N-related human activities increases the difficulty in distinguishing the major sources of NO3- contamination in groundwater, especially in areas with mixed land uses. In addition, the estimation of the timing and pathways of NO3- is necessary to better understand the processes of NO3- contamination in the subsurface aquifer system. This study applied environmental tracers, such as stable isotopes and age tracers (δ15N and δ18O of NO3-, δ11B, chlorofluorocarbons, and 3H), to elucidate the sources, timing, and pathways of NO3- contamination in the groundwaters of the Hanrim area, which has suffered from illegal disposal of livestock wastes since the 1980s, and also characterizes them based on mixed N-contaminant sources such as chemical fertilizers and sewage. The combined use of δ15N and δ11B overcame the limitation of using only NO3- isotopes for the identification of overlapping sources of N and successfully identified the major source of N as livestock wastes. The lumped parameter model (LPM) estimated the binary mixing of the young (age: 23-40 years, NO3-N: 2.55-15.10 mg/L) and old (age: >60 years, NO3-N: <3 mg/L) groundwaters, and explained their age mixing behaviors. The young groundwater was highly affected by livestock-derived N loading during 1987-1998, which coincides with the period of improper dumping of livestock wastes. Furthermore, the young groundwater with elevated NO3-N followed the historical NO3-N curves with younger ages (6 and 16 years) than those derived from the LPM, suggesting the possibility of faster inflows of livestock wastes through the permeable volcanic structures. This study demonstrated that a comprehensive understanding of NO3- contamination processes can be achieved using environmental tracer methods, which enables the efficient management of groundwater resources in areas with multiple N sources.
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Affiliation(s)
- Eun-Hee Koh
- School of Ocean and Earth Sciences, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju Special Self-Governing Province 63243, Republic of Korea
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Sun-Hwa Park
- National Institute of Environmental Research, Incheon 22689, Republic of Korea
| | - Hyunkoo Kim
- National Institute of Environmental Research, Incheon 22689, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
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Kaown D, Koh DC, Mayer B, Mahlknecht J, Ju Y, Rhee SK, Kim JH, Park DK, Park I, Lee HL, Yoon YY, Lee KK. Estimation of nutrient sources and fate in groundwater near a large weir-regulated river using multiple isotopes and microbial signatures. J Hazard Mater 2023; 446:130703. [PMID: 36587594 DOI: 10.1016/j.jhazmat.2022.130703] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 06/17/2023]
Abstract
The excessive input of nutrients into groundwater can accelerate eutrophication in associated surface water systems. This study combined hydrogeochemistry, multi isotope tracers, and microbiological data to estimate nutrient sources and the effects of groundwater-surface water interactions on the spatiotemporal variation of nutrients in groundwater connected to a large weir-regulated river in South Korea. δ11B and δ15N-NO3- values, in combination with a Bayesian mixing model, revealed that manure and sewage contributed 40 % and 25 % respectively to groundwater nitrate, and 42 % and 27 % to nitrate in surface water during the wet season. In the dry season, the source apportionment was similar for groundwater while the sewage contribution increased to 52 % of nitrate in river water. River water displayed a high correlation between NO3- concentration and cyanobacteria (Microcystis and Prochlorococcus) in the wet season. The mixing model using multiple isotopes indicated that manure-derived nutrients delivered with increased contributions of groundwater to the river during the wet season governed the occurrence of cyanobacterial blooms in the river. We postulate that the integrated approach using multi-isotopic and microbiological data is highly effective for evaluating nutrient sources and for delineating hydrological interactions between groundwater and surface water, as well as for investigating surface water quality including eutrophication in riverine and other surface water systems.
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Affiliation(s)
- Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, the Republic of Korea.
| | - Dong-Chan Koh
- Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, the Republic of Korea; University of Science and Technology, Daejeon 34113, the Republic of Korea.
| | - Bernhard Mayer
- Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada.
| | - Jürgen Mahlknecht
- Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Campus Monterey, Eugenio Garza Sada 2501, Monterrey 64149, Nuevo León, Mexico.
| | - YeoJin Ju
- Radioactive Waste Disposal Research Division, Korea Atomic Energy Research Institute, Daejeon 34057, the Republic of Korea.
| | - Sung-Keun Rhee
- Department of Biological Sciences and Biotechnology, Chungbuk National University, Cheongju 28644, the Republic of Korea.
| | - Ji-Hoon Kim
- Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, the Republic of Korea.
| | - Dong Kyu Park
- Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, the Republic of Korea.
| | - Inwoo Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, the Republic of Korea.
| | - Hye-Lim Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, the Republic of Korea.
| | - Yoon-Yeol Yoon
- Korea Institute of Geoscience and Mineral Resources, Daejeon 34132, the Republic of Korea.
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, the Republic of Korea.
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Koh EH, Lee E, Lee KK, Moon DC. Integrated application of a Bayesian mixing model, numerical model, and environmental tracers to characterize groundwater recharge sources in a mountainous area. Sci Total Environ 2022; 853:158619. [PMID: 36084785 DOI: 10.1016/j.scitotenv.2022.158619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 08/17/2022] [Accepted: 09/04/2022] [Indexed: 06/15/2023]
Abstract
In this study, the combined use of a Bayesian mixing model (BMM), numerical model (random walk particle tracking-RWPT), and environmental tracers (δ18O-δD, 3H, and CFC) was applied to elucidate the probabilistic contribution of the recharge sources, flow path, and residence time of groundwater across the mountainous area of Jeju Island, South Korea. Especially, the BMM ability to estimate the variable recharge contributions to the aquifer by different elevations and seasons was investigated. The δ18O-δD isotopes showed that groundwater in the study area was primarily fed by precipitation during the wet season, and the BMM estimated that wet season recharge contributed to approximately 64% of the total. The BMM-based probabilistic estimation of recharge sources revealed a mixed contribution of source waters from different elevations. A notable difference in recharge flow path was observed between highland (>450 masl) and lowland (<400 masl) wells, where the inflow of source water from the regional flow was dominant in the former and both regional and local recharges served as significant groundwater sources in the latter. Evidence from age tracers (3H and CFC-12) also supported different recharge mechanisms between highland and lowland wells. A reasonable match between the BMM- and RWPT-derived recharge contributions (RMSE 0.02-0.06) was achieved within the uncertainty ranges, with RWPT being particularly useful for capturing different flow paths between highland and lowland wells. The dynamics revealed here provide important information for establishing an improved and informed groundwater management plan for the mountainous area of Jeju Island. Ultimately, this study highlights the advantageous integrated analysis of BMM, RWPT, and environmental tracer analyses to enhance the reliability of recharge area estimation and increase the collective understanding of complex hydrogeological systems in mountainous areas.
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Affiliation(s)
- Eun-Hee Koh
- School of Ocean and Earth Sciences, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju Special Self-Governing Province 63243, Republic of Korea
| | - Eunhee Lee
- Korea Institute of Geoscience and Mineral Resources, 124 Gwahak-ro, Yuseong-gu, Daejeon 34132, Republic of Korea.
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Duk-Cheol Moon
- Water Resource Research Team, Jeju Special Self-Governing Province Development Co., 1717-35 Namjo-ro, Jocheon-eup, Jeju-si, Jeju Special Self-Governing Province 63345, Republic of Korea
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Ferry AV, Wereski R, Marshall L, Strachan FE, Schulberg SD, Bularga A, Chapman AR, Lee KK, Anand A, Mills NL. Exploring adherence to an early rule-out pathway for myocardial infarction in the emergency department using mixed-methods. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.1347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Incorporating a high-sensitivity cardiac troponin assay into a care pathway for the assessment of suspected acute coronary syndrome has enabled myocardial infarction to be ruled out earlier.
Purpose
Using mixed methods, we explored adherence to an early rule-out pathway in the HiSTORIC (High-Sensitivity Cardiac Troponin on Presentation to Rule Out Myocardial Infarction) randomised controlled trial.
Methods
In 16,972 consecutive patients we evaluated clinician adherence to an early rule-out pathway for the assessment of suspected acute coronary syndrome. Adherence was defined in patients with presentation cardiac troponin I concentrations <5ng/L and symptom onset >2 hours from presentation without serial troponin testing (type 1 adherence); presentation troponin <5ng/L and symptom onset ≤2 hours from presentation with serial testing (type 2 adherence); or presentation troponin between 5ng/L and sex-specific 99th centile with serial testing (type 3 adherence). Semi-structured interviews were conducted with 23 clinicians to aid interpretation of the quantitative analysis. Qualitative data were coded and organized into themes.
Results
In patients with troponin <5ng/L presenting >2hr from symptom onset, adherence was achieved in 81% of patients. In patients presenting ≤2hr from symptom onset, 35% of patients had a second troponin test. In patients with an initial troponin concentration between 5ng/L and the 99th centile, 65% of patients had a second troponin test. Compared to patients managed by clinicians who were adherent to the pathway, patients with troponin over-testing (type 1 non-adherence) were more likely to be older (mean age 52±16 years versus 58±14, P<0.001) and have a history of coronary disease (11% versus 27%, P<0.001). In contrast, patients with under testing (type 2 non-adherence) tended to be younger (mean age 49±16 versus 63±15, P<0.001), female (50% versus 37%, P<0.001) and have lower presentation troponin levels (median concentration 1.0ng/L IQR 1.0 to 2.0, versus 5.0ng/L IQR 2.0–10.0) compared to those in whom testing was performed according to pathway recommendations. Semi-structured interview data revealed how pathway adherence was influenced by five main themes: guideline characteristics, patient characteristics, the healthcare practitioner, the healthcare system and scientific evidence. Clear visual pathway layout was fundamental in achieving optimal adherence. Strong clinical suspicion of acute coronary syndrome promoted repeat troponin testing and deviation from the pathway was felt to be justifiable by more senior clinicians.
Conclusion
This analysis revealed successful implementation of the early rule-out pathway with interview data aiding interpretation of trial data. Younger patients with lower troponin concentrations were less likely to receive pathway recommended serial troponin testing. Clinical judgement is one of the main reasons for discontinuation of pathway recommendations.
Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): British Heart Foundation
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Affiliation(s)
- A V Ferry
- University of Edinburgh, Centre for Cardiovascular Science , Edinburgh , United Kingdom
| | - R Wereski
- University of Edinburgh, Centre for Cardiovascular Science , Edinburgh , United Kingdom
| | - L Marshall
- University of Edinburgh, Centre for Cardiovascular Science , Edinburgh , United Kingdom
| | - F E Strachan
- Usher Institute of Population Health Sciences and Informatics , Edinburgh , United Kingdom
| | - S D Schulberg
- University of Edinburgh, Centre for Cardiovascular Science , Edinburgh , United Kingdom
| | - A Bularga
- University of Edinburgh, Centre for Cardiovascular Science , Edinburgh , United Kingdom
| | - A R Chapman
- University of Edinburgh, Centre for Cardiovascular Science , Edinburgh , United Kingdom
| | - K K Lee
- University of Edinburgh, Centre for Cardiovascular Science , Edinburgh , United Kingdom
| | - A Anand
- University of Edinburgh, Centre for Cardiovascular Science , Edinburgh , United Kingdom
| | - N L Mills
- University of Edinburgh, Centre for Cardiovascular Science , Edinburgh , United Kingdom
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Doudesis D, Lee KK, Bularga A, Ferry AV, Tuck C, Anand A, Boeddinghaus J, Mueller C, Greenslade JH, Pickering JW, Than MP, Cullen L, Mills NL. Machine learning to optimise use of cardiac troponin in the diagnosis of acute myocardial infarction. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.1349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Guidelines recommend fixed cardiac troponin thresholds for the assessment of patients with suspected acute coronary syndrome, however, performance varies in important patient groups as concentrations are influenced by age, sex and comorbidities. This limitation can be addressed using machine learning algorithms.
Methods
Machine learning algorithms were developed that integrate cardiac troponin concentrations at presentation or on serial testing with age, sex and clinical features in 10,038 consecutive emergency patients with suspected acute coronary syndrome. The primary outcome was an adjudicated diagnosis of type 1, type 4b or type 4c myocardial infarction. The best performing algorithm was selected for the CoDE-ACS (Collaboration for the Diagnosis and Evaluation of Acute Coronary Syndrome) decision-support tool, and performance was externally validated in 3,035 patients pooled from three prospective studies.
Findings
CoDE-ACS had excellent discrimination and calibration using cardiac troponin at presentation (area under curve [AUC] 0.959, 95% confidence interval 0.948–0.971, Brier score 0.040), in the pooled external validation cohort. At presentation, the rule-out score identified 62.1% (1,885/3,035) of all patients as low-probability of myocardial infarction with a 99.5% (99.1–99.7%) negative predictive value and 97.0% (96.3–97.6%) sensitivity. The rule-in score identified 8.3% (252/3,035) of patients as high-probability with an 83.7% (82.4–85.0%) positive predictive value and 98.5% (98.0–98.9%) specificity. Performance of the rule-out and rule-in scores was consistent across patient subgroups (Figure 1 and Figure 2). CoDE-ACS incorporating a second cardiac troponin measurement also had excellent discrimination and calibration (AUC 0.971 [0.962–0.980], Brier score 0.039) and refined the individualised probabilities in the 29.5% (898/3,035) of patients neither ruled-out or ruled-in at presentation to guide further investigation.
Conclusions
We developed and externally validated the CoDE-ACS decision-support tool using machine learning to aid in the diagnosis of myocardial infarction. CoDE-ACS had excellent diagnostic performance to rule-out and rule-in myocardial infarction at presentation, performed consistently across patient subgroups, and provided individualised probabilities to guide further care in those who require serial troponin measurements.
Conclusions
We developed and externally validated the CoDE-ACS decision-support tool using machine learning to aid in the diagnosis of myocardial infarction. CoDE-ACS had excellent diagnostic performance to rule-out and rule-in myocardial infarction at presentation, performed consistently across patient subgroups, and provided individualised probabilities to guide further care in those who require serial troponin measurements.
Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health ResearchBritish Heart Foundation
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Affiliation(s)
- D Doudesis
- University of Edinburgh, Centre for Cardiovascular Sciences , Edinburgh , United Kingdom
| | - K K Lee
- University of Edinburgh, Centre for Cardiovascular Sciences , Edinburgh , United Kingdom
| | - A Bularga
- University of Edinburgh, Centre for Cardiovascular Sciences , Edinburgh , United Kingdom
| | - A V Ferry
- University of Edinburgh, Centre for Cardiovascular Sciences , Edinburgh , United Kingdom
| | - C Tuck
- University of Edinburgh, Centre for Cardiovascular Sciences , Edinburgh , United Kingdom
| | - A Anand
- University of Edinburgh, Centre for Cardiovascular Sciences , Edinburgh , United Kingdom
| | - J Boeddinghaus
- University of Basel, Cardiovascular Research Institute Basel and Department of Cardiology , Basel , Switzerland
| | - C Mueller
- University of Basel, Cardiovascular Research Institute Basel and Department of Cardiology , Basel , Switzerland
| | - J H Greenslade
- University of Queensland, School of Medicine , Brisbane , Australia
| | - J W Pickering
- University of Otago, Christchurch Heart Institute , Christchurch , New Zealand
| | - M P Than
- Christchurch Hospital , Christchurch , New Zealand
| | - L Cullen
- University of Queensland, School of Medicine , Brisbane , Australia
| | - N L Mills
- University of Edinburgh, Centre for Cardiovascular Sciences , Edinburgh , United Kingdom
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11
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Bularga A, Kimenai DM, Taggart C, Lowry M, Wereski R, McCance K, Lee KK, Anand A, Strachan FE, Tuck C, Shah ASV, Chapman AR, Newby DE, Jenks S, Mills NL. Impact of patient selection on performance of an early rule-out pathway for myocardial infarction: from research to the real world. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.1344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Early rule-out pathways for myocardial infarction using high-sensitivity cardiac troponin are widely recommended in the assessment of patients with suspected acute coronary syndrome. Although developed in selected patients participating in research studies, these pathways are applied more widely in clinical practice where the diagnostic performance and effectiveness of these pathways may differ.
Purpose
To evaluate the performance of an early rule-out pathway for myocardial infarction using high-sensitivity cardiac troponin in selected and consecutive unselected patients with suspected acute coronary syndrome.
Methods
Presentation and serial high-sensitivity cardiac troponin I concentrations were measured in two cohorts of patients with suspected acute coronary syndrome presenting to the Emergency Departments across three acute care hospitals in Scotland. In the unselected cohort, electronic health record data were collected on consecutive patients in whom the usual care clinician measured cardiac troponin for suspected acute coronary syndrome. In the selected cohort, patients with suspected acute coronary syndrome were approached between 8am and 8pm by research staff and written informed consent obtained. In both cohorts, the performance of the High-STEACS early rule-out pathway was evaluated for an adjudicated diagnosis of myocardial infarction (type 1, type 4b or type 4c) during the index hospital admission.
Results
The unselected and selected patient cohorts comprised of 1,242 (median age 60 [interquartile range 47–75] years, 46% women) and 1,695 (median age 61 [52–73] years, 40% women) patients respectively. Myocardial infarction was diagnosed in 6% (74/1,242) and 14% (232/1,695) of patients in the unselected and selected patient cohorts respectively. More patients had myocardial infarction ruled-out in the unselected (74% [828/1,112] versus 66% [1,102/1,678]; P<0.001), with similar negative predictive value (99.9% [95% CI 99.7%-100%] versus 99.7% [95% CI 99.4%-99.0%) and sensitivity (99.3% [95% CI 97.4%-100%] versus 98.9% [95% CI 97.6%-99.9%]; Figure 1). In the selected cohort, more patients had intermediate troponin concentrations requiring serial testing (36% versus 29%) or had myocardial infarction diagnosed (34% versus 26%; P<0.001 for both). In contrast, the positive predictive value for myocardial infarction was lower in unselected patients (26.1% [95% CI 21.2%-31.4%] versus 39.9% [95% CI 35.9%-44.0%]).
Conclusion
The prevalence of myocardial infarction is lower in patients with suspected acute coronary syndrome evaluated in routine practice compared to those selected to participate in a research study. Whilst more patients have myocardial infarction accurately ruled out, the positive-predictive value in those ruled in is lower resulting in more hospital admissions with elevated cardiac troponin due to other conditions.
Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart FoundationMedical Research Council
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Affiliation(s)
- A Bularga
- University of Edinburgh , Edinburgh , United Kingdom
| | - D M Kimenai
- University of Edinburgh , Edinburgh , United Kingdom
| | - C Taggart
- University of Edinburgh , Edinburgh , United Kingdom
| | - M Lowry
- University of Edinburgh , Edinburgh , United Kingdom
| | - R Wereski
- University of Edinburgh , Edinburgh , United Kingdom
| | - K McCance
- University of Edinburgh, Department Clinical Biochemistry, , Edinburgh , United Kingdom
| | - K K Lee
- University of Edinburgh , Edinburgh , United Kingdom
| | - A Anand
- University of Edinburgh , Edinburgh , United Kingdom
| | - F E Strachan
- University of Edinburgh , Edinburgh , United Kingdom
| | - C Tuck
- University of Edinburgh , Edinburgh , United Kingdom
| | - A S V Shah
- London School of Hygiene and Tropical Medicine, Department of Cardiology , London , United Kingdom
| | - A R Chapman
- University of Edinburgh , Edinburgh , United Kingdom
| | - D E Newby
- University of Edinburgh , Edinburgh , United Kingdom
| | - S Jenks
- Royal Infirmary of Edinburgh, Department of Clinical Biochemistry , Edinburgh , United Kingdom
| | - N L Mills
- University of Edinburgh , Edinburgh , United Kingdom
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12
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Ju Y, Györe D, Gilfillan SMV, Lee SS, Cho I, Ha SW, Joun WT, Kang HJ, Do HK, Kaown D, Stuart FM, Hahm D, Park K, Yun ST, Lee KK. Constraining the effectiveness of inherent tracers of captured CO 2 for tracing CO 2 leakage: Demonstration in a controlled release site. Sci Total Environ 2022; 824:153835. [PMID: 35176379 DOI: 10.1016/j.scitotenv.2022.153835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 02/03/2022] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
Geological storage of carbon dioxide (CO2) is an integral component of cost-effective greenhouse gas emissions reduction scenarios. However, a robust monitoring regime is necessary for public and regulatory assurance that any leakage from a storage site can be detected. Here, we present the results from a controlled CO2 release experiment undertaken at the K-COSEM test site (South Korea) with the aim of demonstrating the effectiveness of the inherent tracer fingerprints (noble gases, δ13C) in monitoring CO2 leakage. Following injection of 396 kg CO2(g) into a shallow aquifer, gas release was monitored for 2 months in gas/water phases in and above the injection zone. The injection event resulted in negative concentration changes of the dissolved gases, attributed to the stripping action of the depleted CO2. Measured fingerprints from inherent noble gases successfully identified solubility-trapping of the injected CO2 within the shallow aquifer. The δ13C within the shallow aquifer could not resolve the level of gas trapping, due to the interaction with heterogeneous carbonate sources in the shallow aquifer. The time-series monitoring of δ13CDIC and dissolved gases detected the stripping action of injected CO2(g), which can provide an early warning of CO2 arrival. This study highlights that inherent noble gases can effectively trace the upwardly migrating and fate of CO2 within a shallow aquifer.
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Affiliation(s)
- YeoJin Ju
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea; Disposal Safety Evaluation Research Division, Korea Atomic Energy Research Institute, Daejeon, South Korea
| | - Domokos Györe
- Isotope Geosciences Unit, Scottish Universities Environmental Research Centre (SUERC), East Kilbride G75 0QF, Scotland, United Kingdom
| | - Stuart M V Gilfillan
- School of GeoSciences, University of Edinburgh, Grant Institute, James Hutton Road, Edinburgh EH9 3FE, UK
| | - Seong-Sun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Ilryoung Cho
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Seung-Wook Ha
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Won-Tak Joun
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Hyun-Ji Kang
- Department of Earth and Environmental Sciences, Korea University, Seoul 02841, South Korea
| | - Hyun-Kwon Do
- Morwick G360 Groundwater Research Institute, College of Engineeringand Physical Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Finlay M Stuart
- Isotope Geosciences Unit, Scottish Universities Environmental Research Centre (SUERC), East Kilbride G75 0QF, Scotland, United Kingdom
| | - Doshik Hahm
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Keyhong Park
- Korea Polar Research Institute (KOPRI), Incheon, South Korea
| | - Seong-Taek Yun
- Department of Earth and Environmental Sciences, Korea University, Seoul 02841, South Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea.
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13
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Ryu HS, Kim H, Lee JY, Kaown D, Lee KK. Abnormal groundwater levels and microbial communities in the Pohang Enhanced Geothermal System site wells pre- and post-M w 5.5 earthquake in Korea. Sci Total Environ 2022; 810:152305. [PMID: 34906576 DOI: 10.1016/j.scitotenv.2021.152305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
In this study, two geothermal wells (PX-1 and PX-2) exhibiting abnormal groundwater levels and microbial communities were examined at the Enhanced Geothermal System site before and after the Pohang earthquake (November 2017). Furthermore, the EXP-1 well level, water temperature, microbial communities and their association with earthquakes, as well as the possibility of future earthquakes were explored. The primary objectives of this research were to: (1) perform correlation and cluster analyses of hydrophysical parameters for earthquakes using next-generation sequencing; (2) analyze pre-, co-, and post-seismic changes in groundwater levels, temperatures, and microbial communities; and (3) further assess the analyzed results of the post-earthquake changes in the groundwater levels and temperatures to interpret their implications. Although the pre-earthquake water levels in the three wells were unknown, their depth-to-water levels post-earthquake ranged from 50.33-98.20 m, 570.91-735.00 m, and 47.70-56.04 m for wells PX-1 (depth 4362 m), PX-2 (4348 m), and EXP-1 (180 m), respectively. In particular, the water levels of PX-2 were abnormally low compared with the surrounding area. Moreover, the geothermal wells demonstrated unstable microbial communities prior to the earthquake. However, while the microbial communities of PX-1 recovered relatively quickly post-earthquake, those of PX-2 failed to stabilize even within two years after the earthquake. Thus, it was inferred here that the PX-2 well is more closely related to seismic activity, the effects of which can still be seen. Accordingly, it is important that PX-2 is continuously monitored until June 2024, the minimum period predicted for the water levels to reach stability.
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Affiliation(s)
- Han-Sun Ryu
- Department of Geology, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Heejung Kim
- Department of Geology, Kangwon National University, Chuncheon 24341, Republic of Korea.
| | - Jin-Yong Lee
- Department of Geology, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
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14
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Choi H, Lee H, Kim DH, Lee KK, Kim Y. Physicochemical and isotopic properties of ambient aerosols and precipitation particles during winter in Seoul, South Korea. Environ Sci Pollut Res Int 2022; 29:11990-12008. [PMID: 34558045 DOI: 10.1007/s11356-021-16328-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/30/2021] [Indexed: 06/13/2023]
Abstract
The aim of this study was to characterize the physicochemical properties and microbial communities of particulate matter (PM) in Seoul, Korea. We collected long-term (2017-2019) precipitation samples and PM10 and PM2.5 monitoring data to determine the impact of soluble and insoluble chemical species on the soil surface. Ambient PM10 concentrations were higher than PM2.5 concentrations during the monitoring period, but both decreased during rainfall due to the washing effect of precipitation. PM2.5 particles had a "fluffy" shape and contained sulfur (0.2%), but suspended particles (SPs) contained many carbon particles (approximately 60%). Spherical particles containing metal oxides, Fe and Al, might be originated from coal combustion, wild fires, and metal-refining processes under high-temperature conditions. Dissolved ions in precipitation included those eluted from salts and coal combustion based on the correlation coefficients of Na and Cl (R = 0.953) and F and NO3 (R = 0.706). The δ15N-NO3 and δ34S-SO4 of precipitation were enriched as the atmospheric temperature decreased from 9.8 to -1.6°C, implying the influence of domestic coal combustion. Backward trajectories showed that, in winter, air parcels passed through industrialized cities from China to South Korea. The microbial communities associated with PM were strongly influenced by atmospheric conditions. Proteobacteria (range from 4.6 to 76.7%) and Firmicutes (range from 6.0 to 91.4%) were the most dominant phyla and were significantly affected by changes in the PM2.5 environment. The results indicate that the acidity of precipitation and the composition of aerosols were affected by fossil fuel combustion and mineral dust, and that atmospheric conditions may change as PM2.5 concentrations increase.
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Affiliation(s)
- Hanna Choi
- Groundwater Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon, 34132, Korea
| | - Heejo Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwank-ro, Seoul, 08826, Korea
| | - Dong-Hun Kim
- Groundwater Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon, 34132, Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwank-ro, Seoul, 08826, Korea.
| | - Yongcheol Kim
- Groundwater Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon, 34132, Korea
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15
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Hwang HT, Neupauer RM, Jeen SW, Steinmoeller DT, Sudicky EA, Lee SS, Lee KK. Evaluating backward probability model under various hydrogeologic and hydrologic conditions. J Contam Hydrol 2022; 244:103909. [PMID: 34839109 DOI: 10.1016/j.jconhyd.2021.103909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/19/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Contaminant source identification improves the understanding of contaminant source characteristics including location and release time, which can lead to more effective remediation and water resources management plans. The backward probability model can provide probabilities of source locations and release times under various contaminant properties and hydrogeologic conditions. The backward probability model has been applied to numerous synthetic and real contamination sites for locating possible contaminant sources, but it is also important to evaluate the reliability of the backward probability model through rigorous verification analyses. Here, we present a model verification framework for the backward probability model using a stepwise approach from simple to complex model settings: comparison with previous studies, transient saturated flow under various hydrogeologic conditions, and transient variably-saturated flow conditions. As a simple condition, one-dimensional homogeneous problems under steady-state and transient flow conditions were verified by comparing with previous studies. Model verifications with complex conditions were conducted by comparing forward and backward probability simulation results. The verification results demonstrate that the backward probability model performs well for homogeneous problems. For heterogeneous problems, the backward probability model results in slightly different backward travel times due to differences in solute decay and boundary conditions assigned for both forward and backward probability simulations, but the backward travel time at the maximum probability can be reproduced well.
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Affiliation(s)
- Hyoun-Tae Hwang
- Aquanty, Inc., 564 Weber Street North, Unit 2, Waterloo, ON, N2L 5C6, Canada; Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Roseanna M Neupauer
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Boulder, CO 80309-0428, USA
| | - Sung-Wook Jeen
- Department of Earth and Environmental Sciences & The Earth and Environmental Science System Research Center, Jeonbuk National University, Jeonju-si, Jeollabuk-do 54896, Republic of Korea; Department of Environment and Energy, Jeonbuk National University, Jeonju-si, Jeollabuk-do 54896, Republic of Korea.
| | | | - Edward A Sudicky
- Aquanty, Inc., 564 Weber Street North, Unit 2, Waterloo, ON, N2L 5C6, Canada; Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Seong-Sun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
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16
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Doudesis D, Lee KK, Anwar M, Astengo F, Newby D, Japp A, Tsanas A, Shah A, Richards M, McMurray J, Mueller C, Januzzi J, Mills N. Machine learning to aid in the diagnosis of acute heart failure in the emergency department. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.1040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
B-type natriuretic peptide (BNP) and mid-regional pro-atrial natriuretic peptide (MRproANP) testing are recommended to aid in the diagnosis of acute heart failure. However, the application of these biomarkers for optimal diagnostic performance is uncertain.
Methods
We performed a systematic review and harmonised individual patient-level data to evaluate the diagnostic performance of BNP and MRproANP for the diagnosis of acute heart failure using random-effects meta-analysis. We subsequently developed and externally validated a decision-support tool called CoDE-HF for both BNP and MRproANP that combines the natriuretic peptide concentrations with clinical variables using machine learning to report the probability of acute heart failure for an individual patient.
Results
Fourteen studies from 12 countries provided individual patient-level data in 8,493 patients for BNP and 3,847 patients for MRproANP, in whom, 48.3% (4,105/8,493) and 41.3% (1,611/3899) had an adjudicated diagnosis of acute heart failure, respectively. The negative and positive predictive values of guideline-recommended thresholds for BNP (100 pg/mL) and MR-proANP (120 pg/mL) were 93.6% (95% confidence interval 88.4–96.6%) and 68.8% (62.9–74.2%), and 95.6% (92.2–97.6%) and 64.8% (56.3–72.5%), respectively. However, we observed significant heterogeneity in the diagnostic performance across important patient subgroups (Figure 1). In the external validation cohort, CoDE-HF was well calibrated with excellent discrimination in those without prior acute heart failure for both BNP and MRproANP (area under the curve of 0.946 [0.933–0.958] and 0.943 [0.921–0.964], and Brier scores of 0.105 and 0.073, respectively). CoDE-HF performed consistently across all subgroups for both BNP and MRproANP, and identified 30% and 65.7% at low-probability (negative predictive value of 99.1% [98.8–99.3%] and 99.1% [98.8–99.4%]), and 30% and 17.3% at high-probability (positive predictive value of 91.3% [90.7–91.9%] and 70.0% [68.5–71.4%]) in those without prior heart failure, respectively (Figure 2).
Conclusion
In an international collaborative analysis, we observed that guideline-recommended thresholds for BNP and MRproANP to diagnose acute heart failure varied significantly across patient subgroups. A decision-support tool using machine learning to combine natriuretic peptides as a continuous measure and other clinical variables provides a more accurate and individualised approach.
Funding Acknowledgement
Type of funding sources: Other. Main funding source(s): Medical Research Council and British Heart Foundation Figure 1. NPV of BNP threshold (100 pg/mL)Figure 2. NPV of the CoDE-HF rule-out score
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Affiliation(s)
- D Doudesis
- University of Edinburgh, Centre for Cardiovascular Sciences, Edinburgh, United Kingdom
| | - K K Lee
- University of Edinburgh, Centre for Cardiovascular Sciences, Edinburgh, United Kingdom
| | - M Anwar
- University of Edinburgh, Centre for Cardiovascular Sciences, Edinburgh, United Kingdom
| | - F Astengo
- University of Edinburgh, Centre for Cardiovascular Sciences, Edinburgh, United Kingdom
| | - D Newby
- University of Edinburgh, Centre for Cardiovascular Sciences, Edinburgh, United Kingdom
| | - A Japp
- University of Edinburgh, Centre for Cardiovascular Sciences, Edinburgh, United Kingdom
| | - A Tsanas
- University of Edinburgh, Usher Institute, Edinburgh, United Kingdom
| | - A Shah
- University of Edinburgh, Centre for Cardiovascular Sciences, Edinburgh, United Kingdom
| | - M Richards
- University of Otago, Christchurch Heart Institute, Christchurch, New Zealand
| | - J McMurray
- University of Glasgow, BHF Cardiovascular Research Centre, Glasgow, United Kingdom
| | - C Mueller
- University Hospital Basel, Cardiovascular Research Institute of Basel, Basel, Switzerland
| | - J Januzzi
- Massachusetts General Hospital, Division of Cardiology, Boston, Massachusetts, United States of America
| | - N Mills
- University of Edinburgh, Centre for Cardiovascular Sciences, Edinburgh, United Kingdom
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17
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Bularga A, Wereski R, Taggart C, Lowry M, Singh T, Lee KK, Anand A, Shah ASV, Ross DA, Perry MR, Dweck MR, Newby DE, Chapman AR, Mills NL. Mechanisms of myocardial injury and clinical outcomes in patients hospitalised with suspected COVID-19. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.1154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Myocardial injury is associated with adverse outcomes in patients with COVID-19. However, the prognostic role of myocardial injury in COVID-19 compared to other acute illnesses and the underlying mechanisms of injury are poorly understood.
Methods
In a prospective, multi-centre, cohort study conducted in secondary and tertiary care hospitals in Scotland, all consecutive patients with suspected COVID-19 underwent cardiac troponin (ARCHITECTSTAT high-sensitive troponin I (hs-cTnI) assay; Abbott Laboratories) testing in plasma that was surplus to clinical requirements. The results were not reported unless required by the attending clinician. We evaluated the prevalence of myocardial injury, mechanisms and outcomes in all patients. In those with any hs-cTnI concentration above the sex-specific 99th centile the diagnosis was adjudicated according to the 4th Universal Definition of Myocardial Infarction. The primary outcome of all-cause mortality was compared in those with and without myocardial injury and COVID-19 by cox regression adjusted for age, sex, renal function and co-morbidities.
Results
A total of 2,916 (median age 69 [interquartile range, IQR 54–79] years, 53% women) consecutive patients with suspected COVID-19 were followed up for 228 [IQR 203–249] days. Myocardial injury occurred in 26% (750/2,916) with a median troponin concentration of 66 [35–178] ng/L; the prevalence was 41% (46/112) and 25% (704/2,804) in those with and without COVID-19, respectively. The most common mechanism was acute non-ischaemic myocardial injury occurring in 80% (37/46) and 71% (502/704) of patients with and without COVID-19, respectively. Type 1 myocardial infarction (2% and 4%), type 2 myocardial infarction (7% and 14%) and chronic myocardial injury (11% and 11%) were less common and only one patient had confirmed myocarditis. In patients with myocardial injury mortality was increased compared to those without (P<0.001 log rank), whether they had COVID-19 (54% [25/46] versus 26% [17/66]) or not (35% [248/704] versus 14% [294/2100]). Myocardial injury was an independent predictor of death in all patients (adjusted hazard ratio [aHR] 2.04, 95% confidence interval [CI] 1.71 to 2.43), but this excess risk was not higher in patients with COVID-19 (aHR 1.58, 95% CI 0.75 to 3.15) compared to those without the condition (aHR 2.01, 95% CI 1.81 to 2.49).
Conclusion
Myocardial injury is common in hospitalised patients with suspected COVID-19 whether or not COVID-19 was the cause of their presentation. The majority of patients had acute non-ischaemic myocardial injury rather than a defined cardiac condition. Despite this the presence of myocardial injury was an independent predictor of death in all hospitalised patients.
Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation Kaplan-Meier curve for all-cause death
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Affiliation(s)
- A Bularga
- University of Edinburgh, Edinburgh, United Kingdom
| | - R Wereski
- University of Edinburgh, Edinburgh, United Kingdom
| | - C Taggart
- University of Edinburgh, Edinburgh, United Kingdom
| | - M Lowry
- University of Edinburgh, Edinburgh, United Kingdom
| | - T Singh
- University of Edinburgh, Edinburgh, United Kingdom
| | - K K Lee
- University of Edinburgh, Edinburgh, United Kingdom
| | - A Anand
- University of Edinburgh, Edinburgh, United Kingdom
| | - A S V Shah
- London School of Hygiene and Tropical Medicine, Department of Cardiology, London, United Kingdom
| | - D A Ross
- Western General Hospital, Regional Infectious Disease Unit, Edinburgh, United Kingdom
| | - M R Perry
- Western General Hospital, Regional Infectious Disease Unit, Edinburgh, United Kingdom
| | - M R Dweck
- University of Edinburgh, Edinburgh, United Kingdom
| | - D E Newby
- University of Edinburgh, Edinburgh, United Kingdom
| | - A R Chapman
- University of Edinburgh, Edinburgh, United Kingdom
| | - N L Mills
- University of Edinburgh, Edinburgh, United Kingdom
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18
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Kaown D, Lee KK, Kim J, Woo JU, Lee S, Park IW, Lee D, Lee JY, Kim H, Ge S, Yeo IW. Earthquakes and very deep groundwater perturbation mutually induced. Sci Rep 2021; 11:13632. [PMID: 34211020 PMCID: PMC8249596 DOI: 10.1038/s41598-021-92937-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/15/2021] [Indexed: 02/06/2023] Open
Abstract
We report unique observations from drilling and hydraulic stimulation at a depth of approximately 4.3 km in two Enhanced Geothermal System (EGS) wells at the Pohang EGS site, South Korea. We surveyed drilling logs and hydraulic stimulation data, simulated pore pressure diffusion around the fault delineated by seismic and drilling log analyses, conducted acoustic image logging through the EGS wells, observed significant water level drops (740 m) in one of the two EGS wells, and obtained hydrochemical and isotopic variation data in conjunction with the microbial community characteristics of the two EGS wells. We discuss the hydraulic and hydrochemical responses of formation pore water to a few key seismic events near the hypocenter. We focused on how the geochemistry of water that flowed back from the geothermal wells changed in association with key seismic events. These were (1) a swarm of small earthquakes that occurred when a significant circulation mud loss occurred during well drilling, (2) the MW 3.2 earthquake during hydraulic stimulation, and (3) the MW 5.5 main shock two months after the end of hydraulic stimulation. This study highlights the value of real-time monitoring and water chemistry analysis, in addition to seismic monitoring during EGS operation.
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Affiliation(s)
- Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Korea.
| | - Jaeyeon Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Korea
| | - Jeong-Ung Woo
- Department of Geophysics, Stanford University, Stanford, CA, 94305, USA
| | - Sanghoon Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Korea
| | - In-Woo Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Korea
| | - Daeha Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Korea
| | - Jin-Yong Lee
- Department of Geology, Kangwon National University, Chuncheon, 24341, Korea
| | - Heejung Kim
- Department of Geology, Kangwon National University, Chuncheon, 24341, Korea
| | - Shemin Ge
- Geological Sciences, University of Colorado, Boulder, 80309, USA
| | - In-Wook Yeo
- Department of Geological and Environmental Sciences, Chonnam National University, Gwangju, 61186, Korea
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19
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Lee S, Kaown D, Koh EH, Ko KS, Lee KK. Delineation of groundwater quality locations suitable for target end-use purposes through deep neural network models. J Environ Qual 2021; 50:416-428. [PMID: 33576503 DOI: 10.1002/jeq2.20206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Groundwater is the main source of water for beverages, and its quality varies depending on extraction location; this is particularly the case in regions with complex geology, topography, and multiple forms of land use. Thus, it is important to determine a suitable groundwater extraction location based on intended water use and the related water quality standards. In this study, deep neural network (DNN) models and GIS data relating to groundwater quality were applied to estimate potential maps of Gangwon Province in South Korea, where groundwater is frequently extracted for drinking purposes. These maps specify areas where the groundwater quality is conducive for being used as mineral water and water for brewing coffee (hereafter referred as "coffee water"). Sensitivity analysis identified how inputs were sensitive to model estimation and showed that land-use variables were the most sensitive. The importance of each variable quantified how good or bad its region is for the desired groundwater. The overall features of importance were similar between mineral water and coffee water. However, with differences in hydrogeological units, carbonate rock was a variable of high positive importance for mineral water; metamorphic rock was its equivalent for coffee water. Our results offer a potential map of desired groundwater quality in the absence of a detailed understanding of the underlying hydrochemical processes governing groundwater quality. Additionally, the development of such a potential mapping model can help to determine the appropriate development area of groundwater for their respective purposes.
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Affiliation(s)
- Sanghoon Lee
- School of Earth and Environmental Sciences, Seoul National Univ., Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National Univ., Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Eun-Hee Koh
- School of Earth and Environmental Sciences, Seoul National Univ., Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Kyung-Seok Ko
- Korea Institute of Geoscience and Mineral Resources, Daejeon, 34132, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National Univ., Gwanak-gu, Seoul, 08826, Republic of Korea
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20
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Ju Y, Massoudieh A, Green CT, Lee KK, Kaown D. Complexity of groundwater age mixing near a seawater intrusion zone based on multiple tracers and Bayesian inference. Sci Total Environ 2021; 753:141994. [PMID: 32906048 DOI: 10.1016/j.scitotenv.2020.141994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/06/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
Aquifer flow systems near seawater interfaces can be complicated by density-driven flows and the formation of stagnation zones, which inevitably introduces uncertainty into groundwater age-dating. While age-dating has proved effective to understand the seawater intrusion and aquifer salinization process in coastal aquifers, further efforts are needed to propagate model and data uncertainty to the uncertainty associated with the inferred age distributions. This study was performed in a coastal aquifer located close to the Yellow Sea, South Korea, where there is a decreasing trend of groundwater levels due to recent heavy exploitation, raising a warning of induced seawater intrusion. We inferred the groundwater age distributions in wells around the intrusion zone and estimated the uncertainty associated with the inference based on multiple age tracers including 3H, tritiogenic 3He, radiogenic 4He, CFC-11, CFC-12 and CFC-113 using Bayesian inference. We examined various models representing the age distributions including traditional parametric Lumped Parameter Models (LPMs) and two non-parametric "shape-free" models. The results showed that the mean ages at the study site ranged from 10.9 to 522.5 y. Complex, multimodal distributions of ages occurred near a seawater intrusion area and upland recharge zones, implying converging paths of a wide range of different ages in those regions. In particular, the age distributions estimated near the seawater intrusion interface were characterized by heavy-tailed mixing structures with elevated concentrations of 4He. This likely indicates density-driven upward flow at the seawater intrusion interface, forcing old groundwater rich in 4He into the shallow aquifer. The Bayesian inference estimated large uncertainties particularly for the old age distributions, which was attributed partly to the gradual accumulation of 4He in groundwater. The Bayesian inference improved understanding of flow dynamics at a complex seawater interface and identified opportunities to further reduce uncertainty of old water age estimates that characterize upwelling groundwater near the interface.
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Affiliation(s)
- YeoJin Ju
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea.
| | - Arash Massoudieh
- Civil and Environmental Engineering, The Catholic University of America, Washington, DC, USA.
| | - Christopher T Green
- U.S. Geological Survey, Water Resources Mission Area, Moffett Field, CA, USA.
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea.
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea.
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21
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Kaown D, Koh EH, Mayer B, Ju Y, Kim J, Lee HL, Lee SS, Park DK, Lee KK. Differentiation of natural and anthropogenic contaminant sources using isotopic and microbial signatures in a heavily cultivated coastal area. Environ Pollut 2021; 273:116493. [PMID: 33484997 DOI: 10.1016/j.envpol.2021.116493] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/21/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
Hydrogeochemical and multiple isotope data for groundwater samples were obtained and interpreted to discriminate anthropogenic and natural contaminant sources in a coastal aquifer underlying a heavily cultivated watershed in Hwaseong, South Korea. The local aquifers are vulnerable to contamination, due to high anthropogenic N inputs and the location close to the ocean facilitating seawater intrusion. Thus, to effectively control the groundwater quality in the study area, it is necessary to differentiate between anthropogenic and natural contaminant sources. The concentrations of NO3-N in the groundwater ranged between 0.14 and 45.6 mg/L in August 2015 and 0.2-39.6 mg/L in March 2016. High concentrations of Cl- (388-1107 mg/L) and a high electrical conductivity (1027-2715 μS/cm) were observed in the study area, suggesting that the groundwater was affected by seawater intrusion. Furthermore, δ15N-NO3-, δ34S-SO42- values and 87Sr/86Sr of groundwater were determined to reveal the origins of the natural and anthropogenic contaminants and the groundwater mean residence times (MRT) and 87Sr/86Sr ratios were used to assess the hydrogeochemical processes along the flow path in the study area. Young groundwater was affected by an anthropogenic contamination source with contributions of 26-46% adding nitrate to the aquifer, whereas old groundwater was impacted by mixing with seawater with contributions of 10-20% with low concentrations of NO3-N, but elevated concentrations of chloride and sulfate. Recently recharged uncontaminated groundwater showed oxic conditions with a diverse microbial community structure, whereas young groundwater contaminated by anthropogenic sources showed a less diverse microbial community structure. The results of this study suggest that multiple isotopes combined with groundwater MRT and microbial data can be applied to distinguish natural and anthropogenic contaminant sources in a groundwater system.
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Affiliation(s)
- Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Eun-Hee Koh
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Bernhard Mayer
- Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4, Canada
| | - YeoJin Ju
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jaeyeon Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Hye-Lim Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seong-Sun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dong Kyu Park
- Korea Institute of Geoscience and Mineral Resources, Daejeon, 34132, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
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22
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Cho I, Ju Y, Lee SS, Kaown D, Lee KK. Characterization of a NAPL-contaminated site using the partitioning behavior of noble gases. J Contam Hydrol 2020; 235:103733. [PMID: 33113508 DOI: 10.1016/j.jconhyd.2020.103733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 10/05/2020] [Accepted: 10/12/2020] [Indexed: 06/11/2023]
Abstract
Noble gases have been used for oil field exploration due to their partitioning behavior in oil-water systems. However, their application to study sites contaminated with non-aqueous phase liquids (NAPL) has been limited, except for 222Rn, which has been traditionally used as a partitioning tracer for contaminated sites. This study applied natural noble gas components such as 222Rn, He, Ne, Ar, Kr, and Xe to the characterization of a field site contaminated with trichloroethylene (TCE) located in Wonju, Korea. Groundwater at the site showed a maximum level of TCE that exceeded 1000 μg/L, with an approximate average of 400 μg/L, indicating the presence of residual TCE in the subsurface system even after remediation. The traditional tracer (i.e., 222Rn) was first used to characterize residual TCE. However, its heterogeneous distribution throughout the fractured bedrock aquifer negated its usefulness as a TCE indicator. The use of radiogenic 4He was also limited by the wide distribution of radiogenic sources on the site. By contrast, changes in the TCE level had clear effects on the conditions of other noble gases, such as Ne, Ar, and Xe, making them useful for characterization of the TCE-contaminated site. Furthermore, calculation of the TCE/water ratio including residual TCE was achieved, but identification of the TCE originating from the vadose zone was relatively hard. The results of this study indicate that based on their partitioning behavior, naturally-occurring noble gases can be used to delineate and quantify residual TCE.
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Affiliation(s)
- Ilryoung Cho
- School of Earth and Environmental Sciences, Seoul National University, 1, Gwanak-Ro, Gwanak-Gu, Seoul 08826, Republic of Korea
| | - YeoJin Ju
- School of Earth and Environmental Sciences, Seoul National University, 1, Gwanak-Ro, Gwanak-Gu, Seoul 08826, Republic of Korea
| | - Seong-Sun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1, Gwanak-Ro, Gwanak-Gu, Seoul 08826, Republic of Korea
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, 1, Gwanak-Ro, Gwanak-Gu, Seoul 08826, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1, Gwanak-Ro, Gwanak-Gu, Seoul 08826, Republic of Korea.
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23
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Koh EH, Lee E, Lee KK. Application of geographically weighted regression models to predict spatial characteristics of nitrate contamination: Implications for an effective groundwater management strategy. J Environ Manage 2020; 268:110646. [PMID: 32389899 DOI: 10.1016/j.jenvman.2020.110646] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/27/2020] [Accepted: 04/21/2020] [Indexed: 05/03/2023]
Abstract
Groundwater nitrate contamination has been the main water quality problem threatening the sustainable utilization of water resources in Jeju Island, South Korea. The spatially varying distribution of nitrate levels associated with complex environmental and anthropogenic factors has been a major challenge restricting improved groundwater management. In this study, we applied ordinary least squares (OLS) regression and geographically weighted regression (GWR) models to determine the relationships between the NO3-N concentration and various parameters (topography, hydrology and land use) across the island. A comparison between the OLS regression and GWR prediction models showed that the GWR models outperformed the OLS regression models, with a higher R2 and a lower corrected Akaike Information Criterion (AICc) value than the OLS regression models. Interestingly, the GWR model was able to provide undiscovered information that was not revealed in the OLS regression models. For example, the GWR model found that orchards (OR) and urban (UR) variables significantly contributed to nitrate enrichment in the certain parts of the island, whereas these variables were ignored as a statistically insignificant factor in the OLS regression model. Our study highlighted that GWR models are a useful tool for investigating spatially varying relationships between groundwater quality and environmental factors; therefore, it can be applied to establish advanced groundwater management plans by reflecting the spatial heterogeneity associated with environmental and anthropogenic conditions.
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Affiliation(s)
- Eun-Hee Koh
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Eunhee Lee
- Korea Institute of Geoscience and Mineral Resources, 124 Gwahak-ro, Yuseong-gu, Daejeon, 34132, Republic of Korea.
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
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24
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Joun WT, Lee KK. Reproducing natural variations in CO 2 concentration in vadose zone wells with observed atmospheric pressure and groundwater data. J Environ Manage 2020; 266:110568. [PMID: 32310117 DOI: 10.1016/j.jenvman.2020.110568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/26/2020] [Accepted: 04/04/2020] [Indexed: 06/11/2023]
Abstract
Continuous CO2 gas monitoring was performed to understand the natural variations of the gas concentration in the vadose zone wells. The monitoring results demonstrated sudden rise and fall signals, which posed a possibility of error in interpreting the CO2 leaking signal from the sequestrating reservoir or evaluating the quantity of removed VOCs at a contaminated site. Based on the monitoring data, conceptual models were established and three cases were numerically simulated to determine whether or not reproducing the natural variations of gas concentration is possible. The simulated numerical model indicated that the atmospheric pressure and groundwater level data should be considered together, rather just only one boundary condition each (top or bottom). Reproducing the natural pattern of the target gas and understanding the gas flow and transport under real closed natural conditions would also be useful. The results demonstrated the need for numerical simulation to predict the natural pattern of the CO2 gas concentration before designing or performing actual CO2 release test or CO2 leakage monitoring in the wells of the vadose zone, as well as at the geologic carbon sequestration site.
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Affiliation(s)
- Won-Tak Joun
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
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25
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Lee KK, Ellsworth WL, Giardini D, Townend J, Ge S, Shimamoto T, Yeo IW, Kang TS, Rhie J, Sheen DH, Chang C, Woo JU, Langenbruch C. Managing injection-induced seismic risks. Science 2019; 364:730-732. [PMID: 31123121 DOI: 10.1126/science.aax1878] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Republic of Korea
| | - William L Ellsworth
- Stanford Center for Induced and Triggered Seismicity, Department of Geophysics, Stanford University, Stanford, CA, USA.
| | - Domenico Giardini
- Energy Science Center, Department of Earth Sciences, ETH, Zurich, Switzerland
| | - John Townend
- School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Shemin Ge
- Department of Geological Sciences, University of Colorado, Boulder, CO, USA
| | - Toshihiko Shimamoto
- State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing, China
| | - In-Wook Yeo
- Faculty of Earth Systems and Environmental Sciences, Chonnam National University, Gwangju, Republic of Korea
| | - Tae-Seob Kang
- Department of Earth and Environmental Sciences, Pukyong National University, Busan, Republic of Korea
| | - Junkee Rhie
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Republic of Korea
| | - Dong-Hoon Sheen
- Faculty of Earth Systems and Environmental Sciences, Chonnam National University, Gwangju, Republic of Korea
| | - Chandong Chang
- Department of Geological Sciences, Chungnam National University, Daejeon, Republic of Korea
| | - Jeong-Ung Woo
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Republic of Korea
| | - Cornelius Langenbruch
- Stanford Center for Induced and Triggered Seismicity, Department of Geophysics, Stanford University, Stanford, CA, USA
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26
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Bularga A, Anand A, Strachan FE, Lee KK, Stewart S, Ferry AV, Chapman AR, Marshall L, Shah ASV, Newby DE, Mills NL. 247Safety and efficacy of high-sensitivity cardiac troponin for risk stratification in patients with suspected acute coronary syndrome. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz747.0064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Guidelines acknowledge the emerging role of high-sensitivity cardiac troponin (hs-cTn) assays for the risk stratification and rapid rule-out of myocardial infarction, but multiple approaches have been described. We previously demonstrated the utility of a single hs-cTnI concentration <5 ng/L at presentation to risk stratify patients with suspected acute coronary syndrome (ACS).
Purpose
To assess the safety and efficacy of a hs-cTnI concentration <5 ng/L at presentation in consecutive patients included in the High-STEACS (High-SensitivityTroponin in the Evaluation of patients with Acute Coronary Syndrome) randomised controlled trial.
Methods
The High-STEACS trial was a stepped wedge cluster randomised controlled trial in ten hospitals across Scotland that included 48,282 patients in whom high-sensitivity cardiac troponin was requested by the attending clinician for evaluation of suspected ACS. Patients with ST-segment elevation myocardial infarction (STEMI) were excluded. We evaluated the negative predictive value (NPV) and sensitivity of a presentation hs-cTnI <5 ng/L for a composite outcome of type 1 myocardial infarction, or subsequent type 1 myocardial infarction or cardiac death at 30 days. To assess safety, we report the one-year risk of type 1 myocardial infarction or cardiac death. To assess efficacy, we report the proportion of patients with cardiac troponin <5 ng/L at presentation.
Results
We included 47,101 consecutive patients in the analysis (mean 61±17 years old, 47% female). Of these patients, 27,500 (58%) had a cardiac troponin <5 ng/L at presentation. Overall, 4,313/47,101 (9%) patients had a composite outcome at 30 days, but the event rate was only 0.4% in those with troponin <5 ng/L (98/27,500). The NPV for the composite outcome in those <5 ng/L was 99.7% (95% confidence intervals [CI] 99.6–99.7) and the sensitivity was 98.0% (95% CI 97.6–98.4). In those without evidence of myocardial injury at presentation (hs-cTnI <99thcentile), type 1 myocardial infarction or cardiac death at one year occurred in 197 (0.7%) patients with cardiac troponin <5 ng/L, compared to 647 (5.5%) of those ≥5 ng/L. The NPV was unchanged across all age groups, although efficacy fell as fewer older patients had hs-cTnI concentrations below the risk stratification threshold (see Figure).
Conclusion
A hs-cTnI concentration <5 ng/L at presentation identifies the majority of patients with suspected ACS as low-risk of early or late cardiac events. Although the proportion identified as low risk is reduced in older populations, the safety of this risk stratification approach is maintained across patients of all ages.
Acknowledgement/Funding
British Heart Foundation
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Affiliation(s)
- A Bularga
- University of Edinburgh, Edinburgh, United Kingdom
| | - A Anand
- University of Edinburgh, Edinburgh, United Kingdom
| | - F E Strachan
- University of Edinburgh, Edinburgh, United Kingdom
| | - K K Lee
- University of Edinburgh, Edinburgh, United Kingdom
| | - S Stewart
- University of Edinburgh, Edinburgh, United Kingdom
| | - A V Ferry
- University of Edinburgh, Edinburgh, United Kingdom
| | - A R Chapman
- University of Edinburgh, Edinburgh, United Kingdom
| | - L Marshall
- University of Edinburgh, Edinburgh, United Kingdom
| | - A S V Shah
- University of Edinburgh, Edinburgh, United Kingdom
| | - D E Newby
- University of Edinburgh, Edinburgh, United Kingdom
| | - N L Mills
- University of Edinburgh, Edinburgh, United Kingdom
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27
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Shah A, McAllister D, Astengo F, Perez J, Lee KK, Gallacher P, Hall J, Bing R, Anand A, Newby D, Mills N, Cruden N. 3325Incidence, outcomes and microbiology in patients with infective endocarditis. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz745.0077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Introduction
Despite recent improvements in management, infective endocarditis remains associated with high morbidity and mortality. Over the last few decades, several factors have impacted on both the incidence and outcomes following infective endocarditis.
Purpose
Using a national linkage approach, we describe the changing age- and sex-stratified incidence and outcomes of infective endocarditis in Scotland over the last 25 years.
Methods
We conducted a consecutive retrospective individual patient linkage study across multiple national databases. Using data extracted from the Scottish hospital discharge dataset held by the Information Services Division of NHS National Services Scotland, we extracted episodes for all patients aged 20 years or older who were admitted with infective endocarditis between January 1, 1990, and December 31, 2014 in Scotland, UK. Patient episodes with infective endocarditis were linked to national prescribing and microbiology databases. The primary outcome was 1-year mortality following the index presentation. Generalised additive models were constructed to estimate the crude and age- and sex-stratified incidence rates (using a poison distribution) as well as trends in mortality (using a binomial distribution) adjusted for age, sex and comorbidity.
Results
Across 12,446 individual patients, there were a total of 12,667 hospitalisations (mean age 68±17 years, 55% females) with infective endocarditis using a 5-year look back period. The estimated crude rate of hospitalisation increased from 7.38 per 100,000 (95% CI 6.58 to 8.28) in 1990 to 15.09 per 100,000 (95% CI 13.90 to 16.39) in 2014 (p<0.001). Over the period of the study, 31% (3,877/12,667) of people admitted to hospital with infective endocarditis died within one year of admission. Case fatality fell markedly in both men and women from 1990 to 2014 (Figure). Microbiology was status was available for 34% of all hospitalisations with staphylococcus cultures associated with worse outcomes.
Conclusions
Despite the crude incidence of infective endocarditis doubling over the last 25 years and case fatality remaining high, the risk of death has markedly fallen over the last two decades. Staphylococcus cultures remain an independent marker of poor prognosis in this cohort.
Acknowledgement/Funding
British Heart Foundation
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Affiliation(s)
- A Shah
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | | | - F Astengo
- University of Edinburgh, Edinburgh, United Kingdom
| | - J Perez
- University of Glasgow, Glasgow, United Kingdom
| | - K K Lee
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - P Gallacher
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - J Hall
- University of Edinburgh, Edinburgh, United Kingdom
| | - R Bing
- University of Edinburgh, Edinburgh, United Kingdom
| | - A Anand
- University of Edinburgh, Edinburgh, United Kingdom
| | - D Newby
- University of Edinburgh, Edinburgh, United Kingdom
| | - N Mills
- University of Edinburgh, Edinburgh, United Kingdom
| | - N Cruden
- University of Edinburgh, Edinburgh, United Kingdom
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28
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Gallacher PJ, Miller-Hodges E, Shah A, Anand A, Lee KK, Chapman AR, Farrah T, Halbesma N, Blackmur J, Newby DE, Mills NL, Dhaun N. P1578Outcomes in patients with renal impairment and myocardial injury or infarction identified by high-sensitivity cardiac troponin testing: a secondary analysis of the High-STEACS trial. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Patients with renal impairment are at increased risk of myocardial infarction (MI), but the interpretation of cardiac troponin is challenging in this setting. The use of high-sensitivity cardiac troponin (hs-cTn) assays increases the detection of myocardial injury, yet may contribute to uncertainty in the diagnosis of MI in those with renal impairment.
Purpose
To describe the diagnosis and outcomes of patients with myocardial injury or infarction identified using a hs-cTnI assay, stratified by renal function.
Methods
In a pre-specified secondary analysis of a stepped-wedge cluster-randomised controlled trial, we identified consecutive patients with a hs-cTnI concentration greater than the sex-specific 99th centile between June 2013 and March 2016. The diagnoses of type 1 or type 2 MI were adjudicated and classified according to the 4th Universal Definition of Myocardial Infarction. Renal impairment was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73m2.The primary outcome of type 1 or type 4b MI or cardiovascular death was compared in patients with and without renal impairment at 1 year.
Results
A measure of renal function was available in 47,334 (98.0%) patients, of whom 7,933 (16.8%) had renal impairment (mean age 76±12 years; 54% female). Plasma hs-cTnI concentrations were >99th centile in 47.9% (3,800/7,933) of patients with renal impairment and 16.3% (6,439/39,401) of patients with normal renal function. In those with and without renal impairment, the adjudicated diagnosis was type 1 MI in 35.2% (1,336/3,800) and 55.8% (3,596/6,439) of patients, and type 2 MI in 12.6% (480/3,800) and 9.7% (626/6,439) of patients, respectively (P<0.001 for both). In patients with hs-cTnI concentrations >99th centile, the primary outcome occurred in 24.9% (945/3,800) of patients with renal impairment, compared to 12.1% (779/6,439) of patients with normal renal function (P<0.001). In patients with type 1 MI, the primary outcome occurred in 32.6% (436/1,336) of those with renal impairment and 11.7% (419/3,596) of those without (P<0.001). In patients with type 2 MI, the primary outcome occurred in 20.4% (98/480) and 9.9% (62/626) of patients with and without renal impairment, respectively (P<0.001).
Conclusion
Almost half of all patients with suspected acute coronary syndrome and renal impairment have hs-cTnI concentrations greater than the sex-specific 99th centile. Whilst only one in three had a diagnosis of type 1 MI, an elevated troponin concentration was associated with a poorer prognosis in those with concomitant renal impairment compared to those without, irrespective of the index diagnosis.
Acknowledgement/Funding
British Heart Foundation
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Affiliation(s)
- P J Gallacher
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - E Miller-Hodges
- Royal Infirmary of Edinburgh, Department of Renal Medicine, Edinburgh, United Kingdom
| | - A Shah
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A Anand
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - K K Lee
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A R Chapman
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - T Farrah
- Royal Infirmary of Edinburgh, Department of Renal Medicine, Edinburgh, United Kingdom
| | - N Halbesma
- University of Edinburgh, Edinburgh, United Kingdom
| | - J Blackmur
- University of Edinburgh, Edinburgh, United Kingdom
| | - D E Newby
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - N L Mills
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - N Dhaun
- Royal Infirmary of Edinburgh, Department of Renal Medicine, Edinburgh, United Kingdom
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Lee KK, Ferry AV, Anand A, Strachan FE, Chapman AR, Newby DB, Tuck C, Keerie C, Weir CJ, Shah ASV, Mills NL. P1731High-sensitivity troponin with sex-specific thresholds in suspected acute coronary syndrome. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background/Introduction
Major disparities between women and men in the diagnosis, management and outcome of acute coronary syndrome are well recognised. Whether sex-specific diagnostic thresholds for myocardial infarction will address these differences is uncertain.
Purpose
To evaluate the impact of implementing a high-sensitivity cardiac troponin I (hs-cTnI) assay with sex-specific diagnostic thresholds for myocardial infarction in women and men with suspected acute coronary syndrome.
Methods
In a stepped-wedge, cluster-randomized controlled trial across ten hospitals we evaluated the implementation of a hs-cTnI assay in 48,282 (47% women) consecutive patients with suspected acute coronary syndrome. During a validation phase the hs-cTnI assay results were suppressed and a contemporary cTnI assay with a single threshold was used to guide care. Myocardial injury was defined as any hs-cTnI concentration >99th centile of 16 ng/L in women and 34 ng/L in men. The primary outcome was myocardial infarction after the initial presentation or cardiovascular death at 1 year. In this prespecified analysis, we evaluated outcomes in men and women before and after implementation of the hs-cTnI assay.
Results
Use of the hs-cTnI assay with sex-specific thresholds increased myocardial injury in women by 42% (from 3,521 (16%) to 4,991 (22%)) and by 6% in men (from 5,068 (20%) to 5,369 (21%)). Whilst treatment increased in both sexes, women with myocardial injury remained less likely than men to undergo coronary revascularisation (15% versus34%), or to receive dual anti-platelet (26% versus43%), statin (16% versus26%) or other preventative therapies (P<0.001 for all). The primary outcome occurred in 18% (369/2,072) and 17% (488/2,919) of women with myocardial injury during the validation and implementation phase respectively (adjusted hazard ratio 1.11, 95% confidence interval 0.92 to 1.33), compared to 18% (370/2,044) and 15% (513/3,325) of men (adjusted hazard ratio 0.85, 95% confidence interval 0.71 to 1.01).
Patient management
Conclusion
Use of sex-specific thresholds identified five-times more additional women than men with myocardial injury, such that the proportion of women and men with myocardial injury is now similar. Despite this increase, women received approximately half the number of treatments for coronary artery disease as men and their outcomes were not improved.
Acknowledgement/Funding
The British Heart Foundation
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Affiliation(s)
- K K Lee
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A V Ferry
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A Anand
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - F E Strachan
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A R Chapman
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - D B Newby
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - C Tuck
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - C Keerie
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - C J Weir
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A S V Shah
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - N L Mills
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
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Anand A, Shah ASV, Strachan FE, Lee KK, Chapman AR, Bularga A, Stewart S, Ferry A, Marshall L, Newby DE, Mills NL. P3593Improving the performance of high-sensitivity cardiac troponin for the diagnosis of myocardial infarction. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz745.0453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
The Universal Definition of Myocardial Infarction (UDMI) mandates a rise and/or fall in high-sensitivity cardiac troponin (hs-cTn) concentration with at least one measure above the 99th centile of a healthy reference population. However, the 99th centile varies by age, sex, and prevalence of comorbid disease within reference populations, and the application of a single threshold may create diagnostic uncertainty in unselected patients attending the Emergency Department.
Purpose
To compare performance of hs-cTnI at the 99th centile with a model that includes additional clinical variables, for the diagnosis of type 1 myocardial infarction.
Methods
The High-Sensitivity Troponin in the Evaluation of patients with Acute Coronary Syndrome (High-STEACS trial) was a stepped wedge cluster randomised controlled trial of 48,282 consecutive patients across 10 hospitals in Scotland. We evaluated the positive predictive value (PPV) of a hs-cTnI >99th centile for a diagnosis of type 1 myocardial infarction. Patients with ST-segment elevation myocardial infarction (STEMI) were excluded, and all were adjudicated according to the 4th UDMI. The study population was randomly divided into derivation (80%) and internal validation (20%) cohorts. Using generalised additive modelling, we tested the effect of adding clinically relevant variables to hs-cTnI for the prediction of type 1 myocardial infarction in the derivation cohort, and assessed performance of the final model in the validation cohort.
Results
We included 47,101 consecutive patients (61±17 years, 47% female), of whom 9,057 (19%) had at least one hs-cTnI >99th centile (7,207 in derivation and 1,850 in validation cohorts). There were 4,087 (45%) patients with type 1 myocardial infarction, with 3239 (45%) and 848 (46%) in the derivation and validation cohorts, respectively. Across the study population, PPV for type 1 myocardial infarction reduced markedly with increasing age (Figure). Age, sex, chest pain, ischaemia on the electrocardiogram, creatinine and rate of change of hs-cTnI were included in the model. Comorbidities (ischaemic heart disease, diabetes, stroke and hyperlipidaemia) did not improve model performance. In the validation cohort, the area under the curve (AUC) for type 1 myocardial infarction using the 99th centile alone was 0.72 (95% CI 0.70–0.74), whereas the AUC for the optimised model was 0.84 (95% CI 0.82–0.85) (p<0.001 by DeLong's test for difference, see Figure).
Figure 1
Conclusion
The diagnostic performance of the 99th centile for type 1 myocardial infarction is poor, particularly in older populations. A simple model including readily available clinical features improves diagnostic performance and with further external validation could support more individualised treatment decisions.
Acknowledgement/Funding
British Heart Foundation
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Affiliation(s)
- A Anand
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A S V Shah
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - F E Strachan
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - K K Lee
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A R Chapman
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A Bularga
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - S Stewart
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A Ferry
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - L Marshall
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - D E Newby
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - N L Mills
- University of Edinburgh, Centre for Cardiovascular Science, Edinburgh, United Kingdom
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Chapman AR, Adamson PD, Anand A, Shah ASV, Lee KK, Strachan FE, Ferry ASV, Sandeman DE, Berry C, Gray AJ, Tuck C, Fox KAA, Newby DE, Weir C, Mills NL. 249High-sensitivity cardiac troponin and the universal definition of myocardial infarction: a randomised controlled trial. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz747.0066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
The Universal Definition of Myocardial Infarction recommends the 99th centile diagnostic threshold using a high-sensitivity cardiac troponin (hs-cTn) assay and the classification of patients by the etiology of myocardial injury. Whether implementation of this definition improves risk stratification, treatment or outcomes is unknown.
Methods
In a stepped-wedge cluster randomized controlled trial, we implemented a high-sensitivity troponin assay and the recommendations of the Universal Definition in 48,282 consecutive patients with suspected acute coronary syndrome across ten hospitals. In a pre-specified secondary analysis, we compared the primary outcome of myocardial infarction or cardiovascular death, and secondary outcome of non-cardiovascular death at one year across diagnostic categories as per the Fourth Universal Definition. We applied competing risks methodology in all analyses, using a cumulative incidence function and determining the cause-specific hazard ratio (csHR) for competing outcomes.
Results
Cardiac troponin concentrations were elevated in 21.5% (10,360/48,282) of all trial participants. Implementation increased the diagnosis of type 1 myocardial infarction by 11% (510/4,471), type 2 myocardial infarction by 22% (205/916), acute myocardial injury by 36% (443/1,233) and chronic myocardial injury by 43% (389/898). The risk and rate of the primary outcome was highest in those with type 1 myocardial infarction, whereas the risk and rate of non-cardiovascular death was highest in those with acute myocardial injury (Table, Figure). Despite increases in anti-platelet therapy and coronary revascularization after implementation, the primary outcome was unchanged in patients with type 1 myocardial infarction (csHR 1.00, 95% CI 0.82 to 1.21), or in any other category.
Adjusted csHR for competing outcomes Myocardial infarction or cardiovascular death Non-cardiovascular death Adjusted csHR (95% CI) Adjusted csHR (95% CI) Type 1 myocardial infarction 5.64 (5.12 to 6.22) 0.83 (0.72 to 0.96) Type 2 myocardial infarction 3.50 (2.94 to 4.15) 1.72 (1.44 to 2.06) Acute myocardial injury 4.38 (3.80 to 5.05) 2.65 (2.33 to 3.00) Chronic myocardial injury 3.88 (3.31 to 4.55) 2.06 (1.77 to 2.40) Cox regression models adjusted for age, sex, diabetes, ischaemic heart disease, season, days since trial onset and site of recruitment (as a random effect).
Cumulative incidence and number at risk
Conclusions
Implementation of the recommendations of the Universal Definition identified patients with different risks of future cardiovascular and non-cardiovascular events, but did not improve outcomes. Greater understanding of the underlying mechanisms and effective strategies for the investigation and treatment of patients with myocardial injury and infarction are required if we are to improve outcomes.
Acknowledgement/Funding
British Heart Foundation
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Affiliation(s)
- A R Chapman
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - P D Adamson
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A Anand
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A S V Shah
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - K K Lee
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - F E Strachan
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A S V Ferry
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - D E Sandeman
- Victoria Hospital, Cardiology, Kirkcaldy, United Kingdom
| | - C Berry
- Cardiovascular Research Centre of Glasgow, Glasgow, United Kingdom
| | - A J Gray
- Royal Infirmary of Edinburgh, Department of Emergency Medicine, Edinburgh, United Kingdom
| | - C Tuck
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - K A A Fox
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - D E Newby
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - C Weir
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - N L Mills
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
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Tan K, Chow WS, Leung J, Ho A, Ozaki R, Kam G, Li J, Choi CH, Tsang MW, Chan N, Lee KK, Chan KW. Clinical considerations when adding a sodium-glucose co-transporter-2 inhibitor to insulin therapy in patients with diabetes mellitus. Hong Kong Med J 2019; 25:312-319. [PMID: 31416990 DOI: 10.12809/hkmj197802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- K Tan
- Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - W S Chow
- Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - J Leung
- Department of Integrated Medical Service, Ruttonjee and Tang Shiu Kin Hospitals, Hong Kong
| | - A Ho
- Department of Medicine and Geriatrics, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - R Ozaki
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - G Kam
- Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
| | - J Li
- Department of Medicine, Yan Chai Hospital, Tsuen Wan, Hong Kong
| | - C H Choi
- Department of Medicine, Queen Elizabeth Hospital, Jordan, Hong Kong
| | - M W Tsang
- Specialist in Endocrinology, Private Practice
| | - N Chan
- Specialist in Endocrinology, Private Practice
| | - K K Lee
- Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - K W Chan
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Laichikok, Hong Kong
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Koh EH, Kaown D, Kim HJ, Lee KK, Kim H, Park S. Nationwide groundwater monitoring around infectious-disease-caused livestock mortality burials in Korea: Superimposed influence of animal leachate on pre-existing anthropogenic pollution. Environ Int 2019; 129:376-388. [PMID: 31150979 DOI: 10.1016/j.envint.2019.04.073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 03/28/2019] [Accepted: 04/30/2019] [Indexed: 06/09/2023]
Abstract
A foot-and-mouth disease (FMD) outbreak during 2010 affected the entire country of South Korea and approximately 3.4 million swine and bovine mortalities were disposed of at approximately 4800 on-farm burial sites for a few months following the first outbreak. Furthermore, outbreaks of avian influenza (AI) have struck Korea consistently since 2014. Public concern regarding the deterioration of the surrounding environment has been raised aiming at the enormous infected animal carcass burials. On behalf of the Ministry of Environment (ME) of the Korean government, we conducted groundwater monitoring at approximately 3000 wells around the burial sites for 7 years from 2011 to 2017. The baseline groundwater already had enriched levels of nitrogen and chloride compounds masking the influence of leachate with the pre-existing anthropogenic contamination. Based on the trend analysis, most monitoring wells had no significant trends in NO3-N and Cl implying that an abrupt degradation in water quality was not expected across the country. Increasing proportions of total coliform detection in the groundwater of the majority of provinces will cause potential damage to human health around the carcass burial sites. Wells showing frequent upward and downward trends near the carcass burial pits were targeted for principal component analysis (PCA) and the results showed that NH4-N, TOC, Cl, and K could be indicators distinguishing the sole impacts of animal leachate on the groundwater. Analyses of the nationwide monitoring data indicated possibly delayed and prolonged impacts of the widespread burials of livestock mortalities on the groundwater environment. The finding provides realistic insight regarding how to manage the mass burial of livestock mortalities to protect groundwater resources.
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Affiliation(s)
- Eun-Hee Koh
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyun Jung Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
| | - Hyunkoo Kim
- National Institute of Environmental Research, Incheon 22689, Republic of Korea
| | - Sunhwa Park
- National Institute of Environmental Research, Incheon 22689, Republic of Korea
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Joun WT, Rossabi J, Shin WJ, Lee KK. Real-time multi-level CO 2 concentration monitoring in vadose zone wells and the implication for detecting leakage events. J Environ Manage 2019; 237:534-544. [PMID: 30825786 DOI: 10.1016/j.jenvman.2019.01.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/08/2019] [Accepted: 01/16/2019] [Indexed: 06/09/2023]
Abstract
Multi-level wells screened at different depths in the vadose zone were installed and used for CO2 and carbon isotope monitoring. Well CO2 time series data were collected along with subsurface and atmospheric parameters such as air pressure, temperature, wind speed, and moisture content. Our aim was to determine the natural factors affecting the variation of CO2 concentration and how the influence of these factors varies with time of day and seasons of the year. We were motivated to understand the cause and extent of CO2 natural fluctuations in vadose zone wells in order to separate natural variation from signals due to anthropogenic CO2 leaks anticipating future monitoring using these wells. Variations of seasonal mean and variance of CO2 concentrations at different depths seem to follow the diurnal trend of subsurface temperature changes that reflect the atmospheric temperature but with time delay and amplitude damping due to heat transport considerations. The temperature in the ground lags behind the change in the atmospheric temperature, thus, the deeper the depth, the longer the time delay and the smaller the amplitude of the change. Monitored seasonal variation as shown in Appendix A shows the temperature-dependent depth-dependent CO2 production in the soil zone indicating higher CO2 concentrations in the summer and fall seasons with high concentrations ranging between 10,990 and 51,600 ppm from spring to summer, and 40,100 and 17,760 ppm from fall to winter. As the temperature in the organic-rich topsoil layer changes from daytime to nighttime, the concentration of CO2 in the soils also changes dynamically in response to chemical and biological reactions. When a screened well is installed in the vadose zone the dynamic temporal and depth difference in CO2 production is further complicated by upward (out of the subsurface) or downward (into the subsurface) gas flow, which will amplify or attenuate the temporal and vertical biochemically produced differences. Nested wells screened at different depths in the vadose zone and wells fully screened through the vadose zone were used for comparison. In addition, experiments changing the well from open to surface air to sealed at the top were conducted. The flow rates of inhaled (downward) and exhaled (upward) gas were estimated based on multi-level monitoring data. Based on time-series monitoring data, we proposed a time-dependent conceptual model to explain the changes of CO2 concentration in wells. The conceptual model was tested through analytical model computations. This conceptual model of natural variation of CO2 will be helpful in utilizing the vadose zone well as a method for monitoring CO2 leakage from subsurface storage or anthropogenic CO2 -producing activities.
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Affiliation(s)
- Won-Tak Joun
- School of Earth and Environmental Sciences, Seoul National Univ., Seoul, 151-747, South Korea
| | | | - Woo-Jin Shin
- Division of Earth and Environmental Sciences, Ochang Center, Korea Basic Science Institute, South Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National Univ., Seoul, 151-747, South Korea.
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Burford C, Cheng A, Jayne M, Alexander EC, Hall J, Lee KK, Patel AS. 42THE IMPACT OF DEMENTIA ON MORTALITY IN ACUTE MEDICAL ADMISSIONS. Age Ageing 2018. [DOI: 10.1093/ageing/afy121.07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- C Burford
- Faculty of Life Sciences and Medicine, King’s College London
| | - A Cheng
- Faculty of Life Sciences and Medicine, King’s College London
| | - M Jayne
- Faculty of Life Sciences and Medicine, King’s College London
| | - E C Alexander
- Faculty of Life Sciences and Medicine, King’s College London
| | - J Hall
- King’s College Hospital, London, UK
| | - K K Lee
- King’s College Hospital, London, UK
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Cheng A, Alexander EC, Burford C, Jayne M, Hall J, Patel AS, Lee KK. 40THE RELATIONSHIP BETWEEN LIVING ARRANGEMENT, CARE PACKAGES AND INPATIENT DEATHS IN OLDER ADULTS: A RETROSPECTIVE STUDY AT A LONDON TEACHING HOSPITAL. Age Ageing 2018. [DOI: 10.1093/ageing/afy121.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- A Cheng
- Faculty of Life Sciences and Medicine, King’s College London
| | - E C Alexander
- Faculty of Life Sciences and Medicine, King’s College London
| | - C Burford
- Faculty of Life Sciences and Medicine, King’s College London
| | - M Jayne
- Faculty of Life Sciences and Medicine, King’s College London
| | - J Hall
- King’s College Hospital, London, UK
| | | | - K K Lee
- King’s College Hospital, London, UK
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Chapman AR, Hesse K, Andrews JPM, Lee KK, Anand A, Ferry A, Stewart S, Marshall L, Strachan FE, Shah AS, Newby DE, Mills NL. 1085High-sensitivity cardiac troponin I and clinical risk scores in patients with suspected acute coronary syndrome. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.1085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A R Chapman
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - K Hesse
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - J P M Andrews
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - K K Lee
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A Anand
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A Ferry
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - S Stewart
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - L Marshall
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - F E Strachan
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - A S Shah
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - D E Newby
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
| | - N L Mills
- University of Edinburgh, BHF Centre for Cardiovascular Science, Edinburgh, United Kingdom
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Kim H, Kaown D, Mayer B, Lee JY, Lee KK. Combining pyrosequencing and isotopic approaches to assess denitrification in a hyporheic zone. Sci Total Environ 2018; 631-632:755-764. [PMID: 29544179 DOI: 10.1016/j.scitotenv.2018.03.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/07/2018] [Accepted: 03/07/2018] [Indexed: 06/08/2023]
Abstract
Hyporheic zones are considered hot spots for numerically vast and phylogenetically diverse microbial communities. However, biogeochemical effects of hyporheic zones have rarely been investigated in detail because of the difficulty in accurately measuring denitrification in these zones. To date, little is known about the hydroecology of hyporheic zones. The effect of changes in hydraulic conditions on the community variations of indigenous microorganisms and water quality was examined based on the depth of the hyporheic zone. In particular, we report on the use of the pyrosequencing technique to elucidate denitrifying bacteria (DNB) community profiles combined with the stable isotope composition of nitrate and hydrological patterns in the hyporheic zones to reveal whether denitrification occurs. δ15N-NO3 and δ18O-NO3 values of nitrate were analyzed to evaluate the transformation processes of nitrate in upwelling and downwelling areas and mixed zones. The isotope values indicated different origins of water in upwelling and downwelling zones and that denitrification occurred predominantly in the upwelling areas. Analyses of microbial communities in the hyporheic zone showed that the new genera, species, and isotope data were associated with the hydrological uniqueness of the hyporheic zones. The 16S rRNA sequences were determined and phylogenetic analysis revealed that the DNB communities distributed and gathered the genus Comamonas denitrificans within the mixing patterns of the hyporheic zones and that the relative scarcity of these microbes in these zones was caused by the lack of appropriate substrates. The delineation of the surface water-groundwater mixing zone was quantitatively determined by systematically combining the hydrological and heat transfer analyses and by comparing denitrifying bacteria communities and N isotope data. This study showed that pyrosequencing and isotopic approaches are useful for evaluating the transformation processes of nitrate at the upwelling and downwelling points of a hyporheic zone.
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Affiliation(s)
- Heejung Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
| | - Bernhard Mayer
- Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada
| | - Jin-Yong Lee
- Department of Geology, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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Cho PSP, Rainey A, Mukherjee B, Lee KK. P70 CPAP compliance in bariatric patients with obstructive sleep apnoea. Thorax 2016. [DOI: 10.1136/thoraxjnl-2016-209333.213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Kim YG, Kim SY, Kim JH, Lee KK, Yun YM. Prevalence and Clinical Relevance of Exon 2 Deletion of COMMD1 in Bedlington Terriers in Korea. J Vet Intern Med 2016; 30:1846-1850. [PMID: 27727471 PMCID: PMC5115198 DOI: 10.1111/jvim.14590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 07/28/2016] [Accepted: 08/31/2016] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Deletion of exon 2 of copper metabolism domain containing 1 (COMMD1) results in copper toxicosis in Bedlington terriers (CT-BT). OBJECTIVES This study was conducted to identify the prevalence and clinical relevance of the COMMD1 mutation in Bedlington terriers in Korea. ANIMALS A total of 105 purebred Bedlington terriers (50 males, 55 females) from the kennels and pet dog clubs in Korea were examined during the period 2008-2013. METHODS A multiplex PCR was carried out to detect exon 2 deletion of COMMD1. Clinical analysis was performed on each genetic group, and clinical status of the dogs was followed up to estimate survival probability. RESULTS Of the 105 samples, 52 (49%) were wild-type homozygote, 47 (45%) were heterozygote, and 6 (6%) were mutant-type homozygote. Plasma alanine aminotransferase (ALT) activity was increased in the mutant-type homozygous group >2 years of age (P < .0001). The survival probability of 6 mutant-type homozygotes surviving 2.5 years was 0.67, and 4 years was 0.5. CONCLUSIONS AND CLINICAL IMPORTANCE Results show the prevalence and clinical relevance of exon 2 deletion of COMMD1 and could help establish a structured selective breeding program to prevent CT-BT in Korea.
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Affiliation(s)
- Y G Kim
- Department of Internal Medicine, College of Veterinary Medicine, Jeju National University, Jeju, Korea
| | - S Y Kim
- Department of Internal Medicine, College of Veterinary Medicine, Jeju National University, Jeju, Korea
| | - J H Kim
- Department of Internal Medicine, College of Veterinary Medicine, Jeju National University, Jeju, Korea.,Veterinary Medical Research Institute, Jeju National University, Jeju, Korea
| | - K K Lee
- Department of Internal Medicine, College of Veterinary Medicine, Jeju National University, Jeju, Korea.,Veterinary Medical Research Institute, Jeju National University, Jeju, Korea
| | - Y M Yun
- Department of Internal Medicine, College of Veterinary Medicine, Jeju National University, Jeju, Korea.,Veterinary Medical Research Institute, Jeju National University, Jeju, Korea
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Lee SS, Kaown D, Lee KK. Evaluation of the fate and transport of chlorinated ethenes in a complex groundwater system discharging to a stream in Wonju, Korea. J Contam Hydrol 2015; 182:231-243. [PMID: 26433603 DOI: 10.1016/j.jconhyd.2015.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 08/27/2015] [Accepted: 09/10/2015] [Indexed: 06/05/2023]
Abstract
Chlorinated ethenes such as trichloroethylene (TCE) are common and persistent groundwater contaminants. If contaminated groundwater discharges to a stream, then stream water pollution near the contamination site also becomes a problem. In this respect, the fate and transport of chlorinated ethenes around a stream in an industrial complex were evaluated using the concentration of each component, and hydrogeochemical, microbial, and compound-specific carbon isotope data. Temporal and spatial monitoring reveal that a TCE plume originating from main and local source zones continues to be discharged to a stream. Groundwater geochemical data indicate that aerobic conditions prevail in the upgradient area of the studied aquifer, whereas conditions become anaerobic in the downgradient. The TCE molar fraction is high at the main and local source zones, ranging from 87.4 to 99.2% of the total volatile organic compounds (VOCs). An increasing trend in the molar fraction of cis-1, 2-Dichloroethene (cis-DCE) and vinyl chloride (VC) was observed in the downgradient zone of the study area. The enriched δ(13)C values of TCE and depleted values of cis-DCE in the stream zone, compared to those of the source zone, also suggest biodegradation of VOCs. Microbial community structures in monitoring wells adjacent to the stream zone in the downgradient area were analyzed using 16S rRNA gene-based pyrosequencing to identify the microorganisms responsible for biodegradation. This was attributed to the high relative abundance of dechlorinating bacteria in monitoring wells under anaerobic conditions farthest from the stream in the downgradient area. The multilateral approaches adopted in this study, combining hydrogeochemical and biomolecular methods with compound-specific analyses, indicate that contaminants around the stream were naturally attenuated by active anaerobic biotransformation processes.
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Affiliation(s)
- Seong-Sun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea.
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Kaown D, Shouakar-Stash O, Yang J, Hyun Y, Lee KK. Identification of multiple sources of groundwater contamination by dual isotopes. Ground Water 2014; 52:875-885. [PMID: 24164437 DOI: 10.1111/gwat.12130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Accepted: 09/11/2013] [Indexed: 06/02/2023]
Abstract
Chlorinated solvents are one of the most commonly detected groundwater contaminants in industrial areas. Identification of polluters and allocation of contaminant sources are important concerns in the evaluation of complex subsurface contamination with multiple sources. In recent years, compound-specific isotope analyses (CSIA) have been employed to discriminate among different contaminant sources and to better understand the fate of contaminants in field-site studies. In this study, the usefulness of dual isotopes (carbon and chlorine) was shown in assessments of groundwater contamination at an industrial complex in Wonju, Korea, where groundwater contamination with chlorinated solvents such as trichloroethene (TCE) and carbon tetrachloride (CT) was observed. In November 2009, the detected TCE concentrations at the study site ranged between nondetected and 10,066 µg/L, and the CT concentrations ranged between nondetected and 985 µg/L. In the upgradient area, TCE and CT metabolites were detected, whereas only TCE metabolites were detected in the downgradient area. The study revealed the presence of separate small but concentrated TCE pockets in the downgradient area, suggesting the possibility of multiple contaminant sources that created multiple comingling plumes. Furthermore, the variation of the isotopic (δ(13) C and δ(37) Cl) TCE values between the upgradient and downgradient areas lends support to the idea of multiple contamination sources even in the presence of detectable biodegradation. This case study found it useful to apply a spatial distribution of contaminants coupled with their dual isotopic values for evaluation of the contaminated sites and identification of the presence of multiple sources in the study area.
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Affiliation(s)
- Dugin Kaown
- School of Earth and Environmental Sciences (BK21 SEES), Seoul National University, Seoul 151-747, Korea
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Park DK, Bae GO, Kim SK, Lee KK. Groundwater pumping effects on contaminant loading management in agricultural regions. J Environ Manage 2014; 139:97-108. [PMID: 24681649 DOI: 10.1016/j.jenvman.2014.02.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 02/03/2014] [Accepted: 02/17/2014] [Indexed: 06/03/2023]
Abstract
Groundwater pumping changes the behavior of subsurface water, including the location of the water table and characteristics of the flow system, and eventually affects the fate of contaminants, such as nitrate from agricultural fertilizers. The objectives of this study were to demonstrate the importance of considering the existing pumping conditions for contaminant loading management and to develop a management model to obtain a contaminant loading design more appropriate and practical for agricultural regions where groundwater pumping is common. Results from this study found that optimal designs for contaminant loading could be determined differently when the existing pumping conditions were considered. This study also showed that prediction of contamination and contaminant loading management without considering pumping activities might be unrealistic. Motivated by these results, a management model optimizing the permissible on-ground contaminant loading mass together with pumping rates was developed and applied to field investigation and monitoring data from Icheon, Korea. The analytical solution for 1-D unsaturated solute transport was integrated with the 3-D saturated solute transport model in order to approximate the fate of contaminants loaded periodically from on-ground sources. This model was further expanded to manage agricultural contaminant loading in regions where groundwater extraction tends to be concentrated in a specific period of time, such as during the rice-growing season, using a method that approximates contaminant leaching to a fluctuating water table. The results illustrated that the simultaneous management of groundwater quantity and quality was effective and appropriate to the agricultural contaminant loading management and the model developed in this study, which can consider time-variant pumping, could be used to accurately estimate and to reasonably manage contaminant loading in agricultural areas.
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Affiliation(s)
- Dong Kyu Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Republic of Korea
| | - Gwang-Ok Bae
- School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Republic of Korea
| | - Seong-Kyun Kim
- Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Republic of Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Republic of Korea.
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Cheung E, Bow C, Loong C, Lee KK, Ho AYY, Soong C, Chan YY, Tan KCB, Kung AWC. A secular increase in BMD in Chinese women. J Bone Miner Metab 2014; 32:48-55. [PMID: 23636506 DOI: 10.1007/s00774-013-0463-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 03/19/2013] [Indexed: 02/04/2023]
Abstract
Population-based studies have revealed a decline in the incidence of age-adjusted hip fractures in southern Chinese women during the past decade. To determine whether there was a secular change in population characteristics that accounted for this decline, we compared the bone mineral density (BMD) and lifestyle habits of two cohorts of women who were more than 50 years of age and who were recruited from 1995 to 2000 and 2005 to 2010. The BMD levels in the 2005-2010 cohort were significantly higher at the spine and hip and ranged from 3.6 to 17.8% among the different age groups. Additionally, a significantly lower prevalence of subjects with osteoporosis and osteopenia was observed. Longer reproductive years, higher levels of physical activity, higher estradiol and 25(OH) vitamin D levels, and lower alkaline phosphatase levels were found in the 2005-2010 cohort. After adjusting for bone-determining factors, significant differences were detected in the BMD levels at the lumbar spine, femoral neck, and total hip (4.17, 9.02, and 9.34%, respectively) in women >50 years of age but not in women ≤50 years of age. The secular increase in BMD and healthier lifestyles most likely led to the decline in the incidence of age-adjusted fractures.
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Affiliation(s)
- Elaine Cheung
- Department of Medicine, The University of Hong Kong and Queen Mary Hospital, Hospital Authority, Hong Kong, China
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Lee SS, Kim HM, Lee SH, Yang JH, Koh YE, Lee KK. Evidences of in Situ Remediation from Long Term Monitoring Data at a TCE-contaminated Site, Wonju, Korea. ACTA ACUST UNITED AC 2013. [DOI: 10.7857/jsge.2013.18.6.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ruickbie SV, Kursumovic E, Narayan B, Opong K, Luce P, Toma T, Baker LV, Lee KK. P13 Mismatch Between Clinical and Radiological Diagnosis of Pneumonia: Abstract P13 Table 1. Thorax 2012. [DOI: 10.1136/thoraxjnl-2012-202678.154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Lee KK, Ward K, Raywood E, Moxham J, Rafferty GF, Birring SS. P161 Cough Intensity in Voluntary, Induced and Spontaneous Cough: Abstract P161 Table 1. Thorax 2012. [DOI: 10.1136/thoraxjnl-2012-202678.222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Lee KK, Ward K, Raywood E, Moxham J, Rafferty GF, Birring SS. P160 Increased cough intensity in patients with chronic cough: Abstract P160 Table 1. Thorax 2012. [DOI: 10.1136/thoraxjnl-2012-202678.221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Lee KK, Matos S, Ward K, Raywood E, Evans DH, Moxham J, Rafferty GF, Birring SS. P158 Cough Sound Intensity: The Development of a Novel Measure of Cough Severity: Abstract P158 Table 1. Thorax 2012. [DOI: 10.1136/thoraxjnl-2012-202678.219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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