Susan D Richardson

University of South Carolina, Columbia, South Carolina, United States

Are you Susan D Richardson?

Claim your profile

Publications (78)317.13 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The introduction of drinking water disinfection greatly reduced waterborne diseases. However, the reaction between disinfectants and natural organic matter in the source water leads to an unintended consequence, the formation of drinking water disinfection byproducts (DBPs). The haloacetaldehydes (HALs) are the third largest group by weight of identified DBPs in drinking water. The primary objective of this study was to analyze the occurrence and comparative toxicity of the emerging HAL DBPs. A new HAL DBP, iodoacetaldehyde (IAL) was identified. This study provided the first systematic, quantitative comparison of HAL toxicity in Chinese hamster ovary cells. The rank order of HAL cytotoxicity is tribromoacetaldehyde (TBAL) ≈ chloroacetaldehyde (CAL) > dibromoacetaldehyde (DBAL) ≈ bromochloroacetaldehyde (BCAL) ≈ dibromochloroacetaldehyde (DBCAL) > IAL > bromoacetaldehyde (BAL) ≈ bromodichloroacetaldehyde (BDCAL) > dichloroacetaldehyde (DCAL) > trichloroacetaldehyde (TCAL). The HALs were highly cytotoxic compared to other DBP chemical classes. The rank order of HAL genotoxicity is DBAL > CAL ≈ DBCAL > TBAL ≈ BAL > BDCAL > BCAL ≈ DCAL > IAL. TCAL was not genotoxic. Because of their toxicity and abundance, further research is needed to investigate their mode of action to protect the public health and the environment.
    Environmental Science & Technology 05/2015; DOI:10.1021/es506358x
  • [Show abstract] [Hide abstract]
    ABSTRACT: The transformation of the iodinated X-ray contrast media (ICM) iopamidol, iopromide, iohexol, iomeprol, and diatrizoate was examined in purified water over the pH range from 6.5 to 8.5 in the presence of sodium hypochlorite, monochloramine, and chlorine dioxide. In the presence of aqueous chlorine, only iopamidol was transformed. All other ICM did not show significant reactivity, regardless of the oxidant used. Chlorination of iopamidol followed a second order reaction, with an observed rate constant of up to 0.87 M(-1) s(-1) (±0.021 M(-1) s(-1)) at pH 8.5. The hypochlorite anion was identified to be the reactive chlorine species. Iodine was released during the transformation of iopamidol, and was mainly oxidized to iodate. Only a small percentage (less than 2% after 24 h) was transformed to known organic iodinated disinfection byproducts (DBPs) of low molecular weight. Some of the iodine was still present in high-molecular weight DBPs. The chemical structures of these DBPs were elucidated via MS(n) fragmentation and NMR. Side chain cleavage was observed as well as the exchange of iodine by chlorine. An overall transformation pathway was proposed for the degradation of iopamidol. CHO cell chronic cytotoxicity tests indicate that chlorination of iopamidol generates a toxic mixture of high molecular weight DBPs (LC50 332 ng/μL).
    Environmental Science and Technology 10/2014; 48(21). DOI:10.1021/es503609s
  • [Show abstract] [Hide abstract]
    ABSTRACT: The changes in dissolved organic matter (DOM) throughout the treatment processes in a drinking water treatment plant in Sweden and the formation of disinfection by-products (DBPs) were evaluated by using ultrahigh resolution mass spectrometry (resolution ~ 500,000 at m/z 400) and nuclear magnetic resonance (NMR). Mass spectrometric results revealed that flocculation induced substantial changes in the DOM and caused quantitative removal of DOM constituents that usually are associated with DBP formation. While half of the chromophoric DOM (CDOM) was removed by flocculation, about 4-5 mg L-1 total organic carbon remained in the finished water. A conservative approach revealed the formation of about 800 mass spectrometry ions with unambiguous molecular formula assignments that contained at least one halogen atom. These molecules likely represented new DBPs, which could not be prevented by the flocculation process. The most abundant m/z peaks, associated with formed DBPs, could be assigned to C5HO3Cl3, C5HO3Cl2Br and C5HO3ClBr2 by using isotope simulation patterns with the likely DBPs were produced and suggested the presence of halogenated polyphenolic and aromatic acid-type structures, which was supported by possible structures that matched the lower molecular mass range (max. 10 carbon atoms) of these DBPs. 1H-NMR before and after disinfection revealed about a 2% change of the overall 1H-NMR signals supporting a significant change of the DOM caused by disinfection. This study underlines that a large and increasing number of people are exposed to a very diverse pool of organohalogens through water - by both drinking and uptake through the skin upon contact. Non-target analytical approaches are indispensable to reveal the magnitude of this exposure and to test alternative ways to reduce it.
    Environmental Science and Technology 10/2014; 48(21). DOI:10.1021/es504349p
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Uptake and discharge of ballast water by ocean-going ships contribute to the worldwide spread of aquatic invasive species, with negative impacts on the environment, economies, and public health. The International Ballast Water Management Convention aims at a global answer. The agreed standards for ballast water discharge will require ballast water treatment. Systems based on various physical and/or chemical methods were developed for on-board installation and approved by the International Maritime Organization. Most common are combinations of high-performance filters with oxidizing chemicals or UV radiation. A well-known problem of oxidative water treatment is the formation of disinfection by-products, many of which show genotoxicity, carcinogenicity, or other long-term toxicity. In natural biota, genetic damages can affect reproductive success and ultimately impact biodiversity. The future exposure towards chemicals from ballast water treatment can only be estimated, based on land-based testing of treatment systems, mathematical models, and exposure scenarios. Systematic studies on the chemistry of oxidants in seawater are lacking, as are data about the background levels of disinfection by-products in the oceans and strategies for monitoring future developments. The international approval procedure of ballast water treatment systems compares the estimated exposure levels of individual substances with their experimental toxicity. While well established in many substance regulations, this approach is also criticised for its simplification, which may disregard critical aspects such as multiple exposures and long-term sub-lethal effects. Moreover, a truly holistic sustainability assessment would need to take into account factors beyond chemical hazards, e.g. energy consumption, air pollution or waste generation.
    Chemosphere 10/2014; 112:256–266. DOI:10.1016/j.chemosphere.2014.03.135
  • 248th American Chemical Society National Meeting and Exposition, San Francisco, CA; 08/2014
  • o 248th American Chemical Society National Meeting and Exposition, San Francisco, CA; 08/2014
  • Cristina Postigo, Susan D Richardson
    [Show abstract] [Hide abstract]
    ABSTRACT: Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment.
    Journal of Hazardous Materials 07/2014; 279C:461-475. DOI:10.1016/j.jhazmat.2014.07.029
  • Xing-Fang Li, Susan D Richardson
    Journal of the American Society for Mass Spectrometry 05/2014; 25(7). DOI:10.1007/s13361-014-0876-1
  • 245th American Chemical Society National Meeting and Exposition, New Orleans, LA; 04/2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: The HIWATE (Health Impacts of long-term exposure to disinfection byproducts in drinking WATEr) project was a systematic analysis that combined the epidemiology on adverse pregnancy outcomes and other health effects with long-term exposure to low levels of drinking water disinfection byproducts (DBPs) in the European Union. The present study focused on the relationship of the occurrence and concentration of DBPs with in vitro mammalian cell toxicity. Eleven drinking water samples were collected from five European countries. Each sampling location corresponded with an epidemiological study for the HIWATE program. Over 90 DBPs were identified; the range in the number of DBPs and their levels reflected the diverse collection sites, different disinfection processes, and the different characteristics of the source waters. For each sampling site, chronic mammalian cell cytotoxicity correlated highly with the numbers of DBPs identified and the levels of DBP chemical classes. Although there was a clear difference in the genotoxic responses among the drinking waters, these data did not correlate as well with the chemical analyses. Thus, the agents responsible for the genomic DNA damage observed in the HIWATE samples may be due to unresolved associations of combinations of identified DBPs, unknown emerging DBPs that were not identified, or other toxic water contaminants. This study represents the first to integrate quantitative in vitro toxicological data with analytical chemistry and human epidemiologic outcomes for drinking water DBPs.
    Environmental Science & Technology 09/2012; 46(21). DOI:10.1021/es3024226
  • [Show abstract] [Hide abstract]
    ABSTRACT: A developmental toxicity bioassay was used in three experiments to evaluate water concentrates for suitability in multigenerational studies. First, chlorinated water was concentrated 135-fold by reverse osmosis; select lost disinfection by-products were spiked back. Concentrate was provided as drinking water to Sprague-Dawley and F344 rats from gestation day 6 to postnatal day 6. Maternal serum levels of luteinizing hormone on gestation day 10 were unaffected by treatment for both strains. Treated dams had increased water consumption, and increased incidences of polyuria, diarrhea, and (in Sprague-Dawley rats) red perinasal staining. Pup weights were reduced. An increased incidence of eye defects was seen in F344 litters. Chemical analysis of the concentrate revealed high sodium (6.6 g/l) and sulfate (10.4 g/l) levels. To confirm that these chemicals caused polyuria and osmotic diarrhea, respectively, Na₂SO₄ (5-20 g/l) or NaCl (16.5 g/l) was provided to rats in drinking water. Water consumption was increased at 5- and 10-g Na₂SO₄/l and with NaCl. Pup weights were reduced at 20-g Na₂SO₄/l. Dose-related incidences and severity of polyuria and diarrhea occurred in Na₂SO₄-treated rats; perinasal staining was seen at 20 g/l. NaCl caused polyuria and perinasal staining, but not diarrhea. Subsequently, water was concentrated ∼120-fold and sulfate levels were reduced by barium hydroxide before chlorination, yielding lower sodium (≤1.5 g/l) and sulfate (≤2.1 g/l) levels. Treatment resulted in increased water consumption, but pup weight and survival were unaffected. There were no treatment-related clinical findings, indicating that mixtures produced by the second method are suitable for multigenerational testing.
    Birth Defects Research Part B Developmental and Reproductive Toxicology 06/2012; 95(3):202-12. DOI:10.1002/bdrb.21004
  • [Show abstract] [Hide abstract]
    ABSTRACT: The reaction between ozone and the three cresol isomers was investigated in pure water. Cresols were selected as model substrates representing an important component of humic material. Cresols carry both a hydroxyl and a methyl group, each theoretically increasing the reactivity of ozone with the aromatic ring. Direct comparison of the aromatic ring and the methyl group reactivities was made possible by the analysis of reaction products. The substrate degradation kinetics was studied by preparing aqueous solutions of each cresol and treating them with ozone for increasing time periods. It had been hypothesized that hydroxybenzaldehydes and hydroxybenzoic acids could be possible degradation intermediates of cresols. To verify this hypothesis, the degradation kinetics of three hydroxybenzaldehydes and two hydroxybenzoic acids were also studied. The reaction products were studied using gas chromatography (GC)-electron capture negative ionization (ECNI)-mass spectrometry (MS) analysis after direct derivatization of the samples with 5-chloro-2,2,3,3,4,4,5,5-octafluoro-1-pentyl chloroformate (ClOFPCF). This new analytical approach enables the extraction and analysis of highly polar polycarboxylic and hydroxycarboxylic acids, as well as highly polar aldehydes and hydroxy aldehydes that are difficult to extract and measure using conventional methods. As such, this new approach offered insights into ozone reaction intermediates that had been previously hypothesized, but not confirmed. Several highly hydrophilic degradation intermediates were identified, including malic, citraconic, itaconic, malonic, methylmuconic, and tartronic acid, but no hydroxybenzaldehydes were observed. The results support a 3-stage mechanism previously hypothesized, which involves ring-opening of the phenolic group, followed by the generation of several intermediates of increasing oxidation state, finally leading to relatively stable products, such as malonic and oxalic acids. We demonstrated that oxidation of the methyl group does not occur during cresol degradation.
    Water Research 02/2012; 46(8):2795-804. DOI:10.1016/j.watres.2012.02.040
  • Source
    Susan D Richardson
    Analytical Chemistry 12/2011; 84(2):747-78. DOI:10.1021/ac202903d
  • [Show abstract] [Hide abstract]
    ABSTRACT: Iodinated X-ray contrast media (ICM) were investigated as a source of iodine in the formation of iodo-trihalomethane (iodo-THM) and iodo-acid disinfection byproducts (DBPs), both of which are highly genotoxic and/or cytotoxic in mammalian cells. ICM are widely used at medical centers to enable imaging of soft tissues (e.g., organs, veins, blood vessels) and are designed to be inert substances, with 95% eliminated in urine and feces unmetabolized within 24 h. ICM are not well removed in wastewater treatment plants, such that they have been found at elevated concentrations in rivers and streams (up to 100 μg/L). Naturally occurring iodide in source waters is believed to be a primary source of iodine in the formation of iodo-DBPs, but a previous 23-city iodo-DBP occurrence study also revealed appreciable levels of iodo-DBPs in some drinking waters that had very low or no detectable iodide in their source waters. When 10 of the original 23 cities' source waters were resampled, four ICM were found--iopamidol, iopromide, iohexol, and diatrizoate--with iopamidol most frequently detected, in 6 of the 10 plants sampled, with concentrations up to 2700 ng/L. Subsequent controlled laboratory reactions of iopamidol with aqueous chlorine and monochloramine in the absence of natural organic matter (NOM) produced only trace levels of iodo-DBPs; however, when reacted in real source waters (containing NOM), chlorine and monochloramine produced significant levels of iodo-THMs and iodo-acids, up to 212 nM for dichloroiodomethane and 3.0 nM for iodoacetic acid, respectively, for chlorination. The pH behavior was different for chlorine and monochloramine, such that iodo-DBP concentrations maximized at higher pH (8.5) for chlorine, but at lower pH (6.5) for monochloramine. Extracts from chloraminated source waters with and without iopamidol, as well as from chlorinated source waters with iopamidol, were the most cytotoxic samples in mammalian cells. Source waters with iopamidol but no disinfectant added were the least cytotoxic. While extracts from chlorinated and chloraminated source waters were genotoxic, the addition of iopamidol enhanced their genotoxicity. Therefore, while ICM are not toxic in themselves, their presence in source waters may be a source of concern because of the formation of highly toxic iodo-DBPs in chlorinated and chloraminated drinking water.
    Environmental Science & Technology 08/2011; 45(16):6845-54. DOI:10.1021/es200983f
  • Source
    Susan D Richardson, Thomas A Ternes
    [Show abstract] [Hide abstract]
    ABSTRACT: This biennial review covers developments in water analysis for emerging environmental contaminants over the period of 2011-2013. Analytical Chemistry's policy is to limit reviews to a maximum of 250 significant references and to mainly focus on new trends. As a result, only a small fraction of the quality research publications could be discussed. I am excited to again have Thomas Ternes join me this year to cover the section on Pharmaceuticals and Hormones. Thomas coauthored the previous 2011 Review on Water Analysis,1 and as before, this Review is so much better with his contribution. We welcome any comments you have on this Review (richardson.susan@sc.edu). Numerous abstracts were consulted before choosing the best representative ones to present here. Abstract searches were carried out using Web of Science, and in many cases, full articles were obtained. A table of acronyms is provided (Table 1) as a quick reference to the acronyms of analytical techniques and other terms discussed in this Review, and Table 2 provides some useful websites.
    Analytical Chemistry 06/2011; 83(12):4614-48. DOI:10.1021/ac200915r
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Swimming pool disinfectants and disinfection by-products (DBPs) have been linked to human health effects, including asthma and bladder cancer, but no studies have provided a comprehensive identification of DBPs in the water and related that to mutagenicity. We performed a comprehensive identification of DBPs and disinfectant species in waters from public swimming pools in Barcelona, Catalonia, Spain, that disinfect with either chlorine or bromine and we determined the mutagenicity of the waters to compare with the analytical results. We used gas chromatography/mass spectrometry (GC/MS) to measure trihalomethanes in water, GC with electron capture detection for air, low- and high-resolution GC/MS to comprehensively identify DBPs, photometry to measure disinfectant species (free chlorine, monochloroamine, dichloramine, and trichloramine) in the waters, and an ion chromatography method to measure trichloramine in air. We assessed mutagenicity with the Salmonella mutagenicity assay. We identified > 100 DBPs, including many nitrogen-containing DBPs that were likely formed from nitrogen-containing precursors from human inputs, such as urine, sweat, and skin cells. Many DBPs were new and have not been reported previously in either swimming pool or drinking waters. Bromoform levels were greater in brominated than in chlorinated pool waters, but we also identified many brominated DBPs in the chlorinated waters. The pool waters were mutagenic at levels similar to that of drinking water (approximately 1,200 revertants/L-equivalents in strain TA100-S9 mix). This study identified many new DBPs not identified previously in swimming pool or drinking water and found that swimming pool waters are as mutagenic as typical drinking waters.
    Environmental Health Perspectives 11/2010; 118(11):1523-30. DOI:10.1289/ehp.1001965
  • [Show abstract] [Hide abstract]
    ABSTRACT: The haloacetic acids (HAAs) are disinfection by-products (DBPs) that are formed during the disinfection of drinking water, wastewaters and recreational pool waters. Currently, five HAAs [bromoacetic acid (BAA), dibromoacetic acid (DBAA), chloroacetic acid (CAA), dichloroacetic acid (DCAA), and trichloroacetic acid (TCAA); designated as HAA5] are regulated by the U.S. EPA, at a maximum contaminant level of 60 μg/L for the sum of BAA, DBAA, CAA, DCAA, and TCAA. We present a comparative systematic analysis of chronic cytotoxicity and acute genomic DNA damaging capacity of 12 individual HAAs in mammalian cells. In addition to the HAA5, we analyzed iodoacetic acid (IAA), diiodoacetic acid (DiAA), bromoiodoacetic acid (BIAA), tribromoacetic acid (TBAA), chlorodibromoacetic acid (CDBAA), bromodichloroacetic acid (BDCAA), and bromochloroacetic acid (BCAA). Their rank order of chronic cytotoxicity in Chinese hamster ovary cells was IAA > BAA > TBAA > CDBAA > DIAA > DBAA > BDCAA > BCAA > CAA > BIAA > TCAA > DCAA. The rank order for genotoxicity was IAA > BAA > CAA > DBAA > DIAA > TBAA > BCAA > BIAA > CDBAA. DCAA, TCAA, and BDCAA were not genotoxic. The trend for both cytotoxicity and genotoxicity is iodinated HAAs > brominated HAAs > chlorinated HAAs. The use of alternative disinfectants other than chlorine generates new DBPs and alters their distribution. Systematic, comparative, in vitro toxicological data provides the water supply community with information to consider when employing alternatives to chlorine disinfection. In addition, these data aid in prioritizing DBPs and their related compounds for future in vivo toxicological studies and risk assessment.
    Environmental and Molecular Mutagenesis 10/2010; 51(8-9):871-8. DOI:10.1002/em.20585
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Due to their efficacy in deactivating a range of microbial pathogens, particularly amoebic cysts, iodine-based disinfectants have been a popular option for point-of-use (POU) drinking water disinfection by campers, the military, and rural consumers in developing countries. Recently, concerns regarding the formation of cytotoxic and genotoxic iodinated disinfection byproducts (I-DBPs) have arisen during chloramine disinfection of iodide-containing waters in the developed world; similar concerns should pertain to iodine-based POU disinfection. Because there are alternative POU disinfection techniques, including chlorine-based disinfectants, this paper compared disinfection byproduct formation from a range of iodine-based disinfectants at their recommended dosages to chlorination and chloramination under overdosing conditions. Just as chloroform was the predominant trihalomethane (THM) forme during chlorination or chloramination, iodoform was the predominant THM formed during iodination. Conditions fostering THM formation were similar between these treatments, except that THM formation during chlorination increased with pH, while it was slightly elevated at circumneutral pH during iodination. Iodoform formation during treatment with iodine tincture was higher than during treatment with iodine tablets. On a molar basis, iodoform formation during treatment with iodine tincture was 20-60% of the formation of chloroform during chlorination, and total organic iodine (TOI) formation was twice that of total organic chlorine (TOCl), despite the 6-fold higher oxidant dose during chlorination. Based upon previous measurements of chronic mammalian cell cytotoxicity for the individual THMs, consumers of two waters treated with iodine tincture would receive the same THM-associated cytotoxic exposure in 4-19 days as a consumer of the same waters treated with a 6-fold higher dose of chlorine over 1 year. Iodoacetic acid, diiodoacetic acid, and other iodo-acids were also formed with iodine tincture treatment, but at levels <11% of iodoform. However, testing of a Lifestraw Personal POU device, which combines an iodinated anion exchange resin with activated carbon post-treatment, indicated minimal formation of I-DBPs and no iodine residual. Although N-nitrosamines have been associated with oxidant contact with anion exchange resins, N-nitrosamine formation rapidly declined to low levels (4 ng/L) using the Lifestraw device after the first few flushes of water.
    Environmental Science & Technology 10/2010; 44(22):8446-52. DOI:10.1021/es102746u
  • Source
    Susan D Richardson
    Analytical Chemistry 06/2010; 82(12):4742-74. DOI:10.1021/ac101102d
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The U.S. Environmental Protection Agency's "Four Lab Study" involved participation of researchers from four national Laboratories and Centers of the Office of Research and Development along with collaborators from the water industry and academia. The study evaluated toxicological effects of complex disinfection byproduct (DBP) mixtures, with an emphasis on reproductive and developmental effects that have been associated with DBP exposures in some human epidemiologic studies. This paper describes a new procedure for producing chlorinated drinking water concentrate for animal toxicology experiments, comprehensive identification of >100 DBPs, and quantification of 75 priority and regulated DBPs. In the research reported herein, complex mixtures of DBPs were produced by concentrating a natural source water with reverse osmosis membranes, followed by addition of bromide and treatment with chlorine. By concentrating natural organic matter in the source water first and disinfecting with chlorine afterward, DBPs (including volatiles and semivolatiles) were formed and maintained in a water matrix suitable for animal studies. DBP levels in the chlorinated concentrate compared well to those from EPA's Information Collection Rule (ICR) and a nationwide study of priority unregulated DBPs when normalized by total organic carbon (TOC). DBPs were relatively stable over the course of the animal studies (125 days) with multiple chlorination events (every 5-14 days), and a significant portion of total organic halogen was accounted for through a comprehensive identification approach. DBPs quantified included regulated DBPs, priority unregulated DBPs, and additional DBPs targeted by the ICR. Many DBPs are reported for the first time, including previously undetected and unreported haloacids and haloamides. The new concentration procedure not only produced a concentrated drinking water suitable for animal experiments, but also provided a greater TOC concentration factor (136×), enhancing the detection of trace DBPs that are often below detection using conventional approaches.
    Environmental Science & Technology 05/2010; 44(19):7184-92. DOI:10.1021/es9039314

Publication Stats

5k Citations
317.13 Total Impact Points

Institutions

  • 2011–2014
    • University of South Carolina
      • Department of Chemistry and Biochemistry
      Columbia, South Carolina, United States
  • 1991–2012
    • The Ohio Environmental Protection Agency
      Columbus, Ohio, United States
  • 2007
    • University of North Carolina at Chapel Hill
      • Department of Environmental Sciences and Engineering
      North Carolina, United States
  • 2003–2007
    • University of Illinois, Urbana-Champaign
      • Department of Crop Sciences
      Urbana, IL, United States
  • 2005
    • Karlsruhe Institute of Technology
      • Engler Bunte Institute
      Karlsruhe, Baden-Wuerttemberg, Germany
  • 2002–2005
    • United States Environmental Protection Agency
      • • National Exposure Research Laboratory
      • • Office of Research and Development
      Cincinnati, Ohio, United States