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Azuma K, Jinno H, Tanaka-Kagawa T, Sakai S. Risk assessment concepts and approaches for indoor air chemicals in Japan. Int J Hyg Environ Health 2020; 225:113470. [DOI: 10.1016/j.ijheh.2020.113470] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 12/08/2019] [Accepted: 01/27/2020] [Indexed: 12/13/2022]
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Godri Pollitt KJ, Kim JH, Peccia J, Elimelech M, Zhang Y, Charkoftaki G, Hodges B, Zucker I, Huang H, Deziel NC, Murphy K, Ishii M, Johnson CH, Boissevain A, O'Keefe E, Anastas PT, Orlicky D, Thompson DC, Vasiliou V. 1,4-Dioxane as an emerging water contaminant: State of the science and evaluation of research needs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 690:853-866. [PMID: 31302550 DOI: 10.1016/j.scitotenv.2019.06.443] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/26/2019] [Accepted: 06/26/2019] [Indexed: 06/10/2023]
Abstract
1,4-Dioxane has historically been used to stabilize chlorinated solvents and more recently has been found as a contaminant of numerous consumer and food products. Once discharged into the environment, its physical and chemical characteristics facilitate migration in groundwater, resulting in widespread contamination of drinking water supplies. Over one-fifth of U.S. public drinking water supplies contain detectable levels of 1,4-dioxane. Remediation efforts using common adsorption and membrane filtration techniques have been ineffective, highlighting the need for alternative removal approaches. While the data evaluating human exposure and health effects are limited, animal studies have shown chronic exposure to cause carcinogenic responses in the liver across multiple species and routes of exposure. Based on this experimental evidence, the U.S. Environmental Protection Agency has listed 1,4-dioxane as a high priority chemical and classified it as a probable human carcinogen. Despite these health concerns, there are no federal or state maximum contaminant levels for 1,4-dioxane. Effective public health policy for this emerging contaminant requires additional information about human health effects, chemical interactions, environmental fate, analytical detection, and treatment technologies. This review highlights the current state of knowledge, key uncertainties, and data needs for future research on 1,4-dioxane.
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Affiliation(s)
- Krystal J Godri Pollitt
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT 06510, United States.
| | - Jae-Hong Kim
- Department of Chemical & Environmental Engineering, School of Engineering & Applied Science, Yale University, New Haven, CT 06520, United States
| | - Jordan Peccia
- Department of Chemical & Environmental Engineering, School of Engineering & Applied Science, Yale University, New Haven, CT 06520, United States
| | - Menachem Elimelech
- Department of Chemical & Environmental Engineering, School of Engineering & Applied Science, Yale University, New Haven, CT 06520, United States
| | - Yawei Zhang
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT 06510, United States; Department of Surgery, School of Medicine, Yale University, New Haven, CT 06520, United States
| | - Georgia Charkoftaki
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT 06510, United States
| | - Brenna Hodges
- Department of Chemical & Environmental Engineering, School of Engineering & Applied Science, Yale University, New Haven, CT 06520, United States
| | - Ines Zucker
- Department of Chemical & Environmental Engineering, School of Engineering & Applied Science, Yale University, New Haven, CT 06520, United States
| | - Huang Huang
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT 06510, United States
| | - Nicole C Deziel
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT 06510, United States
| | - Kara Murphy
- Northeast States for Coordinated Air Use Management (NESCAUM), Boston, MA 02111, United States
| | - Momoko Ishii
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT 06510, United States
| | - Caroline H Johnson
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT 06510, United States
| | | | - Elaine O'Keefe
- Office of Public Health Practice, School of Public Health, Yale University, New Haven, CT 06510, United States
| | - Paul T Anastas
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT 06510, United States; Center for Green Chemistry and Green Engineering, Department of Chemistry, Yale School of Forestry & Environmental Studies, New Haven, CT 06511, United States
| | - David Orlicky
- Department of Pathology, University of Colorado School of Medicine, Aurora, CO 80045, United States
| | - David C Thompson
- Department of Clinical Pharmacy, University of Colorado School of Pharmacy, Aurora, CO 80045, United States
| | - Vasilis Vasiliou
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT 06510, United States.
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Tohon H, Valcke M, Haddad S. An assessment of the impact of multi‐route co‐exposures on human variability in toxicokinetics: A case study with binary and quaternary mixtures of volatile drinking water contaminants. J Appl Toxicol 2019; 39:974-991. [DOI: 10.1002/jat.3787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/14/2018] [Accepted: 01/19/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Honesty Tohon
- Department of Environmental and Occupational Health, ESPUM, IRSPUMUniversité de Montréal Montreal QC Canada
| | - Mathieu Valcke
- Department of Environmental and Occupational Health, ESPUM, IRSPUMUniversité de Montréal Montreal QC Canada
- Institut national de santé publique du Québec Montréal QC Canada
| | - Sami Haddad
- Department of Environmental and Occupational Health, ESPUM, IRSPUMUniversité de Montréal Montreal QC Canada
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Akiyama M, Matsui Y, Kido J, Matsushita T, Shirasaki N. Monte-Carlo and multi-exposure assessment for the derivation of criteria for disinfection byproducts and volatile organic compounds in drinking water: Allocation factors and liter-equivalents per day. Regul Toxicol Pharmacol 2018; 95:161-174. [PMID: 29555557 DOI: 10.1016/j.yrtph.2018.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 03/11/2018] [Accepted: 03/13/2018] [Indexed: 11/27/2022]
Abstract
The probability distributions of total potential doses of disinfection byproducts and volatile organic compounds via ingestion, inhalation, and dermal exposure were estimated with Monte Carlo simulations, after conducting physiologically based pharmacokinetic model simulations to takes into account the differences in availability between the three exposures. If the criterion that the 95th percentile estimate equals the TDI (tolerable daily intake) is regarded as protecting the majority of a population, the drinking water criteria would be 140 (trichloromethane), 66 (bromodichloromethane), 157 (dibromochloromethane), 203 (tribromomethane), 140 (dichloroacetic acid), 78 (trichloroacetic acid), 6.55 (trichloroethylene, TCE), and 22 μg/L (perchloroethylene). The TCE criterion was lower than the Japanese Drinking Water Quality Standard (10 μg/L). The latter would allow the intake of 20% of the population to exceed the TDI. Indirect inhalation via evaporation from water, especially in bathrooms, was the major route of exposure to compounds other than haloacetic acids (HAAs) and accounted for 1.2-9 liter-equivalents/day for the median-exposure subpopulation. The ingestion of food was a major indirect route of exposure to HAAs. Contributions of direct water intake were not very different for trihalomethanes (30-45% of TDIs) and HAAs (45-52% of TDIs).
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Affiliation(s)
- Megumi Akiyama
- Graduate School of Engineering, Hokkaido University, N13W8, Sapporo 060-8628, Japan
| | - Yoshihiko Matsui
- Faculty of Engineering, Hokkaido University, N13W8, Sapporo 060-8628, Japan.
| | - Junki Kido
- Graduate School of Engineering, Hokkaido University, N13W8, Sapporo 060-8628, Japan
| | - Taku Matsushita
- Faculty of Engineering, Hokkaido University, N13W8, Sapporo 060-8628, Japan.
| | - Nobutaka Shirasaki
- Faculty of Engineering, Hokkaido University, N13W8, Sapporo 060-8628, Japan.
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Wongsasuluk P, Chotpantarat S, Siriwong W, Robson M. Using urine as a biomarker in human exposure risk associated with arsenic and other heavy metals contaminating drinking groundwater in intensively agricultural areas of Thailand. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2018; 40:323-348. [PMID: 28176197 DOI: 10.1007/s10653-017-9910-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 01/18/2017] [Indexed: 06/06/2023]
Abstract
Urine used as a biomarker was collected and compared between two groups of participants: (1) a groundwater-drinking group and (2) a non-groundwater-drinking group in intensively agricultural areas in Ubon Ratchathani province, Thailand. The statistical relationship with the metal concentration in shallow groundwater wells was established with urine data. According to the groundwater data, the health risk assessment results for four metals appeared to be higher for participants who drank groundwater than for the other group. The carcinogenic risk and non-carcinogenic risk of arsenic (As) were found in 25.86 and 31.03% of participants, respectively. For lead (Pb), 13.79% of the participants had a non-carcinogenic risk. Moreover, 30 of the 58 participants in the groundwater-drinking group had As urine higher than the standard, and 26, 2 and 9 of the 58 participants had above-standard levels for cadmium (Cd), Pb and mercury (Hg) in urine, respectively. Both the risk assessment and biomarker level of groundwater-drinking participants were higher than in the other group. The results showed an average drinking rate of approximately 4.21 ± 2.73 L/day, which is twice as high as the standard. Interestingly, the As levels in the groundwater correlated with those in the urine of the groundwater-drinking participants, but not in the non-groundwater-drinking participants, as well as with the As-related cancer and non-carcinogenic risks. The hazard index (HI) of the 100 participants ranged from 0.00 to 25.86, with an average of 1.51 ± 3.63 higher than the acceptable level, revealing that 28 people appeared to have non-carcinogenic risk levels (24 and 4 people for groundwater-drinking participants and non-groundwater-drinking participants, respectively). Finally, the associated factors of heavy metals in urine were the drinking water source, body weight, smoking, sex and use of personal protective equipment.
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Affiliation(s)
- Pokkate Wongsasuluk
- International Postgraduate Programs in Environmental Management, Graduate School, Chulalongkorn University, Bangkok, 10330, Thailand
- Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok, 10330, Thailand
| | - Srilert Chotpantarat
- Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok, 10330, Thailand.
- Department of Geology, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
- Research Program on Toxic Substance Management in the Mining Industry, Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok, Thailand.
- Research Unit on Site Remediation on Metals Management from Industry and Mining (Site Rem), Chulalongkorn University, Bangkok, Thailand.
| | - Wattasit Siriwong
- Thai Fogarty ITREOH Center, Chulalongkorn University, Bangkok, 10330, Thailand
- College of Public Health Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Mark Robson
- Thai Fogarty ITREOH Center, Chulalongkorn University, Bangkok, 10330, Thailand
- New Jersey Agricultural Experiment Station, Rutgers University, New Brunswick, NJ, USA
- School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ, USA
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Krishnan K, Carrier R. A decision tree approach to screen drinking water contaminants for multiroute exposure potential in developing guideline values. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2017; 35:173-187. [PMID: 28581903 DOI: 10.1080/10590501.2017.1328844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The consideration of inhalation and dermal routes of exposures in developing guideline values for drinking water contaminants is important. However, there is no guidance for determining the eligibility of a drinking water contaminant for its multiroute exposure potential. The objective of the present study was to develop a 4-step framework to screen chemicals for their dermal and inhalation exposure potential in the process of developing guideline values. The proposed framework emphasizes the importance of considering basic physicochemical properties prior to detailed assessment of dermal and inhalation routes of exposure to drinking water contaminants in setting guideline values.
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Affiliation(s)
| | - Richard Carrier
- b Water and Air Quality Bureau, Health Canada , Ottawa , Ontario , Canada
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Kenyon EM, Eklund C, Leavens T, Pegram RA. Development and application of a human PBPK model for bromodichloromethane to investigate the impacts of multi-route exposure. J Appl Toxicol 2015; 36:1095-111. [PMID: 26649444 DOI: 10.1002/jat.3269] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 10/05/2015] [Accepted: 10/26/2015] [Indexed: 12/25/2022]
Abstract
As a result of its presence in water as a volatile disinfection byproduct, bromodichloromethane (BDCM), which is mutagenic, poses a potential health risk from exposure via oral, dermal and inhalation routes. We developed a refined human physiologically based pharmacokinetic (PBPK) model for BDCM (including new chemical-specific human parameters) to evaluate the impact of BDCM exposure during showering and bathing on important measures of internal dose compared with oral exposure. The refined model adequately predicted data from the published literature for oral, dermal and bathing/showering exposures. A liter equivalency approach (L-eq) was used to estimate BDCM concentration in a liter of water consumed by the oral route that would be required to produce the same internal dose of BDCM resulting from a 20-min bath or a 10-min shower in water containing 10 µg l(-1) BDCM. The oral liter equivalent concentrations for the bathing scenario were 605, 803 and 5 µg l(-1) BDCM for maximum venous blood concentration (Cmax), the area under the curve (AUCv) and the amount metabolized in the liver per hour (MBDCM), respectively. For a 10-min showering exposure, the oral L-eq concentrations were 282, 312 and 2.1 µg l(-1) for Cmax, AUC and MBDCM, respectively. These results demonstrate large contributions of dermal and inhalation exposure routes to the internal dose of parent chemical reaching the systemic circulation, which could be transformed to mutagenic metabolites in extrahepatic target tissues. Thus, consideration of the contribution of multiple routes of exposure when evaluating risks from water-borne BDCM is needed, and this refined human model will facilitate improved assessment of internal doses from real-world exposures. Published 2015. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
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Affiliation(s)
- Elaina M Kenyon
- Integrated Systems Toxicology Division, U.S. EPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC, USA
| | - Christopher Eklund
- Integrated Systems Toxicology Division, U.S. EPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC, USA
| | | | - Rex A Pegram
- Integrated Systems Toxicology Division, U.S. EPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC, USA
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Ileka-Priouzeau S, Campagna C, Legay C, Deonandan R, Rodriguez MJ, Levallois P. Women exposure during pregnancy to haloacetaldehydes and haloacetonitriles in drinking water and risk of small-for-gestational-age neonate. ENVIRONMENTAL RESEARCH 2015; 137:338-348. [PMID: 25601737 DOI: 10.1016/j.envres.2015.01.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 01/05/2015] [Accepted: 01/08/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND Past studies have examined the effects of maternal exposure to water chlorination disinfection by-products (DBPs), such as trihalomethanes (THMs) and haloacetic acids (HAAs) during pregnancy. However, no human-based study has yet evaluated the effect of emerging DBPs, such as haloacetaldehydes (HAs) and haloacetonitriles (HANs) on small-for-gestational-age (SGA) status in newborns. OBJECTIVE This study aims to assess the association between maternal multiroute exposure to HAs and HANs during the third trimester of pregnancy and SGA status at birth, among neonates delivered by women residing in the Quebec City area (Province of Quebec, Canada). We also evaluated the interaction between exposure to these emerging unregulated by-products and regulated DBPs also found in drinking water (THMs and HAAs), for which a positive association with adverse reproductive outcomes has been suggested in previous studies. METHODS We conducted a population-based case-control study in the Quebec City area. SGA newborns (n=330) were compared to 1100 controls, with matching based on calendar week of birth. HA and HAN concentrations in drinking water at participant's tap were estimated using spatio-temporal strategy based on bimonthly measurements carried out at several locations in the participant's distribution system. A computer-assisted telephone interview was completed to collect information on individual habits of water consumption and water related activities in order to determine individual multiroute exposure. This enabled us to estimate the dose of HAs and HANs absorbed daily by each participant. Associations between total HA, HAN concentrations in drinking water and SGA were analyzed. Associations between the daily-absorbed doses of these emerging DBPs and SGA were also analyzed. Odds ratios (ORs) comparing the 4th quartile of exposure to the reference group (the first three quartiles) were obtained by means of conditional logistic regression, and controlling for potential confounders. RESULTS Globally, no evidence of increased risk of SGA was found with total HA and HAN concentrations in tap water when participants in the 4th quartile of exposure were compared to the first three quartiles (OR=1.0; 95% CI [0.7-1.5] and OR=0.8; 95% CI [0.6-1.2], respectively). Similarly, no association was found with the daily-absorbed doses of total HAs or HANs (OR=0.9; 95% CI [0.6-1.3] and OR=1.1; 95% CI [0.7-1.6], respectively). However, a small non statistically significant association was found between the dose of brominated HA and SGA (OR=1.4; 95% CI [0.9-2.1]). Also, in spite of the lack of interaction between other DBP classes, an unexpected negative interaction was observed between concentration of chloral hydrate (CH) (which represents the main HA species), and regulated DBPs (P=0.006). CONCLUSION In this population, exposure to low levels of HAs and HANs during the third trimester of pregnancy through drinking water was not associated to SGA status in newborns. Nonetheless, more research is needed to clarify possible effect of brominated compounds and interaction between different DBPs.
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Affiliation(s)
- Samuel Ileka-Priouzeau
- Département de médecine sociale et préventive, Faculté de médecine, Université Laval, 1050 Avenue de la Médecine, Québec Québec, Canada G1V 0A6; Axe santé des populations et pratiques optimales en santé, Centre de recherche du CHU de Québec, 2705 Boulevard Laurier, Québec Québec, Canada G1V 2L9
| | - Céline Campagna
- Direction de la santé environnementale et de la toxicologie, Institut national de santé publique du Québec, 945 Avenue Wolfe, Québec Québec, Canada G1V 5B3
| | - Christelle Legay
- Chaire de recherche en eau potable, École supérieure d'aménagement du territoire et de développement régional, Université Laval, Pavillon Félix-Antoine-Savard, 2325 rue des Bibliothèques, Québec Québec, Canada G1V 0A6
| | - Raywat Deonandan
- Interdisciplinary School of Public Health, University of Ottawa, Thompson Hall, 25 University Private, Ottawa Ontario, Canada K1N 6X1
| | - Manuel J Rodriguez
- Chaire de recherche en eau potable, École supérieure d'aménagement du territoire et de développement régional, Université Laval, Pavillon Félix-Antoine-Savard, 2325 rue des Bibliothèques, Québec Québec, Canada G1V 0A6
| | - Patrick Levallois
- Département de médecine sociale et préventive, Faculté de médecine, Université Laval, 1050 Avenue de la Médecine, Québec Québec, Canada G1V 0A6; Axe santé des populations et pratiques optimales en santé, Centre de recherche du CHU de Québec, 2705 Boulevard Laurier, Québec Québec, Canada G1V 2L9; Direction de la santé environnementale et de la toxicologie, Institut national de santé publique du Québec, 945 Avenue Wolfe, Québec Québec, Canada G1V 5B3.
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Bove FJ, Ruckart PZ, Maslia M, Larson TC. Evaluation of mortality among marines and navy personnel exposed to contaminated drinking water at USMC base Camp Lejeune: a retrospective cohort study. Environ Health 2014; 13:10. [PMID: 24552493 PMCID: PMC3943370 DOI: 10.1186/1476-069x-13-10] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 02/11/2014] [Indexed: 05/28/2023]
Abstract
BACKGROUND Two drinking water systems at U.S. Marine Corps Base Camp Lejeune, North Carolina were contaminated with solvents during 1950s-1985. METHODS We conducted a retrospective cohort mortality study of Marine and Naval personnel who began service during 1975-1985 and were stationed at Camp Lejeune or Camp Pendleton, California during this period. Camp Pendleton's drinking water was uncontaminated. Mortality follow-up was 1979-2008. Standardized Mortality Ratios were calculated using U.S. mortality rates as reference. We used survival analysis to compare mortality rates between Camp Lejeune (N = 154,932) and Camp Pendleton (N = 154,969) cohorts and assess effects of cumulative exposures to contaminants within the Camp Lejeune cohort. Models estimated monthly contaminant levels at residences. Confidence intervals (CIs) indicated precision of effect estimates. RESULTS There were 8,964 and 9,365 deaths respectively, in the Camp Lejeune and Camp Pendleton cohorts. Compared to Camp Pendleton, Camp Lejeune had elevated mortality hazard ratios (HRs) for all cancers (HR = 1.10, 95% CI: 1.00, 1.20), kidney cancer (HR = 1.35, 95% CI: 0.84, 2.16), liver cancer (HR = 1.42, 95% CI: 0.92, 2.20), esophageal cancer (HR = 1.43 95% CI: 0.85, 2.38), cervical cancer (HR = 1.33, 95% CI: 0.24, 7.32), Hodgkin lymphoma (HR = 1.47, 95% CI: 0.71, 3.06), and multiple myeloma (HR = 1.68, 95% CI: 0.76, 3.72). Within the Camp Lejeune cohort, monotonic categorical cumulative exposure trends were observed for kidney cancer and total contaminants (HR, high cumulative exposure = 1.54, 95% CI: 0.63, 3.75; log10 β = 0.06, 95% CI: -0.05, 0.17), Hodgkin lymphoma and trichloroethylene (HR, high cumulative exposure = 1.97, 95% CI: 0.55, 7.03; β = 0.00005, 95% CI: -0.00003, 0.00013) and benzene (HR, high cumulative exposure = 1.94, 95% CI: 0.54, 6.95; β = 0.00203, 95% CI: -0.00339, 0.00745). Amyotrophic Lateral Sclerosis (ALS) had HR = 2.21 (95% CI: 0.71, 6.86) at high cumulative vinyl chloride exposure but a non-monotonic exposure-response relationship (β = 0.0011, 95% CI: 0.0002, 0.0020). CONCLUSION The study found elevated HRs at Camp Lejeune for several causes of death including cancers of the kidney, liver, esophagus, cervix, multiple myeloma, Hodgkin lymphoma and ALS. CIs were wide for most HRs. Because <6% of the cohort had died, long-term follow-up would be necessary to comprehensively assess effects of drinking water exposures at the base.
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Affiliation(s)
- Frank J Bove
- Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry (ATSDR), 4770 Buford Highway, MS F-58, Atlanta, GA 30341, USA
| | - Perri Zeitz Ruckart
- Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry (ATSDR), 4770 Buford Highway, MS F-58, Atlanta, GA 30341, USA
| | - Morris Maslia
- ATSDR, Division of Community Health Investigations, 4770 Buford Highway, MS F-59, Atlanta, GA 30341, USA
| | - Theodore C Larson
- Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry (ATSDR), 4770 Buford Highway, MS F-58, Atlanta, GA 30341, USA
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Krishnan K, Carrier R. The use of exposure source allocation factor in the risk assessment of drinking-water contaminants. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2013; 16:39-51. [PMID: 23573939 DOI: 10.1080/10937404.2013.769419] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In the risk assessment process, the reference dose, tolerable intake, or acceptable daily intake (RfD, TDI, ADI) is apportioned to specific exposure sources on the basis of a source allocation factor (AF) or relative source contribution (RSC). The U.S. Environmental Protection Agency (EPA) published an exposure decision tree framework in 2000 to guide the determination of AF (or RSC) of drinking-water contaminants (DWC). Besides that, there has not been any systematic analysis of the basis of the use of AF in DWC risk assessments. This article therefore critically reviews and integrates current knowledge and approaches for the development of AF, while focusing on its consistent use in DWC risk assessments based on consideration of (i) risk assessment endpoint, (ii) existing guidelines, (iii) exposure estimates, (iv) usage pattern and environmental fate information, (v) physicochemical properties, (vi) bounds of AF, (vii) multiroute exposures, and (viii) target population characteristics. Accordingly, for a DWC for which drinking water is not a major source of exposure and for which there is documented evidence of widespread presence in one or more of the other media (i.e., air, food, soil, or consumer products), the use of an AF value of 0.2 is suggested. For DWC for which drinking water represents nearly the single major source of exposure, a ceiling AF value of 0.8 is suggested. For other situations, chemical- and context-specific AF values can be developed based on exposure data or models, which should in turn be bounded by the floor and ceiling AF values as originally described by the U.S. EPA (i.e., 0.2-0.8). Future studies need to focus on improvements in methods for deriving AF, by basing it on the consideration of bioavailability, target tissue dose, and extent of route-specific absorption, as well as improvement in the modeling of dose received via direct/voluntary exposure through consumer products and at workplaces.
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Affiliation(s)
- Kannan Krishnan
- Département de santé environnementale et santé au travail, Université de Montréal, Montréal, Quebec, Canada.
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Ruiz P, Ray M, Fisher J, Mumtaz M. Development of a human Physiologically Based Pharmacokinetic (PBPK) Toolkit for environmental pollutants. Int J Mol Sci 2011; 12:7469-80. [PMID: 22174611 PMCID: PMC3233417 DOI: 10.3390/ijms12117469] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 10/13/2011] [Accepted: 10/24/2011] [Indexed: 11/17/2022] Open
Abstract
Physiologically Based Pharmacokinetic (PBPK) models can be used to determine the internal dose and strengthen exposure assessment. Many PBPK models are available, but they are not easily accessible for field use. The Agency for Toxic Substances and Disease Registry (ATSDR) has conducted translational research to develop a human PBPK model toolkit by recoding published PBPK models. This toolkit, when fully developed, will provide a platform that consists of a series of priority PBPK models of environmental pollutants. Presented here is work on recoded PBPK models for volatile organic compounds (VOCs) and metals. Good agreement was generally obtained between the original and the recoded models. This toolkit will be available for ATSDR scientists and public health assessors to perform simulations of exposures from contaminated environmental media at sites of concern and to help interpret biomonitoring data. It can be used as screening tools that can provide useful information for the protection of the public.
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Affiliation(s)
- Patricia Ruiz
- Computational Toxicology and Methods Development Laboratory, Division of Toxicology and Environmental Medicine, Agency for Toxic Substances and Disease Registry, Atlanta, GA 30333, USA; E-Mail:
| | - Meredith Ray
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; E-Mail:
| | - Jeffrey Fisher
- USFDA, National Center for Toxicological Research, Jefferson, AR 72079, USA; E-Mail:
| | - Moiz Mumtaz
- Computational Toxicology and Methods Development Laboratory, Division of Toxicology and Environmental Medicine, Agency for Toxic Substances and Disease Registry, Atlanta, GA 30333, USA; E-Mail:
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An assessment of the interindividual variability of internal dosimetry during multi-route exposure to drinking water contaminants. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2010; 7:4002-22. [PMID: 21139873 PMCID: PMC2996221 DOI: 10.3390/ijerph7114002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 11/04/2010] [Accepted: 11/12/2010] [Indexed: 12/14/2022]
Abstract
The objective of this study was to evaluate inter-individual variability in absorbed and internal doses after multi-route exposure to drinking water contaminants (DWC) in addition to the corresponding variability in equivalent volumes of ingested water, expressed as liter-equivalents (LEQ). A multi-route PBPK model described previously was used for computing the internal dose metrics in adults, neonates, children, the elderly and pregnant women following a multi-route exposure scenario to chloroform and to tri- and tetra-chloroethylene (TCE and PERC). This scenario included water ingestion as well as inhalation and dermal contact during a 30-min bathroom exposure. Monte Carlo simulations were performed and distributions of internal dose metrics were obtained. The ratio of each of the dose metrics for inhalation, dermal and multi-route exposures to the corresponding dose metrics for the ingestion of drinking water alone allowed computation of LEQ values. Mean BW-adjusted LEQ values based on absorbed doses were greater in neonates regardless of the contaminant considered (0.129–0.134 L/kg BW), but higher absolute LEQ values were obtained in average adults (3.6–4.1 L), elderly (3.7–4.2 L) and PW (4.1–5.6 L). LEQ values based on the parent compound’s AUC were much greater than based on the absorbed dose, while the opposite was true based on metabolite-based dose metrics for chloroform and TCE, but not PERC. The consideration of the 95th percentile values of BW-adjusted LEQ did not significantly change the results suggesting a generally low intra-subpopulation variability during multi-route exposure. Overall, this study pointed out the dependency of the LEQ on the dose metrics, with consideration of both the subpopulation and DWC.
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Buteau S, Valcke M. Probabilistic human health risk assessment for quarterly exposure to high chloroform concentrations in drinking-water distribution network of the Province of Quebec, Canada. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2010; 73:1626-1644. [PMID: 20967676 DOI: 10.1080/15287394.2010.501718] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Because quarterly concentrations of total trihalomethanes (THM) exceeding the 80 μg/L guideline are often tolerated by the public health authorities of the Province of Quebec (Canada), this study examined whether quarterly episodes of high concentrations of THM may pose a risk to the health of its population. Using Monte Carlo simulations, a probabilistic risk assessment was performed for infants (0-<6 mo), toddlers (6 mo-<5 yr) and adults (≥20 yr). Multiroute exposure including ingestion of drinking water as well as inhalation and dermal exposure while showering or bathing was considered. The resulting absorbed doses were compared to short-term reference values for chloroform, used as surrogate for THM, by calculating risk quotients (RQ). On the basis of THM concentrations values in Quebec's drinking water distribution systems during the months of July to October and exceeding the guideline value (>80 μg/L), the 95th percentile value of RQ were 0.65, 0.46, and 0.24 for infants, toddlers, and adults, respectively. Back-calculation allowed determining that a chloroform concentration of 330 μg/L would result in RQ ≤ 1 for 99% of infants, the subgroup considered the most susceptible among the general population. Overall, this study showed that episodes of high THM concentration encountered in Quebec drinking-water distribution network need not be considered as an immediate health concern for the general population. However, these results should not be interpreted as an authorization to exceed the 80 μg/L standard but rather as a risk management tool for public health authorities.
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Affiliation(s)
- Stephane Buteau
- Institut national de santé publique du Québec, Montréal, Québec, Canada
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