1
|
Nguyen DH, Liao CH, Bui XT, Wang LC, Yuan CS, Lin C. Deseasonalized trend of ground-level ozone and its precursors in an industrial city Kaohsiung, Taiwan. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 351:124036. [PMID: 38677459 DOI: 10.1016/j.envpol.2024.124036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 04/17/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
Mitigating ground-level ozone (GLO) remains challenging due to its highly nonlinear formation process. Thus, understanding GLO pollution trends is crucial for developing effective control strategies, especially Kaohsiung industrial city, Taiwan. Based on the long-term monitoring data set of 2011-2022, temporal analysis reveals that monthly mean GLO peaks in autumn (40.66 ± 5.10 ppb), carbon monoxide (CO) and major precursors such as nitrogen oxides (NOx), nonmethane hydrocarbons (NMHC) reach their highest levels in winter. The distinct seasonal variation of air pollutants in Kaohsiung is primarily influenced by the unique blocking effect of the mountainous area under the northeasterly wind, as the city is situated downwind, causing high GLO levels during autumn due to the accumulation of stagnant air hindering the dispersion of pollutants. Over the 12 years (2011-2022), the deseasonalized trend analysis was conducted with p < 0.001, revealing a stabilization trend of GLO (+0.04 ppb/yr) from a previous sharp increase. The observed improvement is credited to a drastic decrease in total oxidants (Ox) at -0.63 ppb/yr due to significantly reducing their precursors. Furthermore, the effectiveness of precursor reduction is also supported by GLO daily maximum profile changes. While high GLO events (>120 ppb) decrease, days within midrange (60-80 ppb) rise from 24.4% to 33.3%. A notable difference emerges when comparing daytime and nighttime GLO. While daytime GLO decreased at -0.22 ppb/yr, nighttime GLO increased at +0.34 ppb/yr. Weakened nocturnal titration effects accounted for the nighttime increase. The distinct spatial variations in GLO trends on a citywide scale underscore that areas with complicated industrial activities may not benefit from a continuing reduction of precursors compared to less-polluted areas. The findings of this study hold significant implications for improving GLO control strategies in heavily industrialized city and provide valuable information to the general public about the current state of GLO pollution.
Collapse
Affiliation(s)
- Duy-Hieu Nguyen
- Program in Maritime Science and Technology, College of Maritime, National Kaohsiung University of Science and Technology, Kaohsiung, 811213, Taiwan
| | - Chih-Hsiang Liao
- Department of Environmental Engineering and Science, Chia-Nan University of Pharmacy and Science, Tainan, 71710, Taiwan
| | - Xuan-Thanh Bui
- Key Laboratory of Advanced Waste Treatment Technology & Faculty of Environment and Natural Resources, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, 700000, Viet Nam; Vietnam National University Ho Chi Minh City (VNU-HCM), Linh Trung ward, Ho Chi Minh City, 700000, Viet Nam
| | - Lin-Chi Wang
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, 811213, Taiwan
| | - Chung-Shin Yuan
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan
| | - Chitsan Lin
- Program in Maritime Science and Technology, College of Maritime, National Kaohsiung University of Science and Technology, Kaohsiung, 811213, Taiwan; Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, 811213, Taiwan.
| |
Collapse
|
2
|
Nguyen QV, Liou YA. Greenspace pattern, meteorology and air pollutant in Taiwan: A multifaceted connection. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169883. [PMID: 38185171 DOI: 10.1016/j.scitotenv.2024.169883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 12/28/2023] [Accepted: 01/01/2024] [Indexed: 01/09/2024]
Abstract
Air pollution is a global environmental concern that poses a significant threat to human health. Given the impact of urbanization and climate change, green planning is being encouraged to improve air quality. The study aims to examine the intricate relationships between greenspace pattern and outdoor air around 73 in-situ stations over Taiwan during the dry (November to April) and wet (May to December) seasons from 2015 to 2020. To achieve this, Partial Least Squares - Structural Equation Modeling was utilized to analyze the interactions among seven dimensions: greenspace - GS, gaseous pollutant - GP, particle pollutant - PP, O3 - OZONE, air temperature - TEMP, relative humidity - RH, and wind speed - WS. The GS involves seven landscape metrics: edge density, total edge, effective mesh size, largest patch area, percentage of landscape, total core area, and patch cohesion index. The results indicate that the GS has a stronger effect on the GP, whereas its effect on the PP is weaker during the dry season compared to the wet season. While its effect on the TEMP is weaker, it shows a slightly stronger effect on the RH during the dry season. Moreover, the GS mediates the air pollutant dimensions during the two seasons, with the RH acting as a primary mediator. The meteorological dimensions primarily have a greater influence on the air pollutant dimensions during the dry season than the wet season. Consequently, the GS explains 11.3 % more and 18.4 % less of the variances in the RH and TEMP during the dry season, respectively. Moreover, the GS and meteorological dimensions yield a seasonal difference in explained variance, with the highest value observed for the OZONE (R2 = 24.2 %), followed by the PP (R2 = 9.7 %) and GP (R2 = 7.7 %). Notably, seven landscape metrics serve as potential indicators for green strategies in urban planning to enhance outdoor air quality.
Collapse
Affiliation(s)
- Quang-Viet Nguyen
- Faculty of Geography and Geology, University of Sciences, Hue University, 77-Nguyen Hue, Hue 530000, Viet Nam.
| | - Yuei-An Liou
- Center for Space and Remote Sensing Research, National Central University, No. 300, Jhongda Rd., Jhongli District, Taoyuan City 320317, Taiwan, ROC.
| |
Collapse
|
3
|
Lee CH, Brimblecombe P, Lee CL. Fifty-year change in air pollution in Kaohsiung, Taiwan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:84521-84531. [PMID: 35781652 PMCID: PMC9646597 DOI: 10.1007/s11356-022-21756-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 06/26/2022] [Indexed: 06/15/2023]
Abstract
The change in air quality in cities can be the product of regulation and emissions. Regulations require enforcement of emission reduction, but it is often shifting economic and societal structures that influence pollutant emissions. This study examines the long-term record of air pollutants in Kaohsiung, where post-war industrialisation increased pollution substantially, although improvements are observed in recent decades as the city moved to a more mixed economy. The study tracks both gases and particles across a period of significant change in pollution sources in the city. Concentrations of SO2 and aerosol SO42- were especially high ~1970, but these gradually declined, although SO42- to a lesser extent than its precursor, SO2. While twenty-first century emissions of SO2 and NOx have declined, this has been less so for NH3, because it arises from predominantly agricultural sources. The atmosphere in Kaohsiung continues to have high concentrations of O3, and these have risen in the city, likely a product of less titration by NO. The changes have meant that ozone has become an increasing threat to health and agriculture. Despite a potential for producing (NH4)2SO4 and NH4NO3 aerosols, a product of a relatively constant supply of NH3, visibility has improved in recent years. Emissions of SO2 and NOx should continue to be reduced, as these strongly affect the amount of fine secondary aerosol. However, the key problem may be ozone, which is difficult to control as it requires careful consideration of the balance of NOx and hydrocarbons so important to its production.
Collapse
Affiliation(s)
- Chiu-Hsuan Lee
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Peter Brimblecombe
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan.
| | - Chon-Lin Lee
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
- Aerosol Science and Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan
- Department of Public Health, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Applied Chemistry, Providence University, Taichung, Taiwan
| |
Collapse
|
4
|
Hsu CY, Chang YT, Lin CJ. How a winding-down oil refinery park impacts air quality nearby? ENVIRONMENT INTERNATIONAL 2022; 169:107533. [PMID: 36150296 DOI: 10.1016/j.envint.2022.107533] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/12/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
It is always difficult to compare, let alone estimate, the difference of air pollutant concentrations before and after closure of a major source because the pollutants cannot be traced or predicted after entering the ambient. Indeed, we are not aware of any studies specifically related to the air pollutants impacted by a winding-down source. In this work, we applied nine years (2010-2018) online measurement of air pollutants (including PM10, PM2.5, NO2, SO2, O3 and VOCs) to investigate (i) the temporal behavior of air pollutants before and after closure of an oil refinery park by using pair-wise statistics and correlations between wind speed and direction, and (ii) the source impacts on O3 concentrations using PMF coupled with multiple linear regression (MLR) analysis (PMF-MLR). Example applications are presented at two monitoring sites (A and B) close to the Kaohsiung Oil Refinery (KOR), located in the southern industrial city of Taiwan. The results show that the KOR shutdown changed air pollutant concentrations to a certain extent in these study areas. We also conclude that, instead of using propylene-equivalent and ozone formation potential (OFP) concentrations, it is better to estimate the formation of O3 based on PMF-MLR analysis as developed in this study. The PMF analysis has identified various VOCs sources at both sites including solvent usage, petrochemical industrial sources, industrial emissions, vehicle-related sources, vegetation emissions and aged air-masses. Also, the MLR model shows that both the background sources and petrochemical industrial sources may significantly change O3 concentrations.
Collapse
Affiliation(s)
- Chin-Yu Hsu
- Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist, New Taipei City 24301, Taiwan; Center for Environmental Sustainability and Human Health, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist, New Taipei City 24301, Taiwan.
| | - Yu-Tzu Chang
- Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist, New Taipei City 24301, Taiwan
| | - Cheng-Ju Lin
- Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist, New Taipei City 24301, Taiwan
| |
Collapse
|
5
|
Hsu CY, Xie HX, Wong PY, Chen YC, Chen PC, Wu CD. A mixed spatial prediction model in estimating spatiotemporal variations in benzene concentrations in Taiwan. CHEMOSPHERE 2022; 301:134758. [PMID: 35490755 DOI: 10.1016/j.chemosphere.2022.134758] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 04/12/2022] [Accepted: 04/25/2022] [Indexed: 06/14/2023]
Abstract
It is well known benzene negatively impacts human health. This study is the first to predict spatial-temporal variations in benzene concentrations for the entirety of Taiwan by using a mixed spatial prediction model integrating multiple machine learning algorithms and predictor variables selected by Land-use Regression (LUR). Monthly benzene concentrations from 2003 to 2019 were utilized for model development, and monthly benzene concentration data from 2020, as well as mobile monitoring vehicle data from 2009 to 2019, served as external data for verifying model reliability. Benzene concentrations were estimated by running six LUR-based machine learning algorithms; these algorithms, which include random forest (RF), deep neural network (DNN), gradient boosting (GBoost), light gradient boosting (LightGBM), CatBoost, extreme gradient boosting (XGBoost), and ensemble algorithms (a combination of the three best performing models), can capture how nonlinear observations and predictions are related. The results indicated conventional LUR captured 79% of the variability in benzene concentrations. Notably, the LUR with ensemble algorithm (GBoost, CatBoost, and XGBoost) surpassed all other integrated methods, increasing the explanatory power to 92%. This study establishes the value of the proposed ensemble-based model for estimating spatiotemporal variation in benzene exposure.
Collapse
Affiliation(s)
- Chin-Yu Hsu
- Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, Taiwan; Center for Environmental Sustainability and Human Health, Ming Chi University of Technology, Taiwan
| | - Hong-Xin Xie
- Department of Geomatics, National Cheng Kung University, Tainan, Taiwan
| | - Pei-Yi Wong
- Department of Environmental and Occupational Health, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Cheng Chen
- National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan; Department of Occupational Safety and Health, China Medical University, Taichung, Taiwan
| | - Pau-Chung Chen
- National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan; Institute of Environmental and Occupational Health Sciences, National Taiwan University College of Public Health, Taipei, Taiwan; Department of Environmental and Occupational Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Public Health, National Taiwan University College of Public Health, Taipei, Taiwan
| | - Chih-Da Wu
- Department of Geomatics, National Cheng Kung University, Tainan, Taiwan; National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan.
| |
Collapse
|
6
|
Sharma GK, Tewani A, Gargava P. Comprehensive analysis of ambient air quality during second lockdown in national capital territory of Delhi. JOURNAL OF HAZARDOUS MATERIALS ADVANCES 2022; 6:100078. [PMID: 36919145 PMCID: PMC9427329 DOI: 10.1016/j.hazadv.2022.100078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/02/2022] [Accepted: 04/18/2022] [Indexed: 12/23/2022]
Abstract
The lockdown imposed in Delhi, due to the second wave of the COVID-19 pandemic has led to significant gains in air quality. Under the lockdown, restrictions were imposed on movement of people, operation of industrial establishments and hospitality sector amongst others. In the study, Air Quality Index and concentration trends of six pollutants, i.e. PM2.5, PM10, NO2, SO2, CO, and O3 were analysed for National Capital Territory of Delhi, India for three periods in 2021 (pre-lockdown: 15 March to 16 April 2021, lockdown: 17 April to 31 May 2021 and post-lockdown: 01 June to 30 June). Data for corresponding periods in 2018-2020 was also analysed. Lockdown period saw 6 days in satisfactory AQI category as against 0 days in the same category during the pre-lockdown period. Average PM2.5, PM10, NO2 and SO2 concentrations reduced by 22%, 31%, 25% and 28% respectively during lockdown phase as compared to pre-lockdown phase, while O3 was seen to increase. Variation in meteorological parameters and correlation of pollutants has also been examined. The significant improvement arising due to curtailment of certain activities in the lockdown period indicates the importance of local emission control, and helps improve the understanding of the dynamics of air pollution, thus highlighting policy areas to regulatory bodies for effective control of air pollution.
Collapse
Affiliation(s)
- Gautam Kumar Sharma
- Central Pollution Control Board, Parivesh Bhawan, East Arjun Nagar, Delhi 110032, India
| | - Ankush Tewani
- Central Pollution Control Board, Parivesh Bhawan, East Arjun Nagar, Delhi 110032, India
| | - Prashant Gargava
- Central Pollution Control Board, Parivesh Bhawan, East Arjun Nagar, Delhi 110032, India
| |
Collapse
|
7
|
Wong PY, Lee HY, Chen YC, Zeng YT, Chern YR, Chen NT, Candice Lung SC, Su HJ, Wu CD. Using a land use regression model with machine learning to estimate ground level PM 2.5. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 277:116846. [PMID: 33735646 DOI: 10.1016/j.envpol.2021.116846] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/30/2021] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
Ambient fine particulate matter (PM2.5) has been ranked as the sixth leading risk factor globally for death and disability. Modelling methods based on having access to a limited number of monitor stations are required for capturing PM2.5 spatial and temporal continuous variations with a sufficient resolution. This study utilized a land use regression (LUR) model with machine learning to assess the spatial-temporal variability of PM2.5. Daily average PM2.5 data was collected from 73 fixed air quality monitoring stations that belonged to the Taiwan EPA on the main island of Taiwan. Nearly 280,000 observations from 2006 to 2016 were used for the analysis. Several datasets were collected to determine spatial predictor variables, including the EPA environmental resources dataset, a meteorological dataset, a land-use inventory, a landmark dataset, a digital road network map, a digital terrain model, MODIS Normalized Difference Vegetation Index (NDVI) database, and a power plant distribution dataset. First, conventional LUR and Hybrid Kriging-LUR were utilized to identify the important predictor variables. Then, deep neural network, random forest, and XGBoost algorithms were used to fit the prediction model based on the variables selected by the LUR models. Data splitting, 10-fold cross validation, external data verification, and seasonal-based and county-based validation methods were used to verify the robustness of the developed models. The results demonstrated that the proposed conventional LUR and Hybrid Kriging-LUR models captured 58% and 89% of PM2.5 variations, respectively. When XGBoost algorithm was incorporated, the explanatory power of the models increased to 73% and 94%, respectively. The Hybrid Kriging-LUR with XGBoost algorithm outperformed the other integrated methods. This study demonstrates the value of combining Hybrid Kriging-LUR model and an XGBoost algorithm for estimating the spatial-temporal variability of PM2.5 exposures.
Collapse
Affiliation(s)
- Pei-Yi Wong
- Department of Environmental and Occupational Health, National Cheng Kung University, Tainan, Taiwan
| | - Hsiao-Yun Lee
- Department of Leisure Industry and Health Promotion, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan
| | - Yu-Cheng Chen
- National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan
| | - Yu-Ting Zeng
- Department of Geomatics, National Cheng Kung University, Tainan, Taiwan
| | - Yinq-Rong Chern
- Department of Geomatics, National Cheng Kung University, Tainan, Taiwan
| | - Nai-Tzu Chen
- Research Center of Environmental Trace Toxic Substances, National Cheng Kung University, Tainan, Taiwan
| | - Shih-Chun Candice Lung
- Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan; Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan; Institute of Environmental Health, National Taiwan University, Taipei, Taiwan
| | - Huey-Jen Su
- Department of Environmental and Occupational Health, National Cheng Kung University, Tainan, Taiwan
| | - Chih-Da Wu
- National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan; Department of Geomatics, National Cheng Kung University, Tainan, Taiwan.
| |
Collapse
|
8
|
Qu F, Liu F, Zhang H, Chao L, Guan J, Li R, Yu F, Yan X. Comparison of air pollutant-related hospitalization burden from AECOPD in Shijiazhuang, China, between heating and non-heating season. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:31225-31233. [PMID: 31463744 DOI: 10.1007/s11356-019-06242-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 08/16/2019] [Indexed: 06/10/2023]
Abstract
Few researches have been investigated on the effects of ambient air pollutants from coal combustion on acute exacerbation of chronic obstructive pulmonary disease (AECOPD) hospitalizations. The whole time series was split into heating season and non-heating season. We used a quasi-Poisson generalized linear regression model combined with distributed lag non-linear models (DLNMs) to estimate the relative cumulative risk and calculate the air pollutant hospitalization burden of AECOPD for lag 0-7 days in heating season and non-heating season. There were higher PM2.5, PM10, NO2, SO2, and CO concentrations in heating seasons than non-heating season in Shijiazhuang; however, O3 was higher in non-heating season than heating season. The AECOPD-associated relative cumulative risks for PM2.5, PM10, NO2, and SO2 for lag 0-7 days were significantly positively associated with hospitalization in heating and non-heating season; we found that the cumulative relative risk of NO2 was the greatest in every 1 unit of air pollutants during the heating season and the cumulative relative risk of SO2 was the greatest during the non-heating season. The results showed that 17.8%, 12.9%, 1.7%, 16.7%, and 10.5% of AECOPD hospitalizations could be attributable to PM2.5, PM10, SO2, NO2, and CO exposure in heating season, respectively. However, the results showed that 19.5%, 22.4%, 15%, 8.3%, and 10.4% of AECOPD hospitalizations could be attributable to PM2.5, PM10, SO2, NO2, and O3 exposure in non-heating season, respectively. The attributable burden of AECOPD hospitalization in heating season and non-heating season are different. PM2.5, PM10, NO2, and CO are the main factors of heating season, while PM10, PM2.5, SO2, and O3 are the main factors of non-heating season. In conclusions, the centralized heating can change the influence of attributable risk. When government departments formulate interventions to reduce the risk of acute hospitalization of chronic obstructive pulmonary disease (COPD), the influence of heating on disease burden should be considered.
Collapse
Affiliation(s)
- Fangfang Qu
- Department of Respiratory and Critical Care Medicine, The Second Hospital of HeBei Medical University, No. 215 Heping West Road, Shijiazhuang, Hebei Province, China
- HeBei institute of Respiratory Disease, Shijiazhuang, China
| | - Feifei Liu
- Department of Respiratory and Critical Care Medicine, The Second Hospital of HeBei Medical University, No. 215 Heping West Road, Shijiazhuang, Hebei Province, China
- HeBei institute of Respiratory Disease, Shijiazhuang, China
| | - Huiran Zhang
- Department of Respiratory and Critical Care Medicine, The Second Hospital of HeBei Medical University, No. 215 Heping West Road, Shijiazhuang, Hebei Province, China
- HeBei institute of Respiratory Disease, Shijiazhuang, China
| | - Lingshan Chao
- Department of Respiratory and Critical Care Medicine, The Second Hospital of HeBei Medical University, No. 215 Heping West Road, Shijiazhuang, Hebei Province, China
- HeBei institute of Respiratory Disease, Shijiazhuang, China
| | - Jitao Guan
- Department of Respiratory and Critical Care Medicine, The Second Hospital of HeBei Medical University, No. 215 Heping West Road, Shijiazhuang, Hebei Province, China
- HeBei institute of Respiratory Disease, Shijiazhuang, China
| | - Rongqin Li
- Department of Central Laboratory, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Fengxue Yu
- Department of Central Laboratory, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Xixin Yan
- Department of Respiratory and Critical Care Medicine, The Second Hospital of HeBei Medical University, No. 215 Heping West Road, Shijiazhuang, Hebei Province, China.
- HeBei institute of Respiratory Disease, Shijiazhuang, China.
| |
Collapse
|
9
|
Lee CS, Chang KH, Kim H. Long-term (2005-2015) trend analysis of PM 2.5 precursor gas NO 2 and SO 2 concentrations in Taiwan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:22136-22152. [PMID: 29802618 DOI: 10.1007/s11356-018-2273-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 05/08/2018] [Indexed: 06/08/2023]
Abstract
Ground air monitoring stations have been installed in Taiwan since 1993 to ensure whether the criteria air pollutants meet the ambient air quality standards. In the present study, the data from the monitoring stations were used to evaluate long-term (2005-2015) trend of NO2 and SO2 in three metropolitan cities (northern Taipei, central Taichung, and southern Kaohsiung), two eastern coastal cities (Hualien and Taitung), and one agricultural city in west-central plain (Douliu); those cities essentially covered the entire region of Taiwan. The results indicate that SO2 and NO2 concentrations of all studied six cities meet the annual average standards of 30 and 50 ppb, respectively. After deseasonalizing the original data and using 7-month moving average, the trend analysis reveals a decreasing trend ranging from 0.15 to 0.57 ppb/year (R2 from 0.33 to 0.85) for NO2 and 0.06 to 0.45 ppb/year (R2 from 0.32 to 0.92) for SO2; the corresponding reductions over the 10-year span are 4 to 42% for NO2 and 22 to 52% for SO2. The reduction trend, despite the growth in GDP, vehicle numbers and energy consumption, industrial output, etc., is similar to those of developed countries. Clearly, there are seasonal/monthly variation patterns for these two precursor gases with minimum levels in summer (July) and maximum in winter (December). The concentration reductions, however, were lagging behind the respective emission reductions. There are significant correlations among six cites for NO2 (r = 0.58-0.93) and, to some extent, SO2 (0.32-0.66). The correlation between SO2 and NO2 (r = 0.46-0.74) indicates same or similar emission sources. Furthermore, the correlation between observed pollutant concentrations and their emission is excellent for SO2 in two cities (0.79-0.96). The SO2/NO2 ratios vary with city and time and the value is site specific. For example, in 2005, the SO2/NO2 ratio was 0.38 in Kaohsiung and 0.18 in both Taipei and Taichung, the latter reflecting significant contribution from mobile sources. However, they all converged to 0.18-0.28 in 2015 in the six cities evaluated. All in all, the policies/measures made by the central and local government are effective in reducing ambient SO2 and NO2 levels.
Collapse
Affiliation(s)
- Chih-Sheng Lee
- Department of Environmental Engineering, Kun Shan University, Tainan, 71070, Taiwan
| | - Ken-Hui Chang
- Department of Safety, Health, and Environmental Engineering, National Yunlin University of Science and Technology, Yunlin, 64002, Taiwan.
| | - Hyunook Kim
- Department of Energy & Environmental System Engineering, The University of Seoul, Seoul, 02504, South Korea
| |
Collapse
|
10
|
Effects of Climate Change and Ozone Concentration on the Net Primary Productivity of Forests in South Korea. FORESTS 2018. [DOI: 10.3390/f9030112] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
11
|
Park HK. Air pollution and climate change: Effects on asthmatic patients. ALLERGY ASTHMA & RESPIRATORY DISEASE 2018. [DOI: 10.4168/aard.2018.6.2.79] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Hye-Kyung Park
- Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
| |
Collapse
|
12
|
Hwang SL, Guo SE, Chi MC, Chou CT, Lin YC, Lin CM, Chou YL. Association between Atmospheric Fine Particulate Matter and Hospital Admissions for Chronic Obstructive Pulmonary Disease in Southwestern Taiwan: A Population-Based Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:366. [PMID: 27023589 PMCID: PMC4847028 DOI: 10.3390/ijerph13040366] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 11/17/2022]
Abstract
Objectives: This paper reports on the findings of a population-based study to evaluate the relationship between atmospheric fine particulate matter (PM2.5) levels and hospital admissions for chronic obstructive pulmonary disease (COPD) in southwestern Taiwan over a three-year period, 2008–2010. Methods: Data on hospital admissions for COPD and PM2.5 levels were obtained from the National Health Insurance Research database (NHIRD) and the Environmental Protection Administration from 2008 to 2010, respectively. The lag structure of relative risks (RRs) of hospital admissions for COPD was estimated using a Poisson regression model. Results: During the study period, the overall average hospitalization rate of COPD and mean 24-h average level of PM2.5 was 0.18% and 39.37 μg/m3, respectively. There were seasonal variations in PM2.5 concentrations in southwestern Taiwan, with higher PM2.5 concentrations in both spring (average: 48.54 μg/m3) and winter (49.96 μg/m3) than in summer (25.89 μg/m3) and autumn (33.37 μg/m3). Increased COPD admissions were significantly associated with PM2.5 in both spring (February–April) and winter (October–January), with the relative risks (RRs) for every 10 μg/m3 increase in PM2.5 being 1.25 (95% CI = 1.22–1.27) and 1.24 (95% CI = 1.23–1.26), respectively, at a lag zero days (i.e., no lag days). Lag effects on COPD admissions were observed for PM2.5, with the elevated RRs beginning at lag zero days and larger RRs estimates tending to occur at longer lags (up to six days, i.e., lag 0–5 days). Conclusions: In general, findings reveal an association between atmospheric fine particulate matter (PM2.5) and hospital admissions for COPD in southwestern Taiwan, especially during both spring and winter seasons.
Collapse
Affiliation(s)
- Su-Lun Hwang
- Department of Nursing, Chang Gung University of Science and Technology, Chiayi Campus, Chiayi County 613, Taiwan.
- Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chiayi County 613, Taiwan.
| | - Su-Er Guo
- Department of Nursing, Chang Gung University of Science and Technology, Chiayi Campus, Chiayi County 613, Taiwan.
- Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chiayi County 613, Taiwan.
| | - Miao-Ching Chi
- Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chiayi County 613, Taiwan.
- Department of Respiratory Care, Chang Gung University of Science and Technology, Chiayi County 613, Taiwan.
| | - Chiang-Ting Chou
- Department of Nursing, Chang Gung University of Science and Technology, Chiayi Campus, Chiayi County 613, Taiwan.
- Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chiayi County 613, Taiwan.
| | - Yu-Ching Lin
- Department of Respiratory Care, Chang Gung University of Science and Technology, Chiayi County 613, Taiwan.
- Division of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital, Chiayi County 613, Taiwan.
- Department of Respiratory Care, Chang Gung University, Taoyuan 333, Taiwan.
| | - Chieh-Mo Lin
- Department of Nursing, Chang Gung University of Science and Technology, Chiayi Campus, Chiayi County 613, Taiwan.
- Division of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital, Chiayi County 613, Taiwan.
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.
| | - Yen-Li Chou
- Division of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital, Chiayi County 613, Taiwan.
| |
Collapse
|
13
|
Cheng YH, Lin CC, Liu JJ, Hsieh CJ. Temporal characteristics of black carbon concentrations and its potential emission sources in a southern Taiwan industrial urban area. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:3744-3755. [PMID: 24281684 DOI: 10.1007/s11356-013-2373-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 11/13/2013] [Indexed: 06/02/2023]
Abstract
This study investigates the temporal characteristics of black carbon and its potential emission sources, as well as the fractions of BC in PM2.5 levels in Kaohsiung urban area, which is an industrial city in southern Taiwan. Concentrations of BC and PM2.5 are monitored continuously from March 2006 to February 2010, using an aethalometer and a tapered element oscillating microbalance monitor. Additionally, the presence of organic compounds (or UV enhanced species) in particles at the sampling site is determined using the Delta-C (UVBC-BC) value. According to long-term measurement results, BC and PM2.5 concentrations are 3.33 and 34.0 μg m(-3), respectively, in the Kaohsiung urban area. The ratio of BC/PM2.5 is approximately 11 %. Low concentration of BC and PM2.5 in the summer of this study period is mostly likely owing to meteorological conditions that favored dispersion of local air pollutants. Nevertheless, BC concentrations peaked markedly during morning hours (7:00-11:00), likely owing to local traffic congestion. Measurement results suggest that BC is released from local traffic activities and emitted from industrial activities at this sampling site. Additionally, Delta-C values are significantly higher than zero during January-March and November-December periods in this industrial urban area, implying that UV enhanced species can be observed. At this sampling site, these UV enhanced species do not only originate from household activity and solid waste burning but also release from industrial activities. The elevated Delta-C values during nighttime (18:00-6:00) in the autumn and winter seasons are likely related to those UV enhanced species in the atmosphere, which can be condensed on particle surface under low temperature conditions. According to long-term measurement results, significantly positive Delta-C values can be observed under temperatures <20 °C and relative humidity of 60-75 % in this study. Despite the household activity and solid waste burning, the major sources of particles that are bound with UV enhanced species in this sampling site are industrial parks and a coal-fired power plant.
Collapse
Affiliation(s)
- Yu-Hsiang Cheng
- Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, 84, Gungjuan Rd, Taishan, New Taipei, 24301, Taiwan,
| | | | | | | |
Collapse
|
14
|
Lin YK, Chang SC, Lin C, Chen YC, Wang YC. Comparing ozone metrics on associations with outpatient visits for respiratory diseases in Taipei Metropolitan area. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2013; 177:177-84. [PMID: 23333210 PMCID: PMC7127381 DOI: 10.1016/j.envpol.2012.12.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Revised: 12/09/2012] [Accepted: 12/14/2012] [Indexed: 05/05/2023]
Abstract
This study reported cumulative 6-day (lag 0-5 days) relative risks (RR) and confidence intervals (CI) of daily outpatient visits for total respiratory disease (RD), asthma, and chronic airway obstruction not otherwise classified (CAO) associated with three ozone metrics (daily 1-h maximum (O3, 1 h max), 8-h average maximum (O3, 8 h max), 24-h average (O3, 24 h avg)), and an alternative oxidant indicator (Ox) in Taipei Metropolitan, using distributed lag non-linear models after controlling for potential confounders. The Ox showed the strongest association with outpatient visits for total RD (RR = 1.10, 95% CI: 1.10, 1.11) and asthma (RR = 1.18, 95% CI: 1.00, 1.39) in the cold season. The O3, 24 h avg appeared to be the optimal ozone metric associating with total RD than O3, 1 h max and O3, 8 h max based on model selection. In conclusion, outpatient visits for total RD associated with ozone vary with ozone metrics, disease and season.
Collapse
Affiliation(s)
- Yu-Kai Lin
- Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Xu-Zhou Road, Taipei 10055, Taiwan
- Harvard School of Public Health, Department of Environmental Health, Environmental and Occupational Medicine and Epidemiology Program, 677 Huntington Ave, Boston, MA 02115, USA
| | - Shuenn-Chin Chang
- Taiwan Environmental Protection Administration, 83, Sec. 1, Jhonghua Road, Taipei City 10042, Taiwan
- School of Public Health, National Defense Medical Center, 161, Sec. 6, Min-Chuan East Road, Taipei 114, Taiwan
| | - ChitSan Lin
- Department of Marine Environmental Engineering, National Kaohsiung Marine University, 142 Haijhuan Road, Nanzih District, Kaohsiung City 811, Taiwan
| | - Yi-Chun Chen
- Department of Health Management, I-Shou University, Kaohsiung 824, Taiwan
| | - Yu-Chun Wang
- Department of Bioenvironmental Engineering, College of Engineering, Chung Yuan Christian University, 200 Chung-Pei Road, Chung Li 320, Taiwan
- Corresponding author.
| |
Collapse
|
15
|
Kim SH, Yoon HJ. Climate change and respiratory allergic diseases. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2011. [DOI: 10.5124/jkma.2011.54.2.161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Sang-Heon Kim
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea
| | - Ho Joo Yoon
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea
| |
Collapse
|
16
|
Peng YP, Chen KS, Wang HK, Lai CH, Lin MH, Lee CH. Applying model simulation and photochemical indicators to evaluate ozone sensitivity in southern Taiwan. J Environ Sci (China) 2011; 23:790-797. [PMID: 21790052 DOI: 10.1016/s1001-0742(10)60479-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Ozone sensitivity was investigated using CAMx simulations and photochemical indicator ratios at three sites (Pingtung City, Chao-Chou Town, and Kenting Town) in Pingtung County in southern Taiwan during 2003 and 2004. The CAMx simulations compared fairly well with the hourly concentrations of ozone. Simulation results also showed that Pingtung City was mainly a volatile organic compounds (VOC)-sensitive regime, while Chao-Chou Town was either a VOC-sensitive or a NOx-sensitive regime, depending on the seasons. Measurements of three photochemical indicators (H2O2, HNO3, and NOy) were conducted, and simulated three transition ranges of H2O2/HNO3 (0.5-0.8), O3/HNO3 (10.3-16.2) and O3/NOy (5.7-10.8) were adopted to assess the ozone sensitive regime at the three sites. The results indicated that the three transition ranges yield consistent results with CAMx simulations at most times at Pingtung City. However, both VOC-sensitive and NOx-sensitive regimes were important at the rural site Chao-Chou Town. Kenting Town, a touring site at the southern end of Taiwan, was predominated by a NOx-sensitive regime in four seasons.
Collapse
Affiliation(s)
- Yen-Ping Peng
- Graduate Institute of Environmental Engineering, "National" Taiwan University Taipei 106, Taiwan, China.
| | | | | | | | | | | |
Collapse
|
17
|
Wang HK, Huang CH, Chen KS, Peng YP, Lai CH. Measurement and source characteristics of carbonyl compounds in the atmosphere in Kaohsiung city, Taiwan. JOURNAL OF HAZARDOUS MATERIALS 2010; 179:1115-1121. [PMID: 20427126 DOI: 10.1016/j.jhazmat.2010.03.122] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 03/29/2010] [Accepted: 03/30/2010] [Indexed: 05/29/2023]
Abstract
The concentrations of eighteen atmospheric carbonyls species were measured by the LpDNPH-Cartridge and the microcomputer air sampling device at Nan-Chie (northern part) and Hsiung-Kong (southern part) sites in Kaohsiung city, southern Taiwan. These samples were then analyzed using a high performance liquid chromatography (HPLC). Measurements showed that the highest concentrations of carbonyls were formaldehyde (18.33 and 18.74 microg m(-3)) at the Nan-Chie and Hsiung-Kong site, followed by acetaldehyde (14.90 and 15.71 microg m(-3)). The concentrations of total carbonyls were higher at Hsiung-Kong site (66.96 microg m(-3)) than at Nan-Chie site (60.41 microg m(-3)). The concentrations of total carbonyls at Nan-Chie site (or Hsiung-Kong site) were 74.06 microg m(-3) (89.99 microg m(-3)) in summer and 37.14 microg m(-3) (46.50 microg m(-3)) in winter, due to the fact that photochemical activities are stronger in summer than in winter. The results of principal component analysis (PCA)/absolute principal component scores (APCS) suggest that the primary pollution sources at Nan-Chie were vehicle exhausts (gasoline and diesel engines), stationary emissions (petrochemical and food industry) and restaurant emissions, and the primary pollution sources at Hsiung-Kong were vehicle exhausts (gasoline and diesel engines), stationary emissions (metal assembly and petrochemical industry) and restaurant emissions.
Collapse
Affiliation(s)
- H K Wang
- Institute of Environmental Engineering, National Sun Yat-Sen University, 70 Lein_hei Road, Ku-San District, Kaohsiung 80424, Taiwan, ROC
| | | | | | | | | |
Collapse
|
18
|
Shea KM, Truckner RT, Weber RW, Peden DB. Climate change and allergic disease. J Allergy Clin Immunol 2008; 122:443-53; quiz 454-5. [PMID: 18774380 DOI: 10.1016/j.jaci.2008.06.032] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 06/13/2008] [Accepted: 06/26/2008] [Indexed: 11/17/2022]
Abstract
Climate change is potentially the largest global threat to human health ever encountered. The earth is warming, the warming is accelerating, and human actions are largely responsible. If current emissions and land use trends continue unchecked, the next generations will face more injury, disease, and death related to natural disasters and heat waves, higher rates of climate-related infections, and wide-spread malnutrition, as well as more allergic and air pollution-related morbidity and mortality. This review highlights links between global climate change and anticipated increases in prevalence and severity of asthma and related allergic disease mediated through worsening ambient air pollution and altered local and regional pollen production. The pattern of change will vary regionally depending on latitude, altitude, rainfall and storms, land-use patterns, urbanization, transportation, and energy production. The magnitude of climate change and related increases in allergic disease will be affected by how aggressively greenhouse gas mitigation strategies are pursued, but at best an average warming of 1 to 2 degrees C is certain this century. Thus, anticipation of a higher allergic disease burden will affect clinical practice as well as public health planning. A number of practical primary and secondary prevention strategies are suggested at the end of the review to assist in meeting this unprecedented public health challenge.
Collapse
Affiliation(s)
- Katherine M Shea
- Department of Maternal and Child Health, School of Public Health, Chapel Hill, NC 27599-1105, USA.
| | | | | | | |
Collapse
|
19
|
Tsai DH, Wang JL, Wang CH, Chan CC. A study of ground-level ozone pollution, ozone precursors and subtropical meteorological conditions in central Taiwan. ACTA ACUST UNITED AC 2008; 10:109-18. [DOI: 10.1039/b714479b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
20
|
Villeneuve PJ, Chen L, Rowe BH, Coates F. Outdoor air pollution and emergency department visits for asthma among children and adults: a case-crossover study in northern Alberta, Canada. Environ Health 2007; 6:40. [PMID: 18157917 PMCID: PMC2254596 DOI: 10.1186/1476-069x-6-40] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2007] [Accepted: 12/24/2007] [Indexed: 05/21/2023]
Abstract
BACKGROUND Recent studies have observed positive associations between outdoor air pollution and emergency department (ED) visits for asthma. However, few have examined the possible confounding influence of aeroallergens, or reported findings among very young children. METHODS A time stratified case-crossover design was used to examine 57,912 ED asthma visits among individuals two years of age and older in the census metropolitan area of Edmonton, Canada between April 1, 1992 and March 31, 2002. Daily air pollution levels for the entire region were estimated from three fixed-site monitoring stations. Similarly, daily levels of aeroallergens were estimated using rotational impaction sampling methods for the period between 1996 and 2002. Odds ratios and their corresponding 95% confidence intervals were estimated using conditional logistic regression with adjustment for temperature, relative humidity and seasonal epidemics of viral related respiratory disease. RESULTS Positive associations for asthma visits with outdoor air pollution levels were observed between April and September, but were absent during the remainder of the year. Effects were strongest among young children. Namely, an increase in the interquartile range of the 5-day average for NO2 and CO levels between April and September was associated with a 50% and 48% increase, respectively, in the number of ED visits among children 2 - 4 years of age (p < 0.05). Strong associations were also observed with these pollutants among those 75 years of age and older. Ozone and particulate matter were also associated with asthma visits. Air pollution risk estimates were largely unchanged after adjustment for aeroallergen levels. CONCLUSION Our findings, taken together, suggest that exposure to ambient levels of air pollution is an important determinant of ED visits for asthma, particularly among young children and the elderly.
Collapse
Affiliation(s)
- Paul J Villeneuve
- Biostatistics and Epidemiology Division, Health Canada, Ottawa, Ontario, Canada
| | - Li Chen
- Biostatistics and Epidemiology Division, Health Canada, Ottawa, Ontario, Canada
| | - Brian H Rowe
- University of Alberta Hospital, 8440-112th Street, Edmonton, Alberta, Canada
| | - Frances Coates
- Aerobiology Research Laboratories, Ottawa, Ontario, Canada
| |
Collapse
|
21
|
Cheng KJ, Tsai CH, Chiang HC, Hsu CW. Meteorologically adjusted ground level ozone trends in southern Taiwan. ENVIRONMENTAL MONITORING AND ASSESSMENT 2007; 129:339-47. [PMID: 17072556 DOI: 10.1007/s10661-006-9367-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Accepted: 06/28/2006] [Indexed: 05/12/2023]
Abstract
Two methods were used to calculate the meteorologically adjusted ground level ozone trends in southern Taiwan. The first method utilized is a robust linear regression method. The second approach uses a multilayer perceptron (MLP) artificial neural network (ANN) method. The observations obtained from 16 monitoring stations were analyzed and divided into six groups by hierarchical divisive clustering procedure. The daily maximum 1 and 8 h ozone concentrations for each group are then calculated. The meteorologically adjusted trends obtained by linear regression and MLP methods are smaller than the unadjusted trends for all groups and average time. It indicts that the meteorological conditions in Taiwan tend to increase ambient ozone concentrations in recent years.
Collapse
Affiliation(s)
- Kuang-jung Cheng
- Department of Water Resources and Environmental Engineering, Tamkang University, 151 Ying-chuang Rd., Tamsui, Taipei-hsien 251, Taiwan, Republic of China
| | | | | | | |
Collapse
|