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Luben TJ, Shaffer RM, Kenyon E, Nembhard WN, Weber KA, Nuckols J, Wright JM. Comparison of Trihalomethane exposure assessment metrics in epidemiologic analyses of reproductive and developmental outcomes. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2024; 34:115-125. [PMID: 37316533 DOI: 10.1038/s41370-023-00559-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/12/2023] [Accepted: 05/31/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND Researchers have developed exposure assessment metrics for disinfection by-products (DBPs) utilizing drinking water monitoring data and accounting for spatial and temporal variability, water consumption, and showering and bathing time with an expectation of decreasing exposure misclassification compared to the use of measured concentrations at public water supply (PWS) monitoring locations alone. OBJECTIVE We used exposure data collected for a previous study of DBPs to evaluate how different sources of information impact trihalomethane (THM) exposure estimates. METHODS We compared gestational exposure estimates to THMs based on water utility monitoring data alone, statistical imputation of daily concentrations to incorporate temporal variability, and personal water consumption and use (bathing and showering). We used Spearman correlation coefficients and ranked kappa statistics to compare exposure classifications. RESULTS Exposure estimates based on measured or imputed daily THM concentrations, self-reported consumption, or bathing and showering differed substantially from estimates based solely on concentrations from PWS quarterly monitoring reports. Ranked exposure classifications, high to low quartiles or deciles, were generally consistent across each exposure metric (i.e., a subject with "high" exposure based on measured or imputed THM concentrations generally remained in the "high" category across exposure metrics.) The measured concentrations and imputed daily (i.e., spline regression) concentrations were highly correlated (r = 0.98). The weighted kappa statistics comparing exposure estimates using different exposure metrics ranged from 0.27 to 0.89, with the highest values for the ingestion + bathing/showering metrics compared to metrics for bathing/showering only (0.76 and 0.89). Bathing and showering contributed the most to "total" THM exposure estimates. IMPACT STATEMENT We compare exposure metrics capturing temporal variability and multiple estimates of personal THM exposure with THM concentrations from PWS monitoring data. Our results show exposure estimates based on imputed daily concentrations accounting for temporal variability were very similar to the measured THM concentrations. We observed low agreement between imputed daily concentrations and ingestion-based estimates. Considering additional routes of exposure (e.g., inhalation and dermal) slightly increased agreement with the measured PWS exposure estimate in this population. Overall, the comparison of exposure assessment metrics allows researchers to understand the added value of additional data collection for future epidemiologic analyses of DBPs.
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Affiliation(s)
- Thomas J Luben
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency. RTP, NC, Washington, DC, Cincinnati, OH, USA.
| | - Rachel M Shaffer
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency. RTP, NC, Washington, DC, Cincinnati, OH, USA
| | - Elaina Kenyon
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. Environmental Protection Agency, RTP, RTP, NC, USA
| | - Wendy N Nembhard
- Arkansas Center for Birth Defects Research and Prevention and the Department of Epidemiology, Fay. W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Kari A Weber
- Arkansas Center for Birth Defects Research and Prevention and the Department of Epidemiology, Fay. W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - John Nuckols
- Colorado State University, Fort Collins, CO, USA; JRN Environmental Health Sciences, LTD, North Bethesda, MD, USA
| | - J Michael Wright
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency. RTP, NC, Washington, DC, Cincinnati, OH, USA
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Tafesse N, Porcelli M, Robele Gari S, Ambelu A. Drinking Water Source, Chlorinated Water, and Colorectal Cancer: A Matched Case-Control Study in Ethiopia. ENVIRONMENTAL HEALTH INSIGHTS 2022; 16:11786302211064432. [PMID: 35023924 PMCID: PMC8743978 DOI: 10.1177/11786302211064432] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 11/12/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND There is no study conducted on the association between disinfection byproducts (DBPs) in chlorinated drinking water and colorectal cancer (CRC) in Ethiopia. Therefore, this study aimed to determine the relation between chlorine based DBPs in drinking water and CRC in Addis Ababa, Ethiopia. METHODS A facility based matched case control study was conducted involving 224 cases and 448 population controls from June 2020 to May 2021. Cases were defined as histologically confirmed CRC cases. Cases were matched with controls by residence, age, and sex using frequency and individual matching. Geocoding of cases, health facility, and georeferencing of controls were carried out. Data was collected using a pretested structured questionnaire. Pearson Chi square and Fisher's exact tests were employed to assess associations. Stratified analysis was used to detect confounding factors and effect modification. A multivariable conditional logistic regression was used to identify risk factors of CRC. RESULTS Of 214 CRC cases, 148 (69.2%) used chlorinated water whereas out of 428 controls 161 (37.6%) used chlorinated water. In the final regression model, drinking chlorinated surface water (adjusted matched odds ratio [adjusted mOR] = 2.6; 95% CI 1.7-4.0), history of swimming (adjusted mOR = 2.4; 95% CI 1.4-4.1), years at the place of current residence (adjusted mOR = 1.5; 95% CI 1.1-2.2), hot tap water use for showering (adjusted mOR; 3.8 = 95% CI 2.5-5.9) were significantly associated with CRC. The stratified analysis confirmed that smoking and meat ingestion were not effect modifiers and confounders. CONCLUSION Drinking chlorinated water for extended years is a significant risk factor for CRC in Addis Ababa, Ethiopia. In addition, hot tap water use for showering, and swimming history are risk factors for CRC. This information is essential to design integrated interventions that consider chlorination by-products and exposure routes toward the prevention and control of CRC in Ethiopia. Initiating alternative methods to chlorine disinfection of drinking water is also essential.
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Affiliation(s)
- Nebiyou Tafesse
- Ethiopian Institute of Water Resources, Addis Ababa University, Addis Ababa, Ethiopia
| | - Massimiliano Porcelli
- Department of Quality, Health, Safety & Work Environment, Kuwait Institute for Scientific Research, Kuwait City, Kuwait
| | - Sirak Robele Gari
- Ethiopian Institute of Water Resources, Addis Ababa University, Addis Ababa, Ethiopia
| | - Argaw Ambelu
- Department of Environmental Health Science and Technology, Public Health Faculty, Jimma University, Jimma, Ethiopia
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Lewis A, McKeon TP, De Roos AJ, Ravel J, Elovitz MA, Burris HH. Associations of public water system trihalomethane exposure during pregnancy with spontaneous preterm birth and the cervicovaginal microbial-immune state. ENVIRONMENTAL RESEARCH 2021; 199:111288. [PMID: 33965388 PMCID: PMC8195861 DOI: 10.1016/j.envres.2021.111288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Water total trihalomethanes (TTHMs) are disinfectant byproducts found in municipal water supplies. TTHM exposure has been linked to cancer and may be associated with adverse reproductive outcomes. A non-optimal cervicovaginal microbiota and low cervicovaginal beta-defensin-2 levels are associated with increased risk of spontaneous preterm birth. Whether TTHM exposure increases the risk of spontaneous preterm birth or alters the cervicovaginal microbial or immune state is unknown. OBJECTIVE Investigate associations of water TTHM levels with spontaneous preterm birth, a non-optimal cervicovaginal microbiota, and beta-defensin-2 levels in a completed, diverse, urban pregnancy cohort. We hypothesized that higher TTHM levels would be associated with spontaneous preterm birth, a non-optimal cervicovaginal microbiota, and lower beta-defensin-2 levels. DESIGN Methods: This was a secondary analysis of participants (n = 474) in the Motherhood & Microbiome (M&M) study (n = 2000), who lived in Philadelphia and had cervicovaginal samples analyzed for cervicovaginal microbiota composition and beta-defensin-2 levels. The microbiota was classified into community state types (CSTs). CST IV (non-optimal microbiota) is characterized by a paucity of Lactobacillus species and wide array of anaerobes. Municipal water TTHM levels were obtained from 16 sites monthly across the city of Philadelphia to establish mean residential water supply levels for each participant for the first four months of pregnancy (prior to vaginal swab collection at 16-20 weeks' gestation). Associations of water TTHM levels with spontaneous preterm birth and a non-optimal cervicovaginal microbiota birth were analyzed using multivariable logistic regression. Multivariable linear regression was used to model associations of water TTHM levels with log-transformed cervicovaginal beta-defensin-2 levels. Since water TTHM levels vary by season and beta-defensin-2 levels have been shown to differ by race, stratified models by warm (April-September) and cold (October-March) seasons as well as by self-identified race were utilized. RESULTS Participants' water supply TTHM levels (mean μg/L [SD]) were higher in the warm (53.5 [9.4]) than cold (33.4 [7.5]) season (p < 0.0001). TTHM levels were non-significantly higher among Black participants than non-Black participants (44.8 [13.5] vs. 41.8 [11.8], p = 0.07). No associations were detected between TTHM with spontaneous preterm birth (per SD increment of TTHM, aOR 0.94, 95%CI: 0.66, 1.34) or with CST IV (aOR 0.94, 95%CI: 0.86, 1.16). Counter to our hypothesis, we observed positive associations of water TTHM with log-transformed cervicovaginal beta-defensin-2 levels in unadjusted models (β 0.20 [95%CI: 0.02, 0.39]) per SD increment of TTHM), but the association was null after adjustment for season. However, in models adjusted for covariates including season and stratified by race, TTHM was significantly associated with lower beta-defensin-2 levels among non-Black participants (β -0.75 [95%CI: -1.43, -0.08]) but not among Black participants (β 0.17 [95%CI: -0.15, 0.49]), interaction p = 0.013). CONCLUSION We did not detect associations of water TTHM levels with spontaneous preterm birth or the structure of the cervicovaginal microbiota. However, the finding of a significant interaction between TTHM and race on beta-defensin-2 levels suggest that environmental exposures may contribute to differences in reproductive tract innate immune function by race. Future studies to delineate environmental contributions to the cervicovaginal microbial-immune state, a potentially important biologic underpinning for preterm birth, are warranted.
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Affiliation(s)
- Andrea Lewis
- Center of Excellence in Environmental Toxicology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas P McKeon
- Center of Excellence in Environmental Toxicology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Anneclaire J De Roos
- Department of Environmental and Occupational Health, Dornsife School of Public Health, Drexel University, Philadelphia, PA, USA
| | - Jacques Ravel
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Michal A Elovitz
- Maternal and Child Health Research Center, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Department of Obstetrics and Gynecology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Heather H Burris
- Maternal and Child Health Research Center, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Department of Pediatrics, The Children's Hospital of Philadelphia and University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA.
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Srivastava S, Purkayastha N, Chaurasia H, Muhammad T. Socioeconomic inequality in psychological distress among older adults in India: a decomposition analysis. BMC Psychiatry 2021; 21:179. [PMID: 33823847 PMCID: PMC8025542 DOI: 10.1186/s12888-021-03192-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/31/2021] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Older people coming from a lower wealth gradient are more vulnerable to have stressful life events further adding more risk for common mental health disorders and psychological distress situations. The present study explores the associations between socioeconomic and health-related variables and psychological distress among older adults in India and the contribution of such factors to the inequalities in psychological distress. METHODS A cross-sectional survey of 9181 older adults conducted as 'Building a Knowledge Base on Population Ageing in India' was assessed. Logistic regression and decomposition models were used to analyze the data. Psychological distress was measured from General Health Questionnaire (GHQ-12). The value of Cronbach's alpha was 0.90. It was having a scale of 0 to 12 on the basis of experiencing stressful symptoms and was re-coded as 0 (representing 6+ stressful symptoms) and 1 (representing 5 and fewer symptoms). RESULTS Older adults from the poored, suffering from multi-morbidity, disabled, with low activities of daily living and low instrumental activities of daily living and poor cognitive ability were suffering from high psychological distress in India. Further, factors such as religion, caste, education, living arrangements, and self-worth in the family were major contributors to the concentration of psychological distress in older adults from poor households (concentration index: - 0.23). CONCLUSION The study suggests that among older people, there is a wide disparity of experiencing psychological distress across different socio-economic groups with significant factors being responsible for inequality in psychological distress. There is a need to build a "win-win" circumstance across sectors, including a broad spectrum of health, social and economic benefits to the vulnerable older population.
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Affiliation(s)
- Shobhit Srivastava
- grid.419349.20000 0001 0613 2600International Institute for Population Sciences, Mumbai, Maharashtra 400088 India
| | - Naina Purkayastha
- grid.412023.60000 0001 0674 667XDepartment of Statistics, Dibrugarh University, Dibrugarh, Assam India
| | - Himanshu Chaurasia
- grid.416737.00000 0004 1766 871XNational Institute for Research in Reproductive Health, ICMR, Mumbai, 400088 India
| | - T. Muhammad
- grid.419349.20000 0001 0613 2600International Institute for Population Sciences, Mumbai, Maharashtra 400088 India
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Occurrence and spatial and temporal variations of disinfection by-products in the water and air of two indoor swimming pools. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2012; 9:2562-86. [PMID: 23066383 PMCID: PMC3447573 DOI: 10.3390/ijerph9082562] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 06/29/2012] [Accepted: 07/10/2012] [Indexed: 11/25/2022]
Abstract
In order to improve disinfection by-product (DBP) exposure assessment, this study was designed to document both water and air levels of these chemical contaminants in two indoor swimming pools and to analyze their within-day and day-to-day variations in both of them. Intensive sampling was carried out during two one-week campaigns to measure trihalomethanes (THMs) and chloramines (CAMs) in water and air, and haloacetic acids (HAAs) in water several times daily. Water samples were systematically collected at three locations in each pool and air samples were collected at various heights around the pool and in other rooms (e.g., changing room) in the buildings. In addition, the ability of various models to predict air concentrations from water was tested using this database. No clear trends, but actual variations of contamination levels, appeared for both water and air according to the sampling locations and times. Likewise, the available models resulted in realistic but imprecise estimates of air contamination levels from water. This study supports the recommendation that suitable minimal air and water sampling should be carried out in swimming pools to assess exposure to DBPs.
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McMaster ME. Heated indoor swimming pools, infants, and the pathogenesis of adolescent idiopathic scoliosis: a neurogenic hypothesis. Environ Health 2011; 10:86. [PMID: 21975145 PMCID: PMC3213202 DOI: 10.1186/1476-069x-10-86] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 10/05/2011] [Indexed: 05/31/2023]
Abstract
BACKGROUND In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS). In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS. PRESENTATION OF THE HYPOTHESIS Through vulnerability of the developing central nervous system to circulating toxins, and because of delayed epigenetic effects, the trunk deformity of AIS does not become evident until adolescence. In mature healthy swimmers using such pools, the circulating neurotoxins detected are chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Cyanogen chloride and dichloroacetonitrile have also been detected. TESTING THE HYPOTHESIS In infants, the putative portals of entry to the blood could be dermal, oral, or respiratory; and entry of such circulating small molecules to the brain are via the blood-brain barrier, blood-cerebrospinal fluid barrier, and circumventricular organs. Barrier mechanisms of the developing brain differ from those of adult brain and have been linked to brain development. During the first 6 months of life cerebrospinal fluid contains higher concentrations of specific proteins relative to plasma, attributed to mechanisms continued from fetal brain development rather than immaturity. IMPLICATIONS OF THE HYPOTHESIS The hypothesis can be tested. If confirmed, there is potential to prevent some children from developing AIS.
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Affiliation(s)
- Marianne E McMaster
- Scottish National Paediatric Spine Deformity Centre, Royal Hospital for Sick Children, Edinburgh, UK.
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Viana RB, Cavalcante RM, Braga FMG, Viana AB, de Araujo JC, Nascimento RF, Pimentel AS. Risk assessment of trihalomethanes from tap water in Fortaleza, Brazil. ENVIRONMENTAL MONITORING AND ASSESSMENT 2009; 151:317-25. [PMID: 18365760 DOI: 10.1007/s10661-008-0273-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Accepted: 03/03/2008] [Indexed: 05/12/2023]
Abstract
The cancer risks (CR) by oral ingestion, dermal absorption, and inhalation exposure of trihalomethanes (THM) from tap water of ten districts in Fortaleza, Brazil were estimated. The mean levels of THM compounds were obtained in Fortaleza tap water as follow: 63.9 microg L(-1) for chloroform (CHCl(3)), 40.0 microg L(-1) for bromodichloromethane (CHBrCl(2)), and 15.6 microg L(-1) for dibromochloromethane (CHBr(2)Cl). Bromoform (CHBr(3)) was not detected. The mean CR for THMs in tap water is 3.96 x 10(-4). The results indicate that Fortaleza residents have a higher CR by inhalation than dermal absorption and oral ingestion. The CR for CHCl(3) contributes with 68% as compared with the total CR, followed by CHBrCl(2) (21%), and CHBr(2)Cl (11%). The hazard index (HI) is about ten times lower than unity, not indicating non-cancer effects.
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Affiliation(s)
- Rommel B Viana
- Departamento de Química e Física Molecular, Instituto de Química de São Carlos, Universidade de São Paulo, Av. Trabalhador São Carlense, 400 Cx. Postal 780, 13560-970, São Carlos, SP, Brazil.
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Varraso R, Massin N, Hery M, Fradier-Dusch M, Michaely JP, Fournier M, Hubert G, Biette P, Rieger B, Berthelin A, Hecht G, Nadif R. Not only training but also exposure to chlorinated compounds generates a response to oxidative stimuli in swimmers. Toxicol Ind Health 2004; 18:269-78. [PMID: 14992464 PMCID: PMC2973981 DOI: 10.1191/0748233702th150oa] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Relations between exposure to chlorinated compounds and biological markers of response to oxidative stimuli were investigated in swimmers, taking into account the effect of training. Twenty-two male swimmers aged 15-25 years were surveyed twice. Prevalence of irritant symptoms and asthma and number of hours of training were reported. Exposure to nitrogen trichloride (NCl3) and blood response to oxidative stimuli [catalase, superoxide dismutase (Cu2+/Zn2+ SOD), glutathione peroxidase (GSH-Px) activities and ceruloplasmin, ferritin and total antioxidant concentrations] were measured. Univariate analyses were completed by multivariate analyses. High prevalences of irritant symptoms and asthma were found. Multivariate analysis confirmed the results of the univariate analyses and showed that Cu2+/Zn2+ SOD activity was increased by exposure and by training (P = 0.01, P = 0.0001, respectively). Erythrocyte GSH-Px was decreased, whereas plasma GSH-Px was increased by exposure (P = 0.002, P = 0.002). No other association was found. Higher irritant symptoms and increases in the activities of erythrocyte Cu2+/Zn2+ SOD and of plasma GSH-Px with exposure support the hypothesis that the production of reactive oxygen species is not only related to training but also to exposure to chlorinated compounds. Other athletes tend to have respiratory problems such as asthma, but the exposure to chlorinated compounds may increase the respiratory disease among swimmers.
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Affiliation(s)
- Raphaëlle Varraso
- INSERM U420, Faculté de Médecine, BP 184, 54505 Vandauvre-leś-Nancy, France.
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Whitaker HJ, Nieuwenhuijsen MJ, Best NG. The relationship between water concentrations and individual uptake of chloroform: a simulation study. ENVIRONMENTAL HEALTH PERSPECTIVES 2003; 111:688-94. [PMID: 12727595 PMCID: PMC1241476 DOI: 10.1289/ehp.5963] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We simulated the relationship between water chloroform concentrations and chloroform uptake in pregnant women to assess the potential extent of exposure measurement error in epidemiologic studies of the health effects of exposure to water disinfection by-products. Data from the literature were used to assign statistical distributions to swimming pool chloroform concentrations, frequency and duration of swimming, showering and bathing, and average tap water consumption. Measured increases in blood chloroform concentrations after these activities were used to estimate average uptake per microgram per liter chloroform in the water, per minute spent in the activity or per liter consumed. Given average tap water chloroform concentrations from a U.K. epidemiologic study, an average daily uptake over 90 days was simulated for 300,000 mothers. The correlation between simulated uptakes and home tap chloroform concentration was 0.6. Mothers who swam regularly received far greater doses than did nonswimmers. Results suggest there will be considerable attenuation in risk estimates and/or power loss in epidemiologic studies if the putative agent is chloroform.
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Affiliation(s)
- Heather J Whitaker
- Small Area Health Statistics Unit, Faculty of Medicine, Department of Epidemiology and Public Health, Imperial College, London, United Kingdom.
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Chu H, Nieuwenhuijsen MJ. Distribution and determinants of trihalomethane concentrations in indoor swimming pools. Occup Environ Med 2002; 59:243-7. [PMID: 11934951 PMCID: PMC1740275 DOI: 10.1136/oem.59.4.243] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES For many decades chlorination has been used as a major disinfectant process for public drinking and swimming pool water in many countries. However, there has been rising concern over the possible link between disinfectant byproducts (DBPs) and adverse reproductive outcomes. The purpose of this study was to estimate the concentrations of trihalomethanes (THMs) in some indoor swimming pools in London and their variation within and between pools and any correlation with other factors. METHODS Water samples were collected from eight different indoor swimming pools in London. A total of 44 pool samples were collected and analysed for total organic content (TOC) and THMs. Water and air temperature were measured along with the pH during the collection of pool samples. The level of turbulence and the number of people in the pool at the time were also assessed. RESULTS The geometric mean concentration for all swimming pools of TOC was 5.8 mg/l, of total THMs (TTHMs) 132.4 microg/l, and for chloroform 113.3 microg/l. There was a clear positive linear correlation between the number of people in the swimming pool and concentrations of TTHMs and chloroform (r=0.7, p<0.01), and a good correlation between concentrations of TOC and TTHMs (r=0.5, p<0.05) and water temperature and concentrations of TTHMs (r=0.5, p<0.01). There was a larger variation in THMs within pools than between pools. CONCLUSION Relatively high concentrations of THMs were found in London's indoor swimming pools. The levels correlated with the number of people in the pool, water temperature, and TOC. The variation in concentrations of THMs was greater within pools than between pools.
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Affiliation(s)
- H Chu
- Imperial College of Science, Technology and Medicine, Department of Environmental Science and Technology, Royal School of Mines, Prince Consort Road, London SW7 2BP, UK
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Arbuckle TE, Hrudey SE, Krasner SW, Nuckols JR, Richardson SD, Singer P, Mendola P, Dodds L, Weisel C, Ashley DL, Froese KL, Pegram RA, Schultz IR, Reif J, Bachand AM, Benoit FM, Lynberg M, Poole C, Waller K. Assessing exposure in epidemiologic studies to disinfection by-products in drinking water: report from an international workshop. ENVIRONMENTAL HEALTH PERSPECTIVES 2002; 110 Suppl 1:53-60. [PMID: 11834463 PMCID: PMC1241147 DOI: 10.1289/ehp.02110s153] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The inability to accurately assess exposure has been one of the major shortcomings of epidemiologic studies of disinfection by-products (DBPs) in drinking water. A number of contributing factors include a) limited information on the identity, occurrence, toxicity, and pharmacokinetics of the many DBPs that can be formed from chlorine, chloramine, ozone, and chlorine dioxide disinfection; b) the complex chemical interrelationships between DBPs and other parameters within a municipal water distribution system; and c) difficulties obtaining accurate and reliable information on personal activity and water consumption patterns. In May 2000, an international workshop was held to bring together various disciplines to develop better approaches for measuring DBP exposure for epidemiologic studies. The workshop reached consensus about the clear need to involve relevant disciplines (e.g., chemists, engineers, toxicologists, biostatisticians and epidemiologists) as partners in developing epidemiologic studies of DBPs in drinking water. The workshop concluded that greater collaboration of epidemiologists with water utilities and regulators should be encouraged in order to make regulatory monitoring data more useful for epidemiologic studies. Similarly, exposure classification categories in epidemiologic studies should be chosen to make results useful for regulatory or policy decision making.
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Affiliation(s)
- Tye E Arbuckle
- Bureau of Reproductive and Child Health, Health Canada, Ottawa, Ontario, Canada.
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Nieuwenhuijsen MJ, Toledano MB, Eaton NE, Fawell J, Elliott P. Chlorination disinfection byproducts in water and their association with adverse reproductive outcomes: a review. Occup Environ Med 2000; 57:73-85. [PMID: 10711274 PMCID: PMC1739910 DOI: 10.1136/oem.57.2.73] [Citation(s) in RCA: 312] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES AND METHODS Chlorination has been the major disinfectant process for domestic drinking water for many years. Concern about the potential health effects of the byproducts of chlorination has prompted the investigation of the possible association between exposure to these byproducts and incidence of human cancer, and more recently, with adverse reproductive outcomes. This paper evaluates both the toxicological and epidemiological data involving chlorination disinfection byproducts (DBPs) and adverse reproductive outcomes, and makes recommendations for future research. RESULTS AND CONCLUSIONS Relatively few toxicological and epidemiological studies have been carried out examining the effects of DBPs on reproductive health outcomes. The main outcomes of interest so far have been low birth weight, preterm delivery, spontaneous abortions, stillbirth, and birth defects--in particular central nervous system, major cardiac defects, oral cleft, and respiratory, and neural tube defects. Various toxicological and epidemiological studies point towards an association between trihalomethanes (THMs), one of the main DBPs and marker for total DBP load, and (low) birth weight, although the evidence is not conclusive. Administered doses in toxicological studies have been high and even though epidemiological studies have mostly shown excess risks, these were often not significant and the assessment of exposure was often limited. Some studies have shown associations for DBPs and other outcomes such as spontaneous abortions, stillbirth and birth defects, and although the evidence for these associations is weaker it is gaining weight. There is no evidence for an association between THMs and preterm delivery. The main limitation of most studies so far has been the relatively crude methodology, in particular for assessment of exposure. RECOMMENDATIONS Large, well designed epidemiological studies focusing on well defined end points taking into account relevant confounders and with particular emphasis on exposure characterisation are ideally needed to confirm or refute these preliminary findings. In practice, these studies may be impracticable, partly due to the cost involved, but this is an issue that can be put right--for example, by use of subsets of the population in the design of exposure models. The studies should also reflect differences of culture and water treatment in different parts of the world. To identify the specific components that may be of aetiological concern and hence to fit the most appropriate exposure model with which to investigate human exposure to chlorinated DBPs, further detailed toxicological assessments of the mixture of byproducts commonly found in drinking water are also needed.
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Affiliation(s)
- M J Nieuwenhuijsen
- Department of Epidemiology and Public Health, Imperial College School of Medicine at St Mary's, London, UK
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Gordon SM, Wallace LA, Callahan PJ, Kenny DV, Brinkman MC. Effect of water temperature on dermal exposure to chloroform. ENVIRONMENTAL HEALTH PERSPECTIVES 1998; 106:337-45. [PMID: 9618350 PMCID: PMC1532999 DOI: 10.1289/ehp.98106337] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We have developed and applied a new measurement methodology to investigate dermal absorption of chloroform while bathing. Ten subjects bathed in chlorinated water while breathing pure air through a face mask. Their exhaled breath was delivered to a glow discharge source/ion trap mass spectrometer for continuous real-time measurement of chloroform in the breath. This new method provides abundant data compared to previous discrete time-integrated breath sampling methods. The method is particularly well suited to studying dermal exposure because the full face mask eliminates exposure to contaminated air. Seven of the 10 subjects bathed in water at two or three different temperatures between 30 degrees C and 40 degrees C. Subjects at the highest temperatures exhaled about 30 times more chloroform than the same subjects at the lowest temperatures. This probably results from a decline in blood flow to the skin at the lower temperatures as the body seeks to conserve heat forcing the chloroform to diffuse over a much greater path length before encountering the blood. These results suggest that pharmacokinetic models need to employ temperature-dependent parameters. Two existing models predict quite different times of about 12 min and 29 min for chloroform flux through the stratum corneum to reach equilibrium. At 40 degrees C, the time for the flux to reach a near steady-state value is 6-9 min. Although uptake and decay processes involve several body compartments, the complicating effect of the stratum corneum lag time made it difficult to fit multiexponential curves to the data; however, a single-compartment model gave a satisfactory fit.
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Affiliation(s)
- S M Gordon
- Battelle Memorial Institute, Columbus, OH 43201, USA
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Doyle TJ, Zheng W, Cerhan JR, Hong CP, Sellers TA, Kushi LH, Folsom AR. The association of drinking water source and chlorination by-products with cancer incidence among postmenopausal women in Iowa: a prospective cohort study. Am J Public Health 1997; 87:1168-76. [PMID: 9240108 PMCID: PMC1380892 DOI: 10.2105/ajph.87.7.1168] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES This study assessed the association of drinking water source and chlorination by-product exposure with cancer incidence. METHODS A cohort of 28,237 Iowa women reported their drinking water source. Exposure to chlorination by-products was determined from statewide water quality data. RESULTS In comparison with women who used municipal ground-water sources, women with municipal surface water sources were at an increased risk of colon cancer and all cancers combined. A clear dose-response relation was observed between four categories of increasing chloroform levels in finished drinking water and the risk of colon cancer and all cancers combined. The relative risks were 1.00, 1.06, 1.39, and 1.68 for colon cancer and 1.00, 1.04, 1.24, and 1.25 for total cancers. No consistent association with either water source or chloroform concentration was observed for other cancer sites. CONCLUSIONS These results suggest that exposure to chlorination by-products in drinking water is associated with increased risk of colon cancer.
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Affiliation(s)
- T J Doyle
- Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis 55454-1015, USA
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Lindstrom AB, Pleil JD, Berkoff DC. Alveolar breath sampling and analysis to assess trihalomethane exposures during competitive swimming training. ENVIRONMENTAL HEALTH PERSPECTIVES 1997; 105:636-42. [PMID: 9288498 PMCID: PMC1470079 DOI: 10.1289/ehp.97105636] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Alveolar breath sampling was used to assess trihalomethane (THM) exposures encountered by collegiate swimmers during a typical 2-hr training period in an indoor natatorium. The breath samples were collected at regular intervals before, during, and for 3 hr after a moderately intense training workout. Integrated and grab whole-air samples were collected during the training period to help determine inhalation exposures, and pool water samples were collected to help assess dermal exposures. Resulting breath samples collected during the workout demonstrated a rapid uptake of two THMs (chloroform and bromodichloromethane), with chloroform concentrations exceeding the natatorium air levels within 8 min after the exposure began. Chloroform levels continued to rise steeply until they were more than two times the indoor levels, providing evidence that the dermal route of exposure was relatively rapid and ultimately more important than the inhalation route in this training scenario. Chloroform elimination after the exposure period was fitted to a three compartment model that allowed estimation of compartmental half-lives, resulting minimum bloodborne dose, and an approximation of the duration of elevated body burdens. We estimated the dermal exposure route to account for 80% of the blood chloroform concentration and the transdermal diffusion efficiency from the water to the blood to in excess of 2%. Bromodichloromethane elimination was fitted to a two compartment model which provided evidence of a small, but measurable, body burden of this THM resulting from vigorous swim training. These results suggest that trihalomethane exposures for competitive swimmers under prolonged, high-effort training are common and possibly higher than was previously thought and that the dermal exposure route is dominant. The exposures and potential risks associated with this common recreational activity should be more thoroughly investigated.
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Affiliation(s)
- A B Lindstrom
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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Wallace L, Buckley T, Pellizzari E, Gordon S. Breath measurements as volatile organic compound biomarkers. ENVIRONMENTAL HEALTH PERSPECTIVES 1996; 104 Suppl 5:861-9. [PMID: 8933027 PMCID: PMC1469714 DOI: 10.1289/ehp.96104s5861] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A brief review of the uses of breath analysis in studies of environmental exposure to volatile organic compounds (VOCs) is provided. The U.S. Environmental Protection Agency's large-scale Total Exposure Assessment Methodology Studies have measured concentrations of 32 target VOCs in the exhaled breath of about 800 residents of various U.S. cities. Since the previous 12-hr integrated personal air exposures to the same chemicals were also measured, the relation between exposure and body burden is illuminated. Another major use of the breath measurements has been to detect unmeasured pathways of exposure; the major impact of active smoking on exposure to benzene and styrene was detected in this way. Following the earlier field studies, a series of chamber studies have provided estimates of several important physiological parameters. Among these are the fraction, f, of the inhaled chemical that is exhaled under steady-state conditions and the residence times. tau i in several body compartments, which may be associated with the blood (or liver), organs, muscle, and fat. Most of the targeted VOCs appear to have similar residence times of a few minutes, 30 min, several hours, and several days in the respective tissue groups. Knowledge of these parameters can be helpful in estimating body burden from exposure or vice versa and in planning environmental studies, particularly in setting times to monitor breath in studies of the variation with time of body burden. Improvements in breath methods have made it possible to study short-term peak exposure situations such as filling a gas tank or taking a shower in contaminated water.
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Affiliation(s)
- L Wallace
- Atmospheric Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Reston, Virginia 22091, USA.
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