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Mian HR, Hu G, Hewage K, Rodriguez MJ, Sadiq R. Prioritization of unregulated disinfection by-products in drinking water distribution systems for human health risk mitigation: A critical review. WATER RESEARCH 2018; 147:112-131. [PMID: 30308371 DOI: 10.1016/j.watres.2018.09.054] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/24/2018] [Accepted: 09/27/2018] [Indexed: 06/08/2023]
Abstract
Water disinfection involves the use of different types of disinfectants, which are oxidizing agents that react with natural organic matter (NOM) to form disinfection by-products (DBPs). The United States Environmental Protection Agency (USEPA) has established threshold limits on some DBPs, which are known as regulated DBPs (R-DBPs). The human health risks associated with R-DBPs in drinking water distribution systems (DWDSs) and application of stricter regulations have led water utilities to switch from conventional disinfectant (i.e., chlorination) to alternative disinfectants. However, the use of alternative disinfectants causes formation of a new suit of DBPs known as unregulated DBPs (UR-DBPs), which in many cases can be more toxic. There is a growing concern of UR-DBPs formation in drinking water. This review prioritizes some commonly occurring UR-DBP groups and species in DWDSs based on their concentration level, reported frequency, and toxicity using an indexing method. There are nine UR-DBPs group and 36 species that have been identified based on recent published peer-reviewed articles. Haloacetonitriles (HANs) and haloacetaldehydes (HALs) are identified as important UR-DBP groups. Dichloroacetonitrile (DCAN) and trichloroacetaldehye (TCAL) are identified as critical UR-DBPs species. The outcomes of this review can help water regulators to identify the most critical UR-DBPs species in the context of drinking water safety and provide them with useful information to develop guidelines or threshold limits for UR-DBPs. The outcomes can also help water utilities in selecting water treatment processes for the mitigation of human health risk posed by UR-DBPs through drinking water.
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Affiliation(s)
- Haroon R Mian
- School of Engineering, The University of British Columbia, Okanagan 3333 University Way, Kelowna, BC, V1V 1V7, Canada
| | - Guangji Hu
- School of Engineering, The University of British Columbia, Okanagan 3333 University Way, Kelowna, BC, V1V 1V7, Canada
| | - Kasun Hewage
- School of Engineering, The University of British Columbia, Okanagan 3333 University Way, Kelowna, BC, V1V 1V7, Canada
| | - Manuel J Rodriguez
- École Supérieure D'aménagement du Territoire et Développement Régional (ESAD), 2325, allée des Bibliothèque Université Laval, Québec City, QC, G1V 0A6, Canada
| | - Rehan Sadiq
- School of Engineering, The University of British Columbia, Okanagan 3333 University Way, Kelowna, BC, V1V 1V7, Canada.
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52
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New insights on occupational exposure and bladder cancer risk: a pooled analysis of two Italian case–control studies. Int Arch Occup Environ Health 2018; 92:347-359. [DOI: 10.1007/s00420-018-1388-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 11/24/2018] [Indexed: 10/27/2022]
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53
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Cancer incidence and all-cause mortality among civilian men and women employed by the Royal Norwegian Navy between 1950 and 2005. Cancer Epidemiol 2018; 57:1-6. [PMID: 30205311 DOI: 10.1016/j.canep.2018.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 08/01/2018] [Accepted: 08/29/2018] [Indexed: 11/20/2022]
Abstract
OBJECTIVE We aimed to investigate cancer incidence and all-cause mortality in a cohort of 8358 civilians (5134 men and 3224 women) employed by the Royal Norwegian Navy at any time between 1950 and 2005. METHODS The cohort was followed for cancer incidence and all-cause mortality from 1960 through 2015. Standardised incidence ratios (SIR) and mortality ratios (SMR) were calculated from national rates. Separate SIRs were calculated for a subgroup of male workshop workers and another of female cleaners. RESULTS Overall cancer incidence among men was similar to the reference rate; male breast cancer was more frequent (SIR = 3.23). Male workshop workers showed a SIR of 1.77 for stomach cancer, while their incidence of lympho-haematopoietic cancers was half that of the reference rates. Women had increased risks of overall cancer (SIR = 1.11), lung cancer (SIR = 1.35), and ovarian cancer (SIR = 1.39). Female cleaners showed a SIR of 2.33 for bladder cancer and a lowered incidence of brain cancer (SIR = 0.18). In the overall cohort, all-cause mortality was lower than expected for men (SMR = 0.92) and closer to the reference rate for women (SMR = 0.95). CONCLUSION In men, we observed a lowered all-cause mortality and an excess of stomach cancer in workshop workers. In women, increased risks of overall cancer, lung cancer and ovarian cancer was seen. An increased risk of bladder cancer and a lowered incidence of brain cancer was observed among female cleaners.
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Cortés C, Marcos R. Genotoxicity of disinfection byproducts and disinfected waters: A review of recent literature. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2018; 831:1-12. [DOI: 10.1016/j.mrgentox.2018.04.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/22/2018] [Accepted: 04/23/2018] [Indexed: 10/17/2022]
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Marsà A, Cortés C, Hernández A, Marcos R. Hazard assessment of three haloacetic acids, as byproducts of water disinfection, in human urothelial cells. Toxicol Appl Pharmacol 2018; 347:70-78. [DOI: 10.1016/j.taap.2018.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 03/30/2018] [Accepted: 04/03/2018] [Indexed: 12/26/2022]
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56
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Wang W, Qian Y, Li J, Aljuhani N, Siraki AG, Le XC, Li XF. Characterization of Mechanisms of Glutathione Conjugation with Halobenzoquinones in Solution and HepG2 Cells. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:2898-2908. [PMID: 29420883 DOI: 10.1021/acs.est.7b05945] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Halobenzoquinones (HBQs) are a class of emerging disinfection byproducts. Chronic exposure to chlorinated drinking water is potentially associated with an increased risk of human bladder cancer. HBQ-induced cytotoxicity involves depletion of cellular glutathione (GSH), but the underlying mechanism remains unclear. Here we used ultrahigh performance liquid chromatography-high resolution mass spectrometry and electron paramagnetic resonance spectroscopy to study interactions between HBQs and GSH and found that HBQs can directly react with GSH, forming various glutathionyl conjugates (HBQ-SG) in both aqueous solution and HepG2 cells. We found that the formation of HBQ-SG varies with the initial molar ratio of GSH to HBQ in reaction mixtures. Higher molar ratios of GSH to HBQ facilitate the conjugation of more GSH molecules to an HBQ molecule. We deduced the reaction mechanism between GSH and HBQs, which involves redox cycling-induced formation of halosemiquinone (HSQ) free radicals and glutathione disulfide, Michael addition, as well as nucleophilic substitution. The proposed reaction rates are in the following order: formation of HSQ radicals > substitution of bromine by GSH > Michael addition of GSH on the benzoquinone ring > substitution of chlorine by GSH > substitution of the methyl group by GSH. The conjugates identified in HBQ-treated HepG2 cells were the same as those found in aqueous solution containing a 5:1 ratio of GSH:HBQs.
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Affiliation(s)
- Wei Wang
- Department of Environmental Science , Zhejiang University , Hangzhou , Zhejiang 310058 , China
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta T6G 2G3 , Canada
| | - Yichao Qian
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta T6G 2G3 , Canada
| | - Jinhua Li
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta T6G 2G3 , Canada
| | - Naif Aljuhani
- Faculty of Pharmacy and Pharmaceutical Sciences , University of Alberta , Edmonton , Alberta T6G 2H7 , Canada
| | - Arno G Siraki
- Faculty of Pharmacy and Pharmaceutical Sciences , University of Alberta , Edmonton , Alberta T6G 2H7 , Canada
| | - X Chris Le
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta T6G 2G3 , Canada
- Department of Chemistry, Faculty of Science , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Xing-Fang Li
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta T6G 2G3 , Canada
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57
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Jiang P, Huang G, Jmaiff Blackstock LK, Zhang J, Li XF. Ascorbic Acid Assisted High Performance Liquid Chromatography Mass Spectrometry Differentiation of Isomeric C-Chloro- and N-Chloro-Tyrosyl Peptides in Water. Anal Chem 2017; 89:13642-13650. [DOI: 10.1021/acs.analchem.7b04262] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Ping Jiang
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
| | - Guang Huang
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
| | - Lindsay K. Jmaiff Blackstock
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
| | - Jianye Zhang
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
- College
of Chemistry and Molecular Engineering, Zhengzhou University, Henan, People’s Republic of China, 450052
| | - Xing-Fang Li
- Division
of Analytical and Environmental Toxicology, Department of Laboratory
Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta Edmonton, Alberta Canada T6G 2G3
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In vitro studies on the tumorigenic potential of the halonitromethanes trichloronitromethane and bromonitromethane. Toxicol In Vitro 2017; 45:72-80. [DOI: 10.1016/j.tiv.2017.08.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/22/2017] [Accepted: 08/21/2017] [Indexed: 12/27/2022]
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Kolb C, Francis RA, VanBriesen JM. Disinfection byproduct regulatory compliance surrogates and bromide-associated risk. J Environ Sci (China) 2017; 58:191-207. [PMID: 28774609 DOI: 10.1016/j.jes.2017.05.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/15/2017] [Accepted: 05/31/2017] [Indexed: 06/07/2023]
Abstract
Natural and anthropogenic factors can alter bromide concentrations in drinking water sources. Increasing source water bromide concentrations increases the formation and alters the speciation of disinfection byproducts (DBPs) formed during drinking water treatment. Brominated DBPs are more toxic than their chlorinated analogs, and thus have a greater impact on human health. However, DBPs are regulated based on the mass sum of DBPs within a given class (e.g., trihalomethanes and haloacetic acids), not based on species-specific risk or extent of bromine incorporation. The regulated surrogate measures are intended to protect against not only the species they directly represent, but also against unregulated DBPs that are not routinely measured. Surrogates that do not incorporate effects of increasing bromide may not adequately capture human health risk associated with drinking water when source water bromide is elevated. The present study analyzes trihalomethanes (THMs), measured as TTHM, with varying source water bromide concentrations, and assesses its correlation with brominated THM, TTHM risk and species-specific THM concentrations and associated risk. Alternative potential surrogates are evaluated to assess their ability to capture THM risk under different source water bromide concentration conditions. The results of the present study indicate that TTHM does not adequately capture risk of the regulated species when source water bromide concentrations are elevated, and thus would also likely be an inadequate surrogate for many unregulated brominated species. Alternative surrogate measures, including THM3 and the bromodichloromethane concentration, are more robust surrogates for species-specific THM risk at varying source water bromide concentrations.
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Affiliation(s)
- Chelsea Kolb
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Royce A Francis
- Department of Engineering Management and Systems Engineering, The George Washington University, Washington, DC 20052, USA
| | - Jeanne M VanBriesen
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA; Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
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60
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Komaki Y, Plewa MJ. Investigation of nuclear enzyme topoisomerase as a putative molecular target of monohaloacetonitrile disinfection by-products. J Environ Sci (China) 2017; 58:231-238. [PMID: 28774614 DOI: 10.1016/j.jes.2017.04.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/17/2017] [Accepted: 04/20/2017] [Indexed: 05/08/2023]
Abstract
Disinfection by-products occur widely as the unintended effect of water disinfection and are associated with toxicity and adverse human health effects. Yet the molecular mechanisms of their toxicity are not well understood. To investigate the molecular basis of hyperploidy induction by monohaloacetonitriles, the interaction of monohaloacetonitriles with topoisomerase II in Chinese hamster ovary cells was examined. We showed a concentration-dependent inhibition of DNA decatenation activity of topoisomerase under acellular conditions while in vitro monohaloacetonitrile treatment expressed mixed results. The working hypothesis, that topoisomerase II is a molecular target of monohaloacetonitriles, was only partially supported. Nevertheless, this research serves as a starting point toward molecular mechanisms of toxic action of monohaloacetonitriles.
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Affiliation(s)
- Yukako Komaki
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Safe Global Water Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
| | - Michael J Plewa
- Safe Global Water Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
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61
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Liu Q, Liao B, Tian Y, Chen Y, Luo D, Lin Y, Li H, Wang KJ. Total fluid consumption and risk of bladder cancer: a meta-analysis with updated data. Oncotarget 2017; 8:55467-55477. [PMID: 28903434 PMCID: PMC5589673 DOI: 10.18632/oncotarget.18100] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 05/04/2017] [Indexed: 02/05/2023] Open
Abstract
With meta-analysis we tented to reveal the potential relationship between daily fluid consumption and bladder cancer risk, and to find out a recommendation on daily fluid intake. Databases of the Web of Science, PubMed and EMBASE were searched then 21 case-control and 5 cohort studies were included. Stratified analyses on gender, region, time of subjects recruiting and fluid quantity were performed as well as dose-response meta-analysis. Comparing the highest exposure category with the lowest in each study, no association appeared when all data pooled together (p=0.50), but a significant OR of 1.46 (1.02-2.08, p=0.04) was found in male subgroup. For different regions, the summarized OR was 1.44 (1.10-1.89) in American case-control studies, 1.87 (1.20-2.90) in European male subgroup and 0.24 (0.10-0.60) in Asia. There was a significant relationship that each increment 1000ml daily consumption would increase the risk by 28.6% in European male (p=0.007). Similarly every additional 1000ml consumption may increase the OR by 14.9% in American people but the association wasn't that strong (p=0.057). Stratified analyses showed fluid consumption over 3000ml/day in American residents and 2000ml/day in European male resulted in OR>1 with statistical significance. In conclusion, a relationship between higher fluid intake and higher bladder cancer risk was observed in European male and American residents and a limitation to <2000ml and <3000ml per day are recommended respectively.
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Affiliation(s)
- Qinyu Liu
- Urology Department, Institute of Urology (Laboratory of Reconstructive Urology), West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Banghua Liao
- Urology Department, Institute of Urology (Laboratory of Reconstructive Urology), West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ye Tian
- Urology Department, Guizhou Provincial People's Hospital, Guiyang, Guizhou, China
| | - Yuntian Chen
- Urology Department, Institute of Urology (Laboratory of Reconstructive Urology), West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Deyi Luo
- Urology Department, Institute of Urology (Laboratory of Reconstructive Urology), West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yifei Lin
- Urology Department, Institute of Urology (Laboratory of Reconstructive Urology), West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hong Li
- Urology Department, Institute of Urology (Laboratory of Reconstructive Urology), West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Kun-Jie Wang
- Urology Department, Institute of Urology (Laboratory of Reconstructive Urology), West China Hospital, Sichuan University, Chengdu, Sichuan, China
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Potential Health Benefits of Deep Sea Water: A Review. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2016; 2016:6520475. [PMID: 28105060 PMCID: PMC5221345 DOI: 10.1155/2016/6520475] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/27/2016] [Indexed: 02/06/2023]
Abstract
Deep sea water (DSW) commonly refers to a body of seawater that is pumped up from a depth of over 200 m. It is usually associated with the following characteristics: low temperature, high purity, and being rich with nutrients, namely, beneficial elements, which include magnesium, calcium, potassium, chromium, selenium, zinc, and vanadium. Less photosynthesis of plant planktons, consumption of nutrients, and organic decomposition have caused lots of nutrients to remain there. Due to this, DSW has potential to become a good source for health. Research has proven that DSW can help overcome health problems especially related to lifestyle-associated diseases such as cardiovascular disease, diabetes, obesity, cancer, and skin problems. This paper reviews the potential health benefits of DSW by referring to the findings from previous researches.
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63
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Yang L, Schmalz C, Zhou J, Zwiener C, Chang VWC, Ge L, Wan MP. An insight of disinfection by-product (DBP) formation by alternative disinfectants for swimming pool disinfection under tropical conditions. WATER RESEARCH 2016; 101:535-546. [PMID: 27300590 DOI: 10.1016/j.watres.2016.05.088] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/13/2016] [Accepted: 05/28/2016] [Indexed: 06/06/2023]
Abstract
Sodium hypochlorite (NaClO) is the most commonly used disinfectant in pool treatment system. Outdoor pools usually suffer from the strong sunlight irradiation which degrades the free chlorine rapidly. In addition, more pools start to adopt the recirculation of swimming pool water, which intensifies the disinfection by-product (DBP) accumulation issue. Given these potential drawbacks of using NaClO in the tropical environment, two alternative organic-based disinfectants, trichloroisocyanuric acid (TCCA, C3Cl3N3O3) and bromochlorodimethylhydantoin (BCDMH, C5H6BrClN2O2), were investigated and compared to NaClO in terms of their self-degradation and the formation of DBPs, including trihalomethanes (THMs) and haloacetic acids (HAAs), under simulated tropical climate conditions. The result reveals that halogen stabilizer, TCCA, had the advantages of slower free chlorine degradation and lower DBP concentration compared to NaClO, which makes it a good alternative disinfectant. BCDMH was not recommended mainly due to the highly reactive disinfecting ingredient, hypobromous acid (HBrO), which fails to sustain the continuous disinfection requirement. Total disinfectant dosage was the main factor that affects residual chlorine/bromine and THM/HAA formation regardless of different disinfectant dosing methods, e.g. shock dosing (one-time spiking) in the beginning, and continuous dosing during the whole experimental period. Two-stage second-order-kinetic-based models demonstrate a good correlation between the measured and predicted data for chlorine decay (R(2) ≥ 0.95), THM (R(2) ≥ 0.99) and HAA (R(2) ≥ 0.83) formation. Higher temperature was found to enhance the DBP formation due to the temperature dependence of reaction rates. Thus, temperature control of pools, especially for those preferring higher temperatures (e.g. hydrotherapy and spa), should take both bather comfort and DBP formation potential into consideration. It is also observed that chlorine competition existed between different precursors from natural organic matters (NOM) in filling water and body fluid analogue (BFA). Among the composition of BFA, uric acid, citric acid and hippuric acid were found to be the main precursors for HAA formation.
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Affiliation(s)
- Linyan Yang
- Interdisciplinary Graduate School, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; Residues and Resource Reclamation Centre (R3C), Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore
| | - Christina Schmalz
- Environmental Analytical Chemistry, Center for Applied Geoscience (ZAG), Eberhard Karls University Tuebingen, 72076 Tuebingen, Germany
| | - Jin Zhou
- Division of Environmental and Water Resources, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Christian Zwiener
- Environmental Analytical Chemistry, Center for Applied Geoscience (ZAG), Eberhard Karls University Tuebingen, 72076 Tuebingen, Germany
| | - Victor W-C Chang
- Residues and Resource Reclamation Centre (R3C), Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore; Division of Environmental and Water Resources, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
| | - Liya Ge
- Residues and Resource Reclamation Centre (R3C), Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore
| | - Man Pun Wan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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Li J, Moe B, Vemula S, Wang W, Li XF. Emerging Disinfection Byproducts, Halobenzoquinones: Effects of Isomeric Structure and Halogen Substitution on Cytotoxicity, Formation of Reactive Oxygen Species, and Genotoxicity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:6744-6752. [PMID: 26812484 DOI: 10.1021/acs.est.5b05585] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Halobenzoquinones (HBQs) are a structurally diverse class of water disinfection byproducts. Here, we report a systematic study on the effects of isomeric structure and the type and number of halogen substitutions of HBQs on their cytotoxicity, formation of reactive oxygen species (ROS), and genotoxicity. Dynamic responses and IC50 histograms were obtained using real-time cell analysis, clearly ranking the cytotoxicity of the HBQs in Chinese hamster ovary (CHO-K1) cells. Strong isomeric structure effects were shown with 2,5-HBQ isomers inducing greater cytotoxicity than their corresponding 2,6-HBQ isomers (P < 0.05). HBQ-halogen substitution groups also influence cytotoxicity, as cytotoxicity increases across the dihalogenated HBQs: iodo- > bromo- > chloro-HBQs (P < 0.05). Determination of HBQ-induced ROS further supports isomeric structure and halogen substitution effects. HBQ-induced genotoxicity was shown as increased levels of 8-hydroxy-2'-deoxyguanosine and p53 protein. Pearson correlation analysis of the HBQ toxicity measurements with their physicochemical parameters demonstrates that dipole moment and the lowest unoccupied molecular orbital energy are two major structural influences on toxicity (r = -0.721 or -0.766, P < 0.05). Dipole moment also correlates with isomer toxicity. This study suggests that formation and occurrence of highly toxic iodo-HBQs and 2,5-HBQs warrant further investigation to fully assess the impact of HBQs in drinking water.
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Affiliation(s)
- Jinhua Li
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G3
| | - Birget Moe
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G3
| | - Sai Vemula
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G3
| | - Wei Wang
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G3
| | - Xing-Fang Li
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G3
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65
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Phetxumphou K, Dietrich AM, Shanaiah N, Smiley E, Gallagher DL. Subtleties of human exposure and response to chemical mixtures from spills. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 214:618-626. [PMID: 27131822 DOI: 10.1016/j.envpol.2016.04.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 04/14/2016] [Accepted: 04/15/2016] [Indexed: 06/05/2023]
Abstract
Worldwide, chemical spills degrade drinking water quality and threaten human health through ingestion and inhalation. Spills are often mixtures of chemicals; thus, understanding the interaction of chemical and biological properties of the major and minor components is critical to assessing human exposure. The crude (4-methylcyclohexyl)methanol (MCHM) spill provides an opportunity to assess such subtleties. This research determined the relative amounts, volatilization, and biological odor properties of minor components cis- and trans-methyl-4-methylcyclohexanecarboxylate (MMCHC) isomers and major components cis- and trans-4-MCHM, then compared properties and human exposure differences among them. (1)H nuclear magnetic resonance and chromatography revealed that the minor MMCHC isomers were about 1% of the major MCHM isomers. At typical showering temperature of 40 °C, Henry's law constants were 1.50 × 10(-2) and 2.23 × 10(-2) for cis- and trans-MMCHC, respectively, which is 20-50 fold higher than for 4-MCHM isomers. The odor thresholds were 1.83 and 0.02 ppb-v air for cis- and trans-MMCHC, which were both described as predominantly sweet. These data are compared to the higher 120 ppb-v air and 0.06 ppb-v odor thresholds for cis- and trans-4-MCHM, for which the trans-isomer had a dominant licorice descriptor. Application of a shower model demonstrated that while MMCHC isomers are only about 1% of the MCHM isomers, during showering, the MMCHC isomers are 13.8% by volume (16.3% by mass) because of their higher volatility. Trans-4-MCHM contributed about 82% of the odor because of higher volatility and lower odor threshold, trans-MMCHC, which represents 0.3% of the mass, contributed 18% of the odor. This study, with its unique human sensory component to assess exposure, reaffirmed that hazard assessment must not be based solely on relative concentration, but also consider the chemical fate, transport, and biological properties to determine the actual levels of exposure across different media.
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Affiliation(s)
- Katherine Phetxumphou
- Civil and Environmental Engineering, 413 Durham Hall, MC0246, 1145 Perry Street, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Andrea M Dietrich
- Civil and Environmental Engineering, 413 Durham Hall, MC0246, 1145 Perry Street, Virginia Tech, Blacksburg, VA 24061, USA.
| | | | - Elizabeth Smiley
- Civil and Environmental Engineering, 413 Durham Hall, MC0246, 1145 Perry Street, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Daniel L Gallagher
- Civil and Environmental Engineering, 413 Durham Hall, MC0246, 1145 Perry Street, Virginia Tech, Blacksburg, VA 24061, USA.
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