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Journal of Environmental Sciences 2022年第7期34卷 6-9页

作者： susan d.richardson department of Chemistry and Biochemistry University of South CarolinaColumbiaSC 29208USA

It is interesting how a random encounter can profoundly change your life. My random encounter was with a young graduate student from Michael Plewa’s laboratory. The location was the 1999 American Chemical Society (ACS) Conference, where, following his talk, this promising researcher was being unfairly criticized by a well-established scientist. I disagreed with this scientist’s criticism, and I encouraged the student how I thought his work was important.

关键词： breaking integrating analytical

do dBPs swim in salt water pools? Comparison of 60 dBPs formed by electrochemically generated chlorine vs. conventional chlorine

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Journal of Environmental Sciences 2022年第7期34卷 232-241页

作者： Caroline O.Granger susan d.richardson department of Chemistry and Biochemistry University of South Carolina631 Sumter St.ColumbiaSC 29208USA

disinfectants are added to swimming pools to kill harmful pathogens. Although liquid chlorine(sodium hypochlorite) is the most commonly used disinfectant, alternative disinfection techniques like electrochemically generated mixed oxidants or electrochemically generated chlorine, often referred to as salt water pools, are growing in popularity. However, these disinfectants react with natural organic matter and anthropogenic contaminants introduced to the pool water by swimmers to form disinfection byproducts(dBPs). dBPs have been linked to several adverse health effects, such as bladder cancer, adverse birth outcomes, and asthma. In this study, we quantified 60 dBPs using gas chromatography-mass spectrometry and assessed the calculated cytotoxicity and genotoxicity of an indoor community swimming pool before and after switching to a salt water pool with electrochemically generated chlorine. Interestingly, the total dBPs increased by 15% upon implementation of the salt water pool, but the calculated cytotoxicity and genotoxicity decreased by 45% and 15%, respectively. Predominant dBP classes formed were haloacetic acids, with trichloroacetic acid and dichloroacetic acid contributing 57% of the average total dBPs formed. Haloacetonitriles, haloacetic acids, and haloacetaldehydes were the primary drivers of calculated cytotoxicity, and haloacetic acids were the primary driver of calculated genotoxicity. diiodoacetic acid, a highly toxic iodinated dBP, is reported for the first time in swimming pool water. Bromide impurities in sodium chloride used to electrochemically generate chlorine led to a 73% increase in brominated dBPs, primarily driven by bromochloroacetic acid. This study presents the most extensive dBP study to-date for salt water pools.

关键词： disinfection byproducts Swimming pools Cytotoxicity Genotoxicity GC-MS

How well does XAd resin extraction recover halogenated disinfection byproducts for comprehensive identification and toxicity testing?

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Journal of Environmental Sciences 2022年第7期34卷 264-275页

作者： Xiaobin Liao Joshua M.Allen Caroline O.Granger susan d.richardson department of Chemistry and Biochemistry University of South CarolinaColumbiaSouth Carolina 29208USA Institute of Municipal and Environmental Engineering College of Civil EngineeringHuaqiao UniversityFujian 361021China Currently at LanzaTech 535 Commerce DriveSopertonGeorgia 30457USA

Halogenated disinfection byproducts(dBPs) are an unintended consequence of drinking water disinfection, and can have significant toxicity. XAd resins are commonly used to extract and enrich trace levels of dBPs for comprehensive, nontarget identification of dBPs and also for in vitro toxicity studies. However, XAd resin recoveries for complete classes of halogenated dBPs have not been evaluated, particularly for low, environmentally relevant levels(ng/L to low μg/L). Thus, it is not known whether levels of dBPs or the toxicity of drinking water might be underestimated. In this study, dAX-8/XAd-2 layered resins were evaluated, considering both adsorption and elution from the resins, for extracting 66 dBPs from water. Results demonstrate that among the 7 classes of dBPs investigated, trihalomethanes(THMs), including iodo-THMs, were the most efficiently adsorbed, with recovery of most THMs ranging from 50%-96%, followed by halonitromethanes(40%-90%). The adsorption ability of XAd resins for haloacetonitriles, haloacetamides, and haloacetaldehydes was highly dependent on the individual species. The adsorption capacity of XAd resins for haloacetic acids was lower(5%-48%), even after adjusting to p H 1 before extraction. Recovery efficiency for most dBPs was comparable with their adsorption, as most were eluted effectively from XAd resins by ethyl acetate. dBP polarity and molecular weight were the two most important factors that determine their recovery. Recovery of trichloromethane, iodoacetic acid, chloro-and iodo-acetonitrile, and chloroacetamide were among the lowest, which could lead to underestimation of toxicity, particularly for iodoacetic acid and iodo-acetonitrile, which are highly toxic.

关键词： XAd resins disinfection byproducts dBPs Recovery Toxicity

A balancing act: Optimizing free chlorine contact time to minimize iodo-dBPs, NdMA, and regulated dBPs in chloraminated drinking water

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Journal of Environmental Sciences 2022年第7期34卷 315-325页

作者： Matthew A.Bloodgood Sridevi Anduri Chowdary Eric J.daiber Honglan Shi Caroline O.Granger susan d.richardson Student Services Authority U.S.Environmental Protection AgencyNational Exposure Research LaboratoryAthensGA 30605USA department of Chemistry Missouri University of Science and TechnologyRollaMO 65409USA department of Chemistry and Biochemistry University of South CarolinaColumbiaSC 29208USA

Many drinking water treatment plants in the U.S. have switched from chlorination to chloramination to lower levels of regulated trihalomethane(THM) and haloacetic acid(HAA) disinfection byproducts(dBPs) in drinking water and meet the current regulations. However, chloramination can also produce other highly toxic/carcinogenic, unregulated dBPs: iodoacids, iodo-THMs, and N-nitrosodimethylamine(NdMA). In practice, chloramines are generated by the addition of chlorine with ammonia, and plants use varying amounts of free chlorine contact time prior to ammonia addition to effectively kill pathogens and meet dBP regulations. However, iodo-dBPs and nitrosamines are generally not considered in this balancing of free chlorine contact time. The goal of our work was to determine whether an optimal free chlorine contact time could be established in which iodo-dBPs and NdMA could be minimized, while keeping regulated THMs and HAAs below their regulatory limits. The effect of free chlorine contact time was evaluated for the formation of six iodo-trihalomethanes(iodo-THMs), six iodo-acids, and NdMA during the chloramination of drinking water. Ten different free chlorine contact times were examined for two source waters with different dissolved organic carbon(dOC) and bromide/iodide. For the low dOC water at pH 7 and 8, an optimized free chlorine contact time of up to 1 h could control regulated THMs and HAAs, as well as iodo-dBPs and NdMA. For the high dOC water, a free chlorine contact time of 5 min could control iodo-dBPs and NdMA at both p Hs, but the regulated dBPs could exceed the regulations at pH 7.

关键词： Iodo-dBPs NdMA disinfection byproducts Chloramine drinking water Free chlorine contact time

disinfection byproducts in chlorinated or brominated swimming pools and spas: Role of brominated dBPs and association with mutagenicity

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Journal of Environmental Sciences 2022年第7期34卷 253-263页

作者： Hannah K.Liberatore Eric J.daiber Sridevi A.Ravuri Judith E.Schmid susan d.richardson david M.deMarini Air Methods and Characterization division Center for Environmental Measurement and ModelingU.S.Environmental Protection AgencyResearch Triangle ParkNC 27711USA Student Services Authority U.S.Environmental Protection AgencyNational Exposure Research LaboratoryAthensGA 30605USA National Health and Environmental Effects Research Laboratory U.S.Environmental Protection AgencyResearch Triangle ParkNC 27711USA department of Chemistry and Biochemistry University of South CarolinaColumbiaSC 29208USA

Although the health benefits of swimming are well-documented, health effects such as asthma and bladder cancer are linked to disinfection by-products(dBPs) in pool water. dBPs are formed from the reaction of disinfectants such as chlorine(Cl) or bromine(Br) with organics in the water. Our previous study(daiber et al., Environ. Sci. Technol. 50, 6652;2016) found correlations between the concentrations of classes of dBPs and the mutagenic potencies of waters from chlorinated or brominated swimming pools and spas. We extended this study by identifying significantly different concentrations of 21 individual dBPs in brominated or chlorinated pool and spa waters as well as identifying which dBPs and additional dBP classes were most associated with the mutagenicity of these waters. Using data from our previous study, we found that among 21 dBPs analyzed in 21 pool and spa waters, the concentration of bromoacetic acid was significantly higher in Brwaters versus Cl-waters, whereas the concentration of trichloroacetic acid was significantly higher in Cl-waters. Five Br-dBPs(tribromomethane, dibromochloroacetic acid, dibromoacetonitrile, bromoacetic acid, and tribromoacetic acid) had significantly higher concentrations in Br-spa versus Cl-spa waters. Cl-pools had significantly higher concentrations of CldBPs(trichloroacetaldehyde, trichloromethane, dichloroacetic acid, and chloroacetic acid), whereas Br-pools had significantly higher concentrations of Br-dBPs(tribromomethane, dibromoacetic acid, dibromoacetonitrile, and tribromoacetic acid). The concentrations of the sum of all 4 trihalomethanes, all 11 Br-dBPs, and all 5 nitrogen-containing dBPs were each significantly higher in brominated than in chlorinated pools and spas. The 8 Br-dBPs were the only dBPs whose individual concentrations were significantly correlated with the mutagenic potencies of the pool and spa waters. These results, along with those from our earlier study, highlight the importance of Br-dBPs in the muta

关键词： Swimming pools Hot tubs Mutagenicity disinfection byproducts Spas

Relationships between regulated dBPs and emerging dBPs of health concern in U.S. drinking water

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Journal of Environmental Sciences 2022年第7期34卷 161-172页

作者： Stuart W.Krasner Ai Jia Chih-Fen T.Lee Raha Shirkhani Joshua M.Allen susan d.richardson Michael J.Plewa Metropolitan Water district of Southern California Water Quality LaboratoryCA 91750USA department of Chemistry and Biochemistry University of South CarolinaSC 29208USA department of Crop Sciences University of Illinois at Urbana-ChampaignIL 61801USA Safe Global Water Institute University of Illinois at Urbana-ChampaignIL 61801USA

A survey was conducted at eight U.S. drinking water plants, that spanned a wide range of water qualities and treatment/disinfection practices. Plants that treated heavily-wastewaterimpacted source waters had lower trihalomethane to dihaloacetonitrile ratios due to the presence of more organic nitrogen and HAN precursors. As the bromide to total organic carbon ratio increased, there was more bromine incorporation into dBPs. This has been shown in other studies for THMs and selected emerging dBPs(HANs), whereas this study examined bromine incorporation for a wider group of emerging dBPs(haloacetaldehydes, halonitromethanes). Moreover, bromine incorporation into the emerging dBPs was, in general, similar to that of the THMs. Epidemiology studies that show an association between adverse health effects and brominated THMs may be due to the formation of brominated emerging dBPs of heath concern. Plants with higher free chlorine contact times before ammonia addition to form chloramines had less iodinated dBP formation in chloraminated distribution systems, where there was more oxidation of the iodide to iodate(a sink for the iodide) by the chlorine. This has been shown in many bench-scale studies(primarily for iodinated THMs), but seldom in full-scale studies(where this study also showed the impact on total organic iodine. Collectively, the THMs, haloacetic acids, and emerging dBPs accounted for a significant portion of the TOCl, TOBr, and TOI;however, ~50% of the TOCl and TOBr is still unknown. The correlation of the sum of detected dBPs with the TOCl and TOBr suggests that they can be used as reliable surrogates.

关键词： disinfection by-products Total organic bromine Total organic iodine Trihalomethanes Haloacetonitriles Haloacetaldehydes Iodo-trihalomethanes Iodoacetic acids

A new technique helps to uncover unknown peptides and disinfection by-products in water

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Journal of Environmental Sciences 2016年第4期28卷 6-8页

作者： susan d.richardson Cristina Postigo department of Chemistry and Biochemistry University of South Carolina department of Environmental Chemistry Institute for Environmental Assessment and Water Research-Spanish National Research Council(IDAEA-CSIC)

Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter（NOM）and thousands that derive from anthropogenic *** complex as these samples are,drinking water can be even more *** to disinfectants that are used to treat drinking water（e.g.,chlorine,chloramines,

关键词： disinfection by-products(dBPs) drinking water Halogenated peptides Liquid chromatography Natural organic matter(NOM) Non-targeted analysis Tandem mass spectrometry Water contaminants

Formation of iodo-trihalomethanes, iodo-haloacetic acids, and haloacetaldehydes during chlorination and chloramination of iodine containing waters in laboratory controlled reactions

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Journal of Environmental Sciences 2017年第8期29卷 127-134页

作者： Cristina Postigo susan d.richardson damia Barceló Water and Soil Quality Research Group Department of Environmental Chemistry Institute of Environmental Assessment and Water Research (IDAEA-CSIC) Barcelona Spain department of Chemistry and Biochemistry University of South Carolina SC 29208 United States Catalan Institute for Water Research(ICRA) Parc Científic i Tecnològic de la Universitat de Girona17003 GironaSpain

Iodine containing disinfection by-products（I-dBPs） and haloacetaldehydes（HALs） are emerging disinfection by-product（dBP） classes of concern. The former due to its increased potential toxicity and the latter because it was found to be the third most relevant dBP class in mass in a U.S. nationwide drinking water study. These dBP classes have been scarcely investigated, and this work was performed to further explore their formation in drinking water under chlorination and chloramination scenarios. In order to do this, iodo-trihalomethanes（I-THMs）,iodo-haloacetic acids（I-HAAs） and selected HALs（mono-HALs and di-HALs species, including iodoacetaldehyde） were investigated in dBP mixtures generated after chlorination and chloramination of different water matrices containing different levels of bromide and iodide in laboratory controlled reactions. Results confirmed the enhancement of I-dBP formation in the presence of monochloramine. While I-THMs and I-HAAs contributed almost equally to total I-dBP concentrations in chlorinated water, I-THMs contributed the most to total I-dBP levels in the case of chloraminated water. The most abundant and common I-THM species generated were bromochloroiodomethane, dichloroiodomethane, and chlorodiiodomethane. Iodoacetic acid and chloroiodoacetic acid contributed the most to the total I-HAA concentrations measured in the investigated disinfected water. As for the studied HALs, dihalogenated species were the compounds that predominantly formed under both investigated treatments.

关键词： Iodinated disinfection by-products Chlorination Chloramination drinking water Mass spectrometry Iodo-trihalomethanes Iodo-haloacetic acids Haloacetaldehydes

TIC-Tox: A preliminary discussion on identifying the forcing agents of dBP-mediated toxicity of disinfected water

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Journal of Environmental Sciences 2017年第8期29卷 208-216页

作者： Michael J.Plewa Elizabeth d.Wagner susan d.richardson Safe Global Water Institute and the Department of Crop Sciences University of Illinois at Urbana-Champaign department of Chemistry and Biochemistry University of South Carolina

The disinfection of drinking water is a major public health achievement; however, an unintended consequence of disinfection is the generation of disinfection by-products（dBPs）. Many of the identified dBPs exhibit in vitro and in vivo toxicity, generate a diversity of adverse biological effects, and may be hazards to the public health and the *** a few dBPs are regulated by several national and international agencies and it is not clear if these regulated dBPs are the forcing agents that drive the observed toxicity and their associated health effects. In this study, we combine analytical chemical and biological data to resolve the forcing agents associated with mammalian cell cytotoxicity of drinking water samples from three cities. These data suggest that the trihalomethanes（THMs） and haloacetic acids may be a small component of the overall cytotoxicity of the organic material isolated from disinfected drinking water. Chemical classes of nitrogen-containing dBPs, such as the haloacetonitriles and haloacetamides, appear to be the major forcing agents of toxicity in these samples. These findings may have important implications for the design of epidemiological studies that primarily rely on the levels of THMs to define dBP exposure among populations. The TIC-Tox approach constitutes a beginning step in the process of identifying the forcing agents of toxicity in disinfected water.

关键词： dBPs CHO cell cytotoxicity Toxicity Additivity

Total organic halogen(TOX) in human urine: A halogen-specific method for human exposure studies

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Journal of Environmental Sciences 2017年第8期29卷 285-295页

作者： susana Y.Kimura Weiwei Zheng Taylor N.Hipp Joshua M.Allen susan d.richardson department of Chemistry and Biochemistry University of South Carolina Key Laboratory of Public Health Safety Ministry of Education Department of Environmental Health School of Public Health Fudan University

disinfection by-products（dBPs） are a complex mixture of compounds unintentionally formed as a result of disinfection processes used to treat drinking water. Effects of long-term exposure to dBPs are mostly unknown and were the subject of recent epidemiological studies. However,most bioanalytical methods focus on a select few dBPs. In this study, a new comprehensive bioanalytical method has been developed that can quantify mixtures of organic halogenated compounds, including dBPs, in human urine as total organic chlorine（TOCl）, total organic bromine（TOBr）, and total organic iodine（TOI）. The optimized method consists of urine dilution, adsorption to activated carbon, pyrolysis of activated carbon, absorption of gases in an aqueous solution, and halide analysis with ion chromatography and inductively coupled plasma-mass spectrometry. Spike recoveries for TOCl, TOBr, and TOI measurements ranged between 78% and 99%. Average TOCl, TOBr, and TOI concentrations in five urine samples from volunteers who consumed tap water were 1850, 82, and 21.0 μg/L as X^-, *** who consumed spring water（control） had TOCl, TOBr, and TOI average concentrations in urine of 1090, 88, and 10.3 μg/L as X^-, respectively. TOCl and TOI in the urine samples from tap water consumers were higher than the control. However, TOBr was slightly lower in tap water urine samples compared to mineral water urine samples, indicating other sources of environmental exposure other than drinking water. A larger sample population that consumes tap water from different cities and mineral water is needed to determine TOCl, TOBr, and TOI exposure from drinking water.

关键词： Adsorbable organic halogen(AOX) Total organic halogen(TOX) disinfection by-products(dBPs) Total organic chlorine(TOCl) Total organic bromine(TOBr) Total organic iodine(TOI) Urine drinking water