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# What is in Our Drinking Water?

Identification of New Chemical Disinfection By - products (DBPs)

What is a DBP? A drinking water disinfection by - product (DBP) is formed when the chemical used for disinfecting the drinking water reacts withnatural organic matter and/or bromide/iodide in the source water. Populardisinfectants include chlorine, ozone, chlorine dioxide, and chloramine. Source waters include rivers, lakes, streams, groundwater, and sometimes seawater. We have only known about DBPs since 1974, when chloroform was identified by Rook as a DBP resulting from the chlorination of tap water. Since then, hundreds of DBPs have been identified in drinking water. So what? Millions of people in the U.S. are exposed to these drinking water DBPs every day. While it is vitally important to disinfect

drinking water, as thousands of people died from waterborne illnesses before we started disinfection practices in the early 1900s, it is also important to minimize the chemical DBPs formed. Several DBPs have been linked to cancer in laboratory animals, and as a result, the U.S. EPA has some of these DBPs regulated. However, there are many more DBPs that have still not beenidentified and tested for toxicity or cancer effects. Currently, we have only identified about 50% of the total organic halide (TOX) that is measured inchlorinated drinking water. There is much less known about DBPs from the newer alternative disinfectants, such as ozone, chlorine dioxide, andchloramine, which are gaining in popularity in the U.S. Are these alternative disinfectants safer than chlorine? What kinds of by - products are formed? And, what about the unidentified chlorine DBPs that people are exposed to through their drinking water -- both from drinking and showering/bathing? The objective of our research is to find out what these DBPs are -- to thoroughly characterize the Picture of a little girl drinking w ater 1. 2. All EPA This Area Advanced Search            Learn the Issues Science & Technology Laws & Regulations About EPA Page 1 of 7 Drinking Water | Ecosystems Research Division | US EPA

11/18/2010 file://C:\Program Files\Documentum\CTS\docbases\ProDocbase\config\temp_sessions\4902004198101473791\ ...chemicals formed in drinking water treatment -- and to ultimately minimize any harmful ones that are formed. Our research approach

 Gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), and gas chromatography/infrared spectroscopy (GC/IR) techniques are used to identify the unknown by - products

 NIST and Wiley mass spectral databases are used first to identify any DBPs that happen to be present in these databases

 Because many DBPs are not in these databases, most of our work involves unconventional MS and IR techniques, as well as a great deal of scientific interpretation of the spectra

 High resolution MS provides empirical formula information for the unknownchemical (e.g., how many carbons, hydrogens, oxygens, nitrogens, etc. are inthe chemical ’ s structure)

 Chemical ionization MS provides molecular weight information when this is not provided in conventional electron ionization mass spectra

 IR spectroscopy provides functional group information (e.g., whether the oxygens are due to a carboxylic acid group, a ketone, an alcohol, or analdehyde)

 LC/MS is used to identify compounds that cannot be extracted from water(the highly polar, hydrophilic ones), as well as the high molecular weight, nonvolatile DBPs. This is a major missing gap in our knowledge aboutDBPs -- so far, most DBPs identified have been those that are easily extracted from water and are volatile enough to analyze by GC/MS

 Novel derivatization techniques are also applied to aid in the identification of highly polar DBPs

 Formation and fate & transport studies are conducted to better understand how certain priority DBPs are formed and transformed in treatmentand distribution systems Currently We recently completed an iodo - DBP occurrence study (published in the Nov. 15, 2008 issue of Environmental Science & Technology; ES&T 2008, 42 (22), 8330 - 8338) that involved the measurement of iodo - acid DBPs and iodo - THMs in drinking waters from 23 cities across the U.S. and Canada, and the study of their genotoxicity and cytotoxicity. We identified the iodo - acids for the first time as part of a large nationwide occurrence study of priority DBPs (mentioned below), and they are important because iodoacetic acid was found to be highly genotoxic (to mammalian cells), and it is more genotoxic than the regulated chloro/bromo - haloacetic acids (ES&T 2004, 38 (18): 4713 - 4722). This study helped to underscore the increased formation of

iodo - DBPs with chloramination, which is an increasingly popular disinfectantused in the U.S. The first phase of the Four Lab Study was also published recently (see special issue of Journal of Toxicology and Environmental Health, Part A, October22, 2008 issue), where we combined chemical and toxicological characterization (with an emphasis on newer reproductive and developmental effects) of complex DBP mixtures. This study is called the Four Lab Study because it involves the collaboration of scientists from the four national laboratories/centers of the U.S. EPA: The National Health and Environmental Effects ResearchLaboratory, the National Exposure Research Laboratory, the National RiskManagement Research Laboratory, and the National Center for Environmental Assessment. The Four Lab Study serves to address potential health concerns that cannot be addressed directly by the toxicological study of individual DBPs or defined DBP mixtures, and in essence, provides toxicological information for the complete drinking water mixture: both the known DBPs, as well as the unidentified fraction of DBPs. Drinking water treated with chlorine orozone - chlorine was concentrated by reverse osmosis to maintain a water matrix suitable for the animal studies. The next phase of this work is also nearing completion and included a larger battery of toxicological endpoints and focused on chlorinated drinking water. Page 2 of 7 Drinking Water | Ecosystems Research Division | US EPA

11/18/2010 file://C:\Program Files\Documentum\CTS\docbases\ProDocbase\config\temp_sessions\4902004198101473791\ ...Our earlier nationwide DBP occurrence study was published in ES&T in the Dec. 1, 2006 issue (ES&T, 2006, 40, 7175 - 7185), and can also be found in its full 400+ page report at EPA/600/R - 02/068 . This large study involved the sampling of drinking waters across the U.S. (disinfected with the different disinfectants and with different water quality, including elevated levels of bromide in the source water). A group of >50 DBPs that resulted from a prioritization of >500 DBPs in the literature for predicted adverse health effects was quantified in these drinking waters. Fate and transport studies were also conducted in the drinking water distribution systems to determine whether these DBPs changed in concentration or were transformed in the distribution systems. In addition to obtaining important quantitative information on these new DBPs (to help inprioritizing health effects testing), important new discoveries were made regarding the use of alternative disinfectants. While the use of alternative disinfectants lowered the levels of the four regulatedtrihalomethanes and five haloacetic acids (as compared to chlorine), many of the other prioritized DBPs were formed at higher levels with these alternative disinfectants. For example, the highest levels of iodinated DBPs were found in chloraminated drinking water, the highest levels of halonitromethanes were found in pre - ozonated drinking water, and dihaloaldehydes were highest at aplant using chloramines and ozone. Our new work includes investigating other potential sources of iodine in the formation of iodo - DBPs and investigating the influence of the length of free chlorine contact time (before ammonia addition to form chloramines) on their formation. In other research, a toxicity - based identification approach(using mammalian cell and medaka fish assays) is being used to focus identification efforts on the most toxic drinking water fractions, with anemphasis on obtaining new information on high molecular weight DBPs (which are believed to make up approximately 50% of the halogenated DBPs produced). Recent results

 A recent iodo - DBP occurrence study (ES&T 2008, 42 (22), 8330 - 8338) has provided the first quantitative occurrence data for highly genotoxic iodo - acid DBPs and information on their formation (along with iodo - THMs) in chloraminated drinking water, along with the first toxicity data for iodo - THMs and iodo - acids (beyond the first work on iodoacetic acid)

 The first phase of the Four Lab Study (Environ. Toxicol. Health, Pt. A, 2008, 71, 1125 - 1132 and following papers in this issue) reports results froman integrated chemical/toxicological research study to investigate the toxicological effects of complex DBP mixtures

 A Nationwide DBP Occurrence Study (ES&T, 2006, 40, 7175 - 7185) providedimportant new quantitative information on unregulated DBPs that have the potential to cause adverse health effects based on a structure - activity analysis (Woo et al., 2002); several of these DBPs have concentrations similar to some that are already regulated

 The use of alternative disinfectants can produce higher levels of these DBPs, as compared to chlorine

 Collaborations are ongoing with health effects researchers to studyselected DBPs for potential adverse health effects Gordon Research Conference on DBPs The second Gordon Research Conference on drinking water DBPs was held August9 - 14, 2009, at Mount Holyoke College in South Hadley, Massachusetts. Like the first one initiated in 2006 (where scientists from 22 countries came), this conference brought together scientists from different disciplines: chemists, toxicologists, epidemiologists, engineers, clinicians, human exposure scientists, risk assessors, and regulators to address the issues with drinking water DBPs. Ben Blount from the Centers for Disease Control and Prevention(CDC) was the Chair of the 2009 conference, and Manolis Kogevinas from Centre for Research in Environmental Epidemiology (CREAL) and the Municipal Institute of Medical Research (IMIM Hospital del Mar) in Barcelona, Spain will be the nextchair of the upcoming 2012 conference Contact Susan Richardson ( richardson.susan@epa.gov ) or Manolis Kogevinas (kogevinas@creal.cat) for more information. Useful publications Page 3 of 7 Drinking Water | Ecosystems Research Division | US EPA

11/18/2010 file://C:\Program Files\Documentum\CTS\docbases\ProDocbase\config\temp_sessions\4902004198101473791\ ...LaKind, J. S., S. D. Richardson, B. C. Blount. 2010. The good, the bad, and the volatile

– Can we have both healthy pools and healthy people? Environ. Sci. Technol ., in press. Richardson, S. D. 2009. Water Analysis: Emerging Contaminants and Current Issues. Anal. Chem ., 81(12): 4645 - 4677. (Invited biennial reviewarticle). Weisel, C. P., S. D. Richardson, B. Nemery, G. Aggazzotti, E. Baraldi, E. R. Blatchley, III, B. C. Blount, K - H. Carlsen, P. A. Eggleston, F. H. Frimmel, M. Goodman, G. Gordon, S. A. Grinshpun, D. Heederik, M. Kogenvinas, J. S. LaKind, M. J. Nieuwenhuijsen, F. C. Piper, S. A. Sattar. 2009. ChildhoodAsthma and Environmental Exposures at Swimming Pools: State of the Science and Research Recommendations. Environ. Health Perspect. , 117 (4): 500 - 507. Richardson, S. D. 2009. Disinfection By - Products and Drinking Water Treatment. In Drinking Water

– Sources, Sanitation and Safeguarding . Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning: Stockholm Sweden. (Invited book chapter for World Water Weekbook). Richardson, S. D., C. Rav - Acha, and G. D. Simpson. 2009. Chlorine Dioxide Chemistry, Reactions, and Disinfection By Products. In State of

the Science of Chlorine Dioxide in Drinking Water, Water Research Foundationand Fondazione AMGA: Denver, CO. (Invited book chapter). Richardson, S. D., F. Fasano, J. J. Ellington, F. G. Crumley, K. M. Buettner, J. J. Evans, B. C. Blount, L. K. Silva, T. J. Waite, G. W. Luther, A. B. McKague, R. J. Miltner, E. D. Wagner, and M. J. Plewa. 2008. Occurrence and Mammalian Cell Toxicity of Iodinated Disinfection Byproducts inDrinking Water. Environ. Sci. Technol ., 42 (22): 8330 - 8338. Plewa, M. J., M. G. Muellner, S. D. Richardson, F. Fasano, K. M. Buettner, Y. - T. Woo, A. B. McKague, and E. D. Wagner. 2008. Occurrence, Synthesis, and Genotoxicity of Haloacetamides: An Emerging Class of Nitrogenous Drinking Water Disinfection Byproducts. Environ. Sci. Technol. , 42 (3), 955 - 961. Richardson, S. D., A. D. Thruston, Jr., S. W. Krasner, H. S. Weinberg, R. J. Miltner, M. G. Narotsky, and J. E. Simmons. 2008. IntegratedDisinfection Byproducts Mixtures Research: Comprehensive Characterization of Water Concentrates Prepared from Chlorinated and Ozonated/PostchlorinatedDrinking Water. J. Toxicol. Environ. Health , Pt. A, 71: 1165 - 1186. Simmons, J. E., S. D. Richardson, T. F. Speth, R. J. Miltner, G. Rice, K. M. Schenck, E. S. Hunter, III, and L. K. Teuschler. 2008. Research Issues Underlying the Four - Lab Study: Integrated Disinfection Byproducts Mixtures Research. J. Toxicol. Environ. Health , Pt. A, 71: 1125 - 1132. Miltner, R. J., T. F. Speth, S. D. Richardson, S. W. Krasner, H. S. Weinberg, and J. E. Simmons. 2008. Integrated Disinfection Byproducts Mixtures Research: Disinfection of Drinking Waters by Chlorination and Ozonation/Postchlorination Treatment Scenarios. J. Toxicol. Environ. Health , Pt. A, 71: 1133 - 1148. Speth, T. F., R. J. Miltner, S. D. Richardson, and J. E. Simmons. 2008. Integrated Disinfection Byproducts Mixtures Research: Concentration by Reverse Osmosis Membrane Techniques of Disinfection Byproducts from Water Disinfected by Chlorination and Ozonation/Postchlorination. J. Toxicol. Environ. Health , Pt. A, 71: 1149 - 1164. Rice, G., L. K. Teuschler, S. D. Richardson, T. F. Speth, and J. E. Simmons. 2008. Integrated Disinfection Byproducts Mixtures Research: Assessing Reproductive and Developmental Risks Posed by Complex DisinfectionByproduct Mixtures. J. Toxicol. Environ. Health , Pt. A, 71: 1222 - 1234. Richardson. S. D. 2008. Environmental Mass Spectrometry: Emerging Contaminants and Current Issues. Anal. Chem ., 80 (12): 4373 - 4402. Richardson, S. D., M. J. Plewa, E. D. Wagner, R. Schoeny, and D. M. DeMarini. Occurrence, Genotoxicity, and Carcinogenicity of Emerging Disinfection By - Products in Drinking Water: A Review and Roadmap for Research. 2007. Mutat. Res ., 636: 178 - 242. Page 4 of 7 Drinking Water | Ecosystems Research Division | US EPA

11/18/2010 file://C:\Program Files\Documentum\CTS\docbases\ProDocbase\config\temp_sessions\4902004198101473791\ ...Muellner, M. G., E. D. Wagner, K. McCalla, S. D. Richardson, Y. - T. Wood, and M. J. Plewa. 2007. Haloacetonitriles vs. Regulated Haloacetic Acids: Are Nitrogen Containing DBPs More Toxic? Environ. Sci. Technol., 41 (2): 645 - 651. Zwiener, C., S. D. Richardson, D. M. DeMarini, T. Grummt, T. Glauner, and F. H. Frimmel. 2007. Drowining in Disinfection By - Products? Swimming Pool Water Quality Reconsidered. Environ. Sci. Technol ., 41 (2): 363 - 372. Plewa, M. J., M. G. Muellner, S. D. Richardson, F. Fasano, K. M. Buettner, Y. - T. Woo, A. B. McKague, and E. D. Wagner. 2007. Occurrence, Synthesis, and Mammalian Cell Cytotoxicity and Genotoxicity of Haloacetamides: An Emerging Class of Nitrogenous Drinking WaterDisinfection By - Product. Environ. Sci. Technol. , 42 (3): 955 - 961. Richardson, S. D. Water Analysis: Emerging Contaminants andCurrent Issues. 2007. Anal. Chem ., 79(12): 4295 - 4324. Krasner, S. W., H. S. Weinberg, S. D. Richardson, S. Pastor, R. Chinn, M. J. Sclimenti, G. Onstad, and A. D. Thruston, Jr. 2006. The Occurrence of a New Generation of Disinfection Byproducts. Environ. Sci. Technol. , 40 (23): 7175 - 7185. Richardson. S. D. Environmental Mass Spectrometry: Emerging Contaminants and Current Issues. 2006. Anal. Chem ., 78 (12): 4021 - 4046. Richardson, S. D., and T. Ternes. 2005. WaterAnalysis: Emerging Contaminants and Current Issues. Anal. Chem ., 77 (12): 3807 - 3838. Cemeli, E., E. D. Wagner, D. Anderson, S. D. Richardson, and M. J. Plewa. 2006. Modulation of the Cytotoxicity and Genotoxicity of the Drinking Water DBP Iodoacetic Acid by Suppressors of Oxidative Stress. Environ. Sci. Technol ., 40 (6): 1878 - 1883. Vincenti, M., S. Biazzi, N. Ghiglione, M. C. Valsania, and S. D. Richardson. 2005. Comparison of Highly - Fluorinated Chloroformates as Direct Aqueous Sample Derivatizing Agents for Hydrophilic Analytes andDrinking Water Disinfection By - Products. J. Am. Soc. Mass Spectrom ., 16 (6): 803 - 813. Plewa, M. J., E. D. Wagner, S. D. Richardson, A. D. Thruston, Jr., Y. - T. Woo, and A. B. McKague. 2004. Chemical and Biological Characterization of Newly Discovered Iodoacid Drinking Water Disinfection Byproducts. Environ. Sci. Technol ., 38(18): 4713 - 4722. Zwiener, C., and S. D. Richardson. 2005. Drinking WaterDisinfection By - Product Analysis by LC/MS and LC/MS/MS. Trends Anal. Chem ., 24(7): 613 - 621. (Invited review article for special thematic issue on Liquid Chromatography - Tandem Mass Spectrometry). Plewa, M. J., E. D. Wagner, P. Jazwierska, S. D. Richardson, P. H. Chen, andA. B. McKague. 2004. Halonitromethane Drinking Water DisinfectionByproducts: Chemical Characterization and Mammalian Cell Cytotoxicity and Genotoxicity. Environ. Sci. Technol ., 38(1): 62 - 68. Kundu, B., S. D. Richardson, P. D. Swartz, P. P. Matthews, A. M. Richard, andD. M. DeMarini. 2004. Mutagenicity in Salmonella of

Halonitrometanes: A Recently Recognized Class of Disinfection By - Product inDrinking Water. Mutat. Res ., 562: 39 - 65. Kundu, B., S. D. Richardson, C. A. Granville, D. T. Shaughnessy, N. M. Hanley, P. D. Swartz, A. M. Richard, and D. M. DeMarini. 2004. Comparative Mutagenicity of Halomethanes and Halonitromethanes in SalmonellaTA100: Structure Activity Analysis and Mutation Spectra. Mutat. Res ., 554: 335 - 350. Richardson, S. D. 2004. Environmental Mass Spectrometry: Emerging Contaminants and Current Issues. Anal. Chem ., 76 (12): 3337 - 3364. Simmons, J. E., L. K. Teuschler, C. Gennings, T. F. Speth, S. D. Richardson, R. J. Miltner, M. G. Narotsky, K. D. Schenck, Page 5 of 7 Drinking Water | Ecosystems Research Division | US EPA

11/18/2010 file://C:\Program Files\Documentum\CTS\docbases\ProDocbase\config\temp_sessions\4902004198101473791\ ...E. S. Hunter, III, R. C. Hertzberg, III, and G. Rice. 2004. Component - Based and Whole - Mixture Techniques for Addressing the Toxicity of Drinking Water Disinfection Byproducts Mixtures. J. Toxicol. Environ. Health , 67: 741 - 754. Richardson, S.D., J. E. Simmons, and G. Rice. 2002. DBPs: The Next Generation. Environ. Sci. Technol ., 36 (9): 198A 205A. Woo, Y. - T., D. Lai, J. L. McLain, M. K. Manibusan, and V. Dellarco. 2002. Environ. Health Perspect ., 110 (Suppl. 1): 75 - 87. Richardson, S. D., A. D. Thruston, Jr., C. Rav - Acha, L. Groisman, I. Popilevsky, V. Glezer, A. B. McKague, M. J. Plewa, and E. D. Wagner. 2003. Tribromopyrrole and Other DBPs Produced by the Disinfection of Drinking Water Rich in Bromide. Environ. Sci. Technol ., 37(17): 3782 - 3793. Richardson, S. D. 2003. Water Analysis: Emerging Contaminants and Current Issues. Anal. Chem ., 75(12): 2831 - 2857. Richardson, S. D. 2003. Disinfection By - Products and OtherEmerging Contaminants in Drinking Water. Trends Anal. Chem ., 22(10):666 - 684. Weinberg, H. S., S. W. Krasner, S. D. Richardson, and A. D. Thruston, Jr. The Occurrence of Disinfection By - Products (DBPs) of Health Concern inDrinking Water: Results of a Nationwide DBP Occurrence Study. EPA/600/R02/068 . U.S. Environmental Protection Agency, National Exposure Research Laboratory, Athens, GA. 2002. Chen, P. H., S. D. Richardson, S. W. Krasner, G. Majetich, and G. L. Glish. 2002. Hydrogen Abstraction and Decomposition of

Tribromonitromethane and Other Trihalo Compounds by GC/MS. Environ. Sci. Technol ., 36(15): 3362 - 3371. Simmons, J. E., S. D. Richardson, T. F. Speth, R. J. Miltner, G. Rice, K. M. Schenck, E. S. Hunter, III, and L. K. Teuschler. 2002. Developmentof a Research Strategy for Integrated Technology - Based Toxicological and Chemical Evaluation of Complex Mixtures of Drinking Water DisinfectionByproducts. Environ. Health Perspect. , 110(Supp. 6): 1013 - 1024. Arbuckle, T. E., S. E. Hrudey, S. W. Krasner, J. R. Nuckols, S. D. Richardson, P. Singer, P. Mendola, L. Dodds, C. Weisel, D. L. Ashley, K. L. Froese, R. A. Pegram, I. R. Schultz, J. Reif, A. M. Bachand, F. M. Benoit, M. Lynberg, C. Poole, and K. Waller. 2002. Assessing Exposure inEpidemiologic Studies to Disinfection By - products in Drinking Water: Report froman International Workshop. Environ. Health Perspect ., 110 (Supp. 1): 53 - 60. Richardson, S. D., T. V. Caughran, T. Poiger, Y. Guo, and F. G. Crumley. 2000. Application of DNPH Derivatization with LC/MS to the Identification of Polar Carbonyl Disinfection By - products in Drinking Water. Ozone Sci. Engin ., 22: 653 - 675. Richardson, S. D., A. D. Thruston, Jr., T. V. Caughran, P. H. Chen, T. W. Collette, T. L. Floyd, K. M. Schenck, B. W. Lykins, Jr., G. - R. Sun, and G. Majetich. 1999. Identification of New Ozone Disinfection By - products in Drinking Water. Environ. Sci. Technol ., 33: 3368 - 3377. Richardson, S. D., A. D. Thruston, Jr., T. V. Caughran, P. H. Chen, T. W. Collette, T. L. Floyd, K. M. Schenck, B. W. Lykins, Jr., G. - R. Sun, and G. Majetich. 1999. Identification of New Drinking Water DisinfectionBy - products Formed in the Presence of Bromide. Environ. Sci. Technol ., 33: 3378 - 3383. Richardson, S. D., A. D. Thruston, Jr., T. V. Caughran, P. H. Chen, T. W. Collette, K. M. Schenck, B. W. Lykins, Jr., C. Rav - Acha, and V. Glezer. 2000. Identification of New Drinking Water DisinfectionBy - products from Ozone, Chlorine Dioxide, Chloramine, and Chlorine. Water Air Soil Pollut ., 123: 95 - 102. Page 6 of 7 Drinking Water | Ecosystems Research Division | US EPA

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