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Dr. James McCord
Center for Environmental Measurement and Modeling, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA

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0 Exposure Assessment
0 Mass Spectrometry
0 PFAS
0 non-targeted analysis
0 Emerging organic pollutants

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Mass Spectrometry
PFAS
non-targeted analysis

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Rapid communication
Published: 17 May 2021 in Environmental Science & Technology Letters
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Of the thousands of per- and polyfluoroalkyl substances (PFAS) in the environment, few have been investigated in detail. In this study, we analyzed 36 legacy and emerging PFAS in multiple seabird tissues collected from individuals from Massachusetts Bay, Narragansett Bay, and the Cape Fear River Estuary. PFOS was the dominant compound across multiple tissues, while long-chain perfluorinated carboxylic acids (PFCAs) dominated in brain (mean = 44% of total concentrations). Emerging perfluoroalkyl ether acids (PFEAs)—Nafion byproduct-2 and PFO5DoDA—were detected in greater than 90% of tissues in birds obtained from a nesting region downstream from a major fluorochemical production site. Compound ratios, relative body burden calculations, and electrostatic surface potential calculations were used to describe partitioning behavior of PFEAs in different tissues. Novel PFEAs preferentially partition into blood compared to liver and were documented in brain for the first time. PFO5DoDA showed a reduced preference for brain compared to PFCAs and Nafion BP2. These results suggest future monitoring efforts and toxicological studies should focus on novel PFAS and long-chain PFCAs in multiple tissues beyond liver and blood, while exploring the unique binding mechanisms driving uptake of multi-ether PFEAs.

ACS Style

Anna R. Robuck; James P. McCord; Mark J. Strynar; Mark G. Cantwell; David N. Wiley; Rainer Lohmann. Tissue-Specific Distribution of Legacy and Novel Per- and Polyfluoroalkyl Substances in Juvenile Seabirds. Environmental Science & Technology Letters 2021, 8, 457 -462.

AMA Style

Anna R. Robuck, James P. McCord, Mark J. Strynar, Mark G. Cantwell, David N. Wiley, Rainer Lohmann. Tissue-Specific Distribution of Legacy and Novel Per- and Polyfluoroalkyl Substances in Juvenile Seabirds. Environmental Science & Technology Letters. 2021; 8 (6):457-462.

Chicago/Turabian Style

Anna R. Robuck; James P. McCord; Mark J. Strynar; Mark G. Cantwell; David N. Wiley; Rainer Lohmann. 2021. "Tissue-Specific Distribution of Legacy and Novel Per- and Polyfluoroalkyl Substances in Juvenile Seabirds." Environmental Science & Technology Letters 8, no. 6: 457-462.

Short communication
Published: 31 March 2021 in Science of The Total Environment
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On September 14, 2018, Hurricane Florence delivered ~686 mm rainfall to a 106 km2 watershed in coastal North Carolina, USA. A forested land treatment site comprises one third of the watershed wherein municipal wastewater effluent is spray-irrigated onto 8.9 km2 of forest. This communication provides insight for land treatment function under excess water duress as well as changes in organic chemical composition in on- and off-site waters before (June 2018) and after (September & December 2018) Hurricane Florence's landfall. We compare the numbers and relative abundances of chemical features detected using suspect screening high resolution mass spectrometry in waste-, ground-, and surface water samples. Values for upstream and receiving waters in September were lower than for sampling events in June and December, indicating an expected dilution effect across the watershed. Chemical diversity was greatest for all surface water samples in December, but only upstream surface water showed a dramatic five-fold increase in relative chemical abundance. Chemical abundance in on-site water and downstream surface water was equal to or lower than the September storm dilution effect. These data suggest that the land treatment system is functionally and hydrologically robust to extreme storm events and contributed to dilution of upstream chemical reservoirs for downstream receiving waters for months after the storm. Similar systems may embody one water reuse strategy robust to the increasing occurrence of extreme precipitation events.

ACS Style

Melanie L. Hedgespeth; James P. McCord; Katherine A. Phillips; Mark J. Strynar; Damian Shea; Elizabeth Guthrie Nichols. Suspect-screening analysis of a coastal watershed before and after Hurricane Florence using high-resolution mass spectrometry. Science of The Total Environment 2021, 782, 146862 .

AMA Style

Melanie L. Hedgespeth, James P. McCord, Katherine A. Phillips, Mark J. Strynar, Damian Shea, Elizabeth Guthrie Nichols. Suspect-screening analysis of a coastal watershed before and after Hurricane Florence using high-resolution mass spectrometry. Science of The Total Environment. 2021; 782 ():146862.

Chicago/Turabian Style

Melanie L. Hedgespeth; James P. McCord; Katherine A. Phillips; Mark J. Strynar; Damian Shea; Elizabeth Guthrie Nichols. 2021. "Suspect-screening analysis of a coastal watershed before and after Hurricane Florence using high-resolution mass spectrometry." Science of The Total Environment 782, no. : 146862.

Research article
Published: 11 November 2020 in Environmental Science & Technology
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Aqueous film-forming foams (AFFF) are mixtures formulated with numerous hydrocarbon- and fluoro-containing surfactants. AFFF use leads to environmental releases of unknown per- and polyfluoroalkyl substances (PFAS). AFFF composition is seldom disclosed, and their use elicits concerns from both regulatory agencies and the public because PFAS are persistent in the environment and potentially associated with adverse health effects. In this study, we demonstrate the use of coupled liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC-IMS-MS) to rapidly characterize both known and unknown PFAS in AFFF. Ten AFFF formulations from seven brands were analyzed using LC-IMS-MS in both negative and positive ion modes. Untargeted analysis of the formulations was followed by feature identification of PFAS-like features utilizing database matching, mass defect and homologous series evaluation, and MS/MS fragmentation experiments. Across the tested AFFF formulations, we identified 33 homologous series; only ten of these homologous series have been previously reported. Among tested AFFF, the FireStopper (n = 85) contained the greatest number of PFAS-like features and Phos-Check contained zero. This work demonstrates that LC-IMS-MS-enabled untargeted analysis of complex formulations, followed by feature identification using data-processing algorithms, can be used for rapid exposure characterization of known and putative PFAS during fire suppression-related contamination events.

ACS Style

Yu-Syuan Luo; Noor A. Aly; James Mccord; Mark J. Strynar; Weihsueh A. Chiu; James N. Dodds; Erin S. Baker; Ivan Rusyn. Rapid Characterization of Emerging Per- and Polyfluoroalkyl Substances in Aqueous Film-Forming Foams Using Ion Mobility Spectrometry–Mass Spectrometry. Environmental Science & Technology 2020, 54, 15024 -15034.

AMA Style

Yu-Syuan Luo, Noor A. Aly, James Mccord, Mark J. Strynar, Weihsueh A. Chiu, James N. Dodds, Erin S. Baker, Ivan Rusyn. Rapid Characterization of Emerging Per- and Polyfluoroalkyl Substances in Aqueous Film-Forming Foams Using Ion Mobility Spectrometry–Mass Spectrometry. Environmental Science & Technology. 2020; 54 (23):15024-15034.

Chicago/Turabian Style

Yu-Syuan Luo; Noor A. Aly; James Mccord; Mark J. Strynar; Weihsueh A. Chiu; James N. Dodds; Erin S. Baker; Ivan Rusyn. 2020. "Rapid Characterization of Emerging Per- and Polyfluoroalkyl Substances in Aqueous Film-Forming Foams Using Ion Mobility Spectrometry–Mass Spectrometry." Environmental Science & Technology 54, no. 23: 15024-15034.

Journal article
Published: 04 November 2020 in Environmental Science & Technology Letters
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Hundreds of public water systems across the United States have been contaminated by the use of aqueous film-forming foams (AFFF) containing per- and polyfluoroalkyl substances (PFAS) during firefighting and training activities. Prior work shows AFFF contain hundreds of polyfluoroalkyl precursors missed by standard methods. However, the most abundant precursors in AFFF remain uncertain, and mixture contents are confidential business information, hindering proactive management of PFAS exposure risks. Here, we develop and apply a novel method (Bayesian inference) for reconstructing the fluorinated chain lengths, manufacturing origin, and concentrations of oxidizable precursors obtained from the total oxidizable precursor (TOP) assay that is generally applicable to all aqueous samples. Results show virtually all (median 104 ± 19%) extractable organofluorine (EOF) in contemporary and legacy AFFF consists of targeted compounds and oxidizable precursors, 90% of which are 6:2 fluorotelomers in contemporary products. Using high-resolution mass spectrometry, we further resolved the 6:2 fluorotelomers to assign the identity of 14 major compounds, yielding a priority list that accounts for almost all detectable PFAS in contemporary AFFF. This combination of methods can accurately assign the total PFAS mass attributable to AFFF in any aqueous sample with differentiation of gross precursor classes and identification of major precursor species.

ACS Style

Bridger J. Ruyle; Colin P. Thackray; James P. McCord; Mark J. Strynar; Kevin A. Mauge-Lewis; Suzanne E. Fenton; Elsie M. Sunderland. Reconstructing the Composition of Per- and Polyfluoroalkyl Substances in Contemporary Aqueous Film-Forming Foams. Environmental Science & Technology Letters 2020, 8, 59 -65.

AMA Style

Bridger J. Ruyle, Colin P. Thackray, James P. McCord, Mark J. Strynar, Kevin A. Mauge-Lewis, Suzanne E. Fenton, Elsie M. Sunderland. Reconstructing the Composition of Per- and Polyfluoroalkyl Substances in Contemporary Aqueous Film-Forming Foams. Environmental Science & Technology Letters. 2020; 8 (1):59-65.

Chicago/Turabian Style

Bridger J. Ruyle; Colin P. Thackray; James P. McCord; Mark J. Strynar; Kevin A. Mauge-Lewis; Suzanne E. Fenton; Elsie M. Sunderland. 2020. "Reconstructing the Composition of Per- and Polyfluoroalkyl Substances in Contemporary Aqueous Film-Forming Foams." Environmental Science & Technology Letters 8, no. 1: 59-65.

Journal article
Published: 27 October 2020 in Environment International
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Hexafluoropropylene oxide dimer acid (HFPO-DA or GenX) is an industrial replacement for the straight-chain perfluoroalkyl substance (PFAS), perfluorooctanoic acid (PFOA). Previously we reported maternal, fetal, and postnatal effects from gestation day (GD) 14-18 oral dosing in Sprague-Dawley rats. Here, we further evaluated the perinatal toxicity of HFPO-DA by orally dosing rat dams with 1–125 mg/kg/d (n = 4 litters per dose) from GD16-20 and with 10–250 mg/kg/d (n = 5) from GD8 – postnatal day (PND) 2. Effects of GD16-20 dosing were similar to those previously reported for GD14-18 dosing and included increased maternal liver weight, altered maternal serum lipid and thyroid hormone concentrations, and altered expression of peroxisome proliferator-activated receptor (PPAR) pathway genes in maternal and fetal livers. Dosing from GD8-PND2 produced similar effects as well as dose-responsive decreased pup birth weight (≥30 mg/kg), increased neonatal mortality (≥62.5 mg/kg), and increased pup liver weight (≥10 mg/kg). Histopathological evaluation of newborn pup livers indicated a marked reduction in glycogen stores and pups were hypoglycemic at birth. Quantitative gene expression analyses of F1 livers revealed significant alterations in genes related to glucose metabolism at birth and on GD20. Maternal serum and liver HFPO-DA concentrations were similar between dosing intervals, indicating rapid clearance, however dams dosed GD8 – PND2 had greater liver weight and gestational weight gain effects at lower doses than GD16-20 dosing, indicating the importance of exposure duration. Comparison of neonatal mortality dose–response curves between HFPO-DA and previously published perfluorooctane sulfonate (PFOS) data indicated that, based on serum concentration, the potency of these two PFAS are similar in the rat. Overall, HFPO-DA is a developmental toxicant in the rat and the spectrum of adverse effects is consistent with prior PFAS toxicity evaluations, such as PFOS and PFOA.

ACS Style

Justin M. Conley; Christy S. Lambright; Nicola Evans; James McCord; Mark J. Strynar; Donna Hill; Elizabeth Medlock-Kakaley; Vickie S. Wilson; L. Earl Gray. Hexafluoropropylene oxide-dimer acid (HFPO-DA or GenX) alters maternal and fetal glucose and lipid metabolism and produces neonatal mortality, low birthweight, and hepatomegaly in the Sprague-Dawley rat. Environment International 2020, 146, 106204 .

AMA Style

Justin M. Conley, Christy S. Lambright, Nicola Evans, James McCord, Mark J. Strynar, Donna Hill, Elizabeth Medlock-Kakaley, Vickie S. Wilson, L. Earl Gray. Hexafluoropropylene oxide-dimer acid (HFPO-DA or GenX) alters maternal and fetal glucose and lipid metabolism and produces neonatal mortality, low birthweight, and hepatomegaly in the Sprague-Dawley rat. Environment International. 2020; 146 ():106204.

Chicago/Turabian Style

Justin M. Conley; Christy S. Lambright; Nicola Evans; James McCord; Mark J. Strynar; Donna Hill; Elizabeth Medlock-Kakaley; Vickie S. Wilson; L. Earl Gray. 2020. "Hexafluoropropylene oxide-dimer acid (HFPO-DA or GenX) alters maternal and fetal glucose and lipid metabolism and produces neonatal mortality, low birthweight, and hepatomegaly in the Sprague-Dawley rat." Environment International 146, no. : 106204.

Journal article
Published: 29 September 2020 in Toxicological Sciences
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The U.S. EPA Endocrine Disruptor Screening Program utilizes data across the ToxCast/Tox21 high-throughput screening (HTS) programs to evaluate the biological effects of potential endocrine active substances. A potential limitation to the use of in vitro assay data in regulatory decision-making is the lack of coverage for xenobiotic metabolic processes. Both hepatic- and peripheral-tissue metabolism can yield metabolites that exhibit greater activity than the parent compound (bioactivation) or are inactive (bioinactivation) for a given biological target. Interpretation of biological effect data for both putative endocrine active substances, as well as other chemicals, screened in HTS assays may benefit from the addition of xenobiotic metabolic capabilities to decrease the uncertainty in predicting potential hazards to human health. The objective of this study was to develop an approach to retrofit existing HTS assays with hepatic metabolism. The Alginate Immobilization of Metabolic Enzymes (AIME) platform encapsulates hepatic S9 fractions in alginate microspheres attached to 96-well peg lids. Functional characterization across a panel of reference substrates for phase I cytochrome P450 enzymes revealed substrate depletion with expected metabolite accumulation. Performance of the AIME method in the VM7Luc estrogen receptor transactivation assay was evaluated across 15 reference chemicals and 48 test chemicals that yield metabolites previously identified as estrogen receptor active or inactive. The results demonstrate the utility of applying the AIME method for identification of false-positive and false-negative target assay effects, reprioritization of hazard based on metabolism-dependent bioactivity, and enhanced in vivo concordance with the rodent uterotrophic bioassay. Integration of the AIME metabolism method may prove useful for future biochemical and cell-based HTS applications.

ACS Style

Chad Deisenroth; Danica E DeGroot; Todd Zurlinden; Andrew Eicher; James Mccord; Mi-Young Lee; Paul Carmichael; Russell S Thomas. The Alginate Immobilization of Metabolic Enzymes Platform Retrofits an Estrogen Receptor Transactivation Assay With Metabolic Competence. Toxicological Sciences 2020, 178, 281 -301.

AMA Style

Chad Deisenroth, Danica E DeGroot, Todd Zurlinden, Andrew Eicher, James Mccord, Mi-Young Lee, Paul Carmichael, Russell S Thomas. The Alginate Immobilization of Metabolic Enzymes Platform Retrofits an Estrogen Receptor Transactivation Assay With Metabolic Competence. Toxicological Sciences. 2020; 178 (2):281-301.

Chicago/Turabian Style

Chad Deisenroth; Danica E DeGroot; Todd Zurlinden; Andrew Eicher; James Mccord; Mi-Young Lee; Paul Carmichael; Russell S Thomas. 2020. "The Alginate Immobilization of Metabolic Enzymes Platform Retrofits an Estrogen Receptor Transactivation Assay With Metabolic Competence." Toxicological Sciences 178, no. 2: 281-301.

Research article
Published: 22 September 2020 in Environmental Science & Technology Letters
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Per- and polyfluoroalkyl substances (PFAS) are a widespread, environmentally persistent class of anthropogenic chemicals that are widely used in industrial and consumer products and frequently detected in environmental media. Concerns over potential human health impacts from long-term exposure to legacy PFAS (long-chain perfluoroalkyl acids) resulted in the use of PFAS with alternative structures. Non-targeted environmental monitoring has been crucial in identifying the existence and transport of emerging PFAS in environmental media. Previous work in an industrially impacted region of southwestern New Jersey has shown consistently elevated levels of legacy PFAS, motivating additional examination by non-targeted mass spectrometry to identify emerging PFAS contamination. This study applied non-targeted analysis to water samples collected in Gloucester and Salem Counties in southwestern New Jersey, revealing the existence of a series of chloro-perfluoro-polyether carboxylates and related PFAS species, believed to originate from a regional, industrial PFAS user. There is sparse publicly available toxicity information for the emerging chemical species, but estimated concentrations exceeded the state drinking water standards for perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA). Non-targeted analysis was used to estimate the effectiveness of point-of-entry water treatment systems for removal of the emerging species and reduced the abundance of PFAS by >90%.

ACS Style

James P. McCord; Mark J. Strynar; John W. Washington; Erica L. Bergman; Sandra M. Goodrow. Emerging Chlorinated Polyfluorinated Polyether Compounds Impacting the Waters of Southwestern New Jersey Identified by Use of Nontargeted Analysis. Environmental Science & Technology Letters 2020, 7, 903 -908.

AMA Style

James P. McCord, Mark J. Strynar, John W. Washington, Erica L. Bergman, Sandra M. Goodrow. Emerging Chlorinated Polyfluorinated Polyether Compounds Impacting the Waters of Southwestern New Jersey Identified by Use of Nontargeted Analysis. Environmental Science & Technology Letters. 2020; 7 (12):903-908.

Chicago/Turabian Style

James P. McCord; Mark J. Strynar; John W. Washington; Erica L. Bergman; Sandra M. Goodrow. 2020. "Emerging Chlorinated Polyfluorinated Polyether Compounds Impacting the Waters of Southwestern New Jersey Identified by Use of Nontargeted Analysis." Environmental Science & Technology Letters 7, no. 12: 903-908.

Research article
Published: 07 September 2020 in Environmental Science & Technology
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Per- and polyfluoroalkyl substances (PFAS) are anthropogenic, globally distributed chemicals. Legacy PFAS, including perfluorooctane sulfonate (PFOS), have been regularly detected in marine fauna but little is known about their current levels or the presence of novel PFAS in seabirds. We measured 36 emerging and legacy PFAS in livers from 31 juvenile seabirds from Massachusetts Bay, Narragansett Bay, and the Cape Fear River Estuary (CFRE), USA. PFOS was the major legacy perfluoroalkyl acid present, making up 58% of concentrations observed across all habitats (range: 11 - 280 ng/g). Novel PFAS were confirmed in chicks hatched downstream of a fluoropolymer production site in the CFRE - a perfluorinated ether sulfonic acid (Nafion byproduct-2; range: 1 – 110 ng/g) and two perfluorinated ether carboxylic acids (PFO4DA and PFO5DoDA; PFO5DoDA range: 5 – 30 ng/g). PFOS was inversely associated with phospholipid content in livers from CFRE and Massachusetts Bay individuals, while ẟ13C, an indicator of marine vs. terrestrial foraging, was positively correlated with some long-chain PFAS in CFRE chick livers. These results detail concentrations of legacy and novel PFAS across different marine ecosystems along the US Atlantic East Coast. There is also an indication that seabird phospholipid dynamics are negatively impacted by PFAS, which should be further explored given the importance of lipids for seabirds.

ACS Style

Anna R. Robuck; Mark G. Cantwell; James P. Mccord; Lindsay M. Addison; Marisa Pfohl; Mark J. Strynar; Richard A McKinney; David R. Katz; David N. Wiley; Rainer Lohmann. Legacy and Novel Per- and Polyfluoroalkyl Substances in Juvenile Seabirds from the U.S. Atlantic Coast. Environmental Science & Technology 2020, 54, 12938 -12948.

AMA Style

Anna R. Robuck, Mark G. Cantwell, James P. Mccord, Lindsay M. Addison, Marisa Pfohl, Mark J. Strynar, Richard A McKinney, David R. Katz, David N. Wiley, Rainer Lohmann. Legacy and Novel Per- and Polyfluoroalkyl Substances in Juvenile Seabirds from the U.S. Atlantic Coast. Environmental Science & Technology. 2020; 54 (20):12938-12948.

Chicago/Turabian Style

Anna R. Robuck; Mark G. Cantwell; James P. Mccord; Lindsay M. Addison; Marisa Pfohl; Mark J. Strynar; Richard A McKinney; David R. Katz; David N. Wiley; Rainer Lohmann. 2020. "Legacy and Novel Per- and Polyfluoroalkyl Substances in Juvenile Seabirds from the U.S. Atlantic Coast." Environmental Science & Technology 54, no. 20: 12938-12948.

Research article
Published: 29 June 2020 in Environmental Science & Technology
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Introduction of oil and gas extraction wastewaters (OGWs) to surface water leads to elevated halide levels from geogenic bromide and iodide, as well as enhanced formation of brominated and iodinated disinfection by-products (DBPs) when treated. OGWs contain high levels of chemical additives used to optimize extraction activities, such as surfactants, which have the potential to serve as organic DBP precursors in OGW-impacted water sources. We report the first identification of olefin sulfonate surfactant-derived DBPs from laboratory-disinfected gas extraction wastewater. Over 300 sulfur-containing DBPs, with 43 unique molecular formulas, were found by high-resolution mass spectrometry (MS), following bench-scale chlor(am)ination. DBPs consisted of mostly brominated species, including bromohydrin sulfonates, dihalo-bromosulfonates, and bromosultone sulfonates, with chlorinated/iodinated analogues formed to a lesser extent. Disinfection of a commercial C12-olefin sulfonate surfactant mixture revealed dodecene sulfonate as a likely precursor for most detected DBPs; di-sulfur-containing DBPs, like bromosultone sulfonate and bromohydrin disulfonate, originated from olefin disulfonate species, present as side-products of olefin sulfonate production. Disinfection of wastewaters increased mammalian cytotoxicity several orders of magnitude, with chloraminated water being more toxic. This finding is important to OGW-impacted source waters because drinking water plants with high-bromide source waters may switch to chloramination to meet DBP regulations.

ACS Style

Hannah K. Liberatore; Danielle C. Westerman; Joshua M. Allen; Michael J. Plewa; Elizabeth D. Wagner; Amy M. McKenna; Chad R. Weisbrod; James P. Mccord; Richard J. Liberatore; David B. Burnett; Leslie H. Cizmas; Susan D. Richardson. High-Resolution Mass Spectrometry Identification of Novel Surfactant-Derived Sulfur-Containing Disinfection Byproducts from Gas Extraction Wastewater. Environmental Science & Technology 2020, 54, 9374 -9386.

AMA Style

Hannah K. Liberatore, Danielle C. Westerman, Joshua M. Allen, Michael J. Plewa, Elizabeth D. Wagner, Amy M. McKenna, Chad R. Weisbrod, James P. Mccord, Richard J. Liberatore, David B. Burnett, Leslie H. Cizmas, Susan D. Richardson. High-Resolution Mass Spectrometry Identification of Novel Surfactant-Derived Sulfur-Containing Disinfection Byproducts from Gas Extraction Wastewater. Environmental Science & Technology. 2020; 54 (15):9374-9386.

Chicago/Turabian Style

Hannah K. Liberatore; Danielle C. Westerman; Joshua M. Allen; Michael J. Plewa; Elizabeth D. Wagner; Amy M. McKenna; Chad R. Weisbrod; James P. Mccord; Richard J. Liberatore; David B. Burnett; Leslie H. Cizmas; Susan D. Richardson. 2020. "High-Resolution Mass Spectrometry Identification of Novel Surfactant-Derived Sulfur-Containing Disinfection Byproducts from Gas Extraction Wastewater." Environmental Science & Technology 54, no. 15: 9374-9386.

Report
Published: 04 June 2020 in Science
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The toxicity and environmental persistence of anthropogenic per- and poly-fluoroalkyl substances (PFAS) are of global concern. To address legacy PFAS concerns in the United States, industry developed numerous replacement PFAS that commonly are treated as confidential information. To investigate the distribution of PFAS in New Jersey, soils collected from across the state were subjected to nontargeted mass-spectral analyses. Ten chloroperfluoropolyether carboxylates were tentatively identified, with at least three congeners in all samples. Nine congeners are ≥(CF2)7. Distinct chemical formulas and structures, as well as geographic distribution, suggest airborne transport from an industrial source. Lighter congeners dispersed more widely than heavier congeners, with the most widely dispersed detected in an in-stock New Hampshire sample. Additional data were used to develop a legacy-PFAS fingerprint for historical PFAS sources in New Jersey.

ACS Style

John W. Washington; Charlita G. Rosal; James P. McCord; Mark J. Strynar; Andrew B. Lindstrom; Erica L. Bergman; Sandra M. Goodrow; Haile K. Tadesse; Andrew N. Pilant; Benjamin J. Washington; Mary J. Davis; Brittany G. Stuart; Thomas M. Jenkins. Nontargeted mass-spectral detection of chloroperfluoropolyether carboxylates in New Jersey soils. Science 2020, 368, 1103 -1107.

AMA Style

John W. Washington, Charlita G. Rosal, James P. McCord, Mark J. Strynar, Andrew B. Lindstrom, Erica L. Bergman, Sandra M. Goodrow, Haile K. Tadesse, Andrew N. Pilant, Benjamin J. Washington, Mary J. Davis, Brittany G. Stuart, Thomas M. Jenkins. Nontargeted mass-spectral detection of chloroperfluoropolyether carboxylates in New Jersey soils. Science. 2020; 368 (6495):1103-1107.

Chicago/Turabian Style

John W. Washington; Charlita G. Rosal; James P. McCord; Mark J. Strynar; Andrew B. Lindstrom; Erica L. Bergman; Sandra M. Goodrow; Haile K. Tadesse; Andrew N. Pilant; Benjamin J. Washington; Mary J. Davis; Brittany G. Stuart; Thomas M. Jenkins. 2020. "Nontargeted mass-spectral detection of chloroperfluoropolyether carboxylates in New Jersey soils." Science 368, no. 6495: 1103-1107.

Research article
Published: 18 May 2020 in Environmental Science & Technology Letters
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Per- and polyfluorinated alkyl substances (PFAS) are of significant interest because of their prevalence and environmental persistence. Further, for many PFAS, including fluorinated ethers, such as hexafluoropropylene oxide dimer acid (HFPO-DA, or the parent acid of “GenX”), toxicological data are sparse. In general, in vitro testing frequently uses dimethyl sulfoxide (DMSO) as a carrier solvent due to its low toxicity, solubility across vast chemical space, and permeation across biological barriers. For PFAS, laboratory practice has assumed that the materials are stable across a wide range of solvents, pHs, and temperatures. In this study, HFPO-DA stability was evaluated with DMSO and other commonly used solvents to determine each solvent’s suitability for use in toxicity assays. The formation of HFPO-DA’s degradation product, heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether (Fluoroether E-1), was monitored by headspace gas chromatography-mass spectrometry (GC-MS) over time. These experiments revealed degradation of HFPO-DA to Fluoroether E-1 in DMSO and other aprotic, polar solvents, with half-lives on the order of hours (1 h, 1.25 h, and 5.2 h for DMSO, acetone, and acetonitrile, respectively). This rapid degradation suggests the need for caution when performing or using data from toxicity assessments on HFPO-DA and closely related PFAS compounds.

ACS Style

Hannah K. Liberatore; Stephen R. Jackson; Mark J. Strynar; James P. Mccord. Solvent Suitability for HFPO-DA (“GenX” Parent Acid) in Toxicological Studies. Environmental Science & Technology Letters 2020, 7, 477 -481.

AMA Style

Hannah K. Liberatore, Stephen R. Jackson, Mark J. Strynar, James P. Mccord. Solvent Suitability for HFPO-DA (“GenX” Parent Acid) in Toxicological Studies. Environmental Science & Technology Letters. 2020; 7 (7):477-481.

Chicago/Turabian Style

Hannah K. Liberatore; Stephen R. Jackson; Mark J. Strynar; James P. Mccord. 2020. "Solvent Suitability for HFPO-DA (“GenX” Parent Acid) in Toxicological Studies." Environmental Science & Technology Letters 7, no. 7: 477-481.

Paper in forefront
Published: 25 April 2020 in Analytical and Bioanalytical Chemistry
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Non-targeted analysis (NTA) methods are being increasingly used to aid in the identification of unknown compounds in the environment, a problem that has challenged environmental chemists for decades. Despite its increased use, quality assurance practices for NTA have not been well established. Furthermore, capabilities and limitations of certain NTA methods have not been thoroughly evaluated. Standard reference material dust (SRM 2585) was used here to evaluate the ability of NTA to identify previously reported compounds, as well as a suite of 365 chemicals that were spiked at various stages of the analytical procedure. Analysis of the unaltered SRM 2585 extracts revealed that several previously reported compounds can be identified by NTA, and that correct identification was dependent on concentration. A manual inspection of unknown features in SRM 2585 revealed the presence of two chlorinated and fluorinated compounds in high abundance, likely precursors to perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS). A retrospective analysis of data from the American Healthy Homes Survey revealed that these compounds were present in 42% of sampled homes. Spiking the dust at various stages of sample preparation revealed losses from extraction, cleanup, and instrumental analysis; the log Kow for individual compounds influenced the overall recovery levels but no pattern could be discerned from the various degrees of interference that the matrix had on the ionization efficiency of the spiked chemicals. Analysis of the matrix-free chemical mixture at low, medium, and high concentrations led to more correct identifications than analysis at one, very high concentration. Varying the spiked amount and identifying reported compounds at known concentrations allowed an estimation of the lower limits of identification (LOIs) for NTA, analogous to limits of detection in targeted analysis. The LOIs were much lower than levels in dust that would be likely to cause bioactivity in humans, indicating that NTA is useful for identifying and monitoring compounds that may be of toxicological concern. Graphical abstract

ACS Style

Seth R. Newton; Jon R. Sobus; Elin M. Ulrich; Randolph R. Singh; Alex Chao; James McCord; Sarah Laughlin-Toth; Mark Strynar. Examining NTA performance and potential using fortified and reference house dust as part of EPA’s Non-Targeted Analysis Collaborative Trial (ENTACT). Analytical and Bioanalytical Chemistry 2020, 412, 4221 -4233.

AMA Style

Seth R. Newton, Jon R. Sobus, Elin M. Ulrich, Randolph R. Singh, Alex Chao, James McCord, Sarah Laughlin-Toth, Mark Strynar. Examining NTA performance and potential using fortified and reference house dust as part of EPA’s Non-Targeted Analysis Collaborative Trial (ENTACT). Analytical and Bioanalytical Chemistry. 2020; 412 (18):4221-4233.

Chicago/Turabian Style

Seth R. Newton; Jon R. Sobus; Elin M. Ulrich; Randolph R. Singh; Alex Chao; James McCord; Sarah Laughlin-Toth; Mark Strynar. 2020. "Examining NTA performance and potential using fortified and reference house dust as part of EPA’s Non-Targeted Analysis Collaborative Trial (ENTACT)." Analytical and Bioanalytical Chemistry 412, no. 18: 4221-4233.

Journal article
Published: 01 April 2020 in Environmental Health Perspectives
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Background:Per- and polyfluoroalkyl substances (PFAS) are a diverse class of industrial chemicals with widespread environmental occurrence. Exposure to long-chain PFAS is associated with developmental toxicity, prompting their replacement with short-chain and fluoroether compounds. There is growing public concern over the safety of replacement PFAS.Objective:We aimed to group PFAS based on shared toxicity phenotypes.Methods:Zebrafish were developmentally exposed to 4,8-dioxa-3H-perfluorononanoate (ADONA), perfluoro-2-propoxypropanoic acid (GenX Free Acid), perfluoro-3,6-dioxa-4-methyl-7-octene-1-sulfonic acid (PFESA1), perfluorohexanesulfonic acid (PFHxS), perfluorohexanoic acid (PFHxA), perfluoro-n-octanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), or 0.4% dimethyl sulfoxide (DMSO) daily from 0–5 d post fertilization (dpf). At 6 dpf, developmental toxicity and developmental neurotoxicity assays were performed, and targeted analytical chemistry was used to measure media and tissue doses. To test whether aliphatic sulfonic acid PFAS cause the same toxicity phenotypes, perfluorobutanesulfonic acid (PFBS; 4-carbon), perfluoropentanesulfonic acid (PFPeS; 5-carbon), PFHxS (6-carbon), perfluoroheptanesulfonic acid (PFHpS; 7-carbon), and PFOS (8-carbon) were evaluated.Results:PFHxS or PFOS exposure caused failed swim bladder inflation, abnormal ventroflexion of the tail, and hyperactivity at nonteratogenic concentrations. Exposure to PFHxA resulted in a unique hyperactivity signature. ADONA, PFESA1, or PFOA exposure resulted in detectable levels of parent compound in larval tissue but yielded negative toxicity results. GenX was unstable in DMSO, but stable and negative for toxicity when diluted in deionized water. Exposure to PFPeS, PFHxS, PFHpS, or PFOS resulted in a shared toxicity phenotype characterized by body axis and swim bladder defects and hyperactivity.Conclusions:All emerging fluoroether PFAS tested were negative for evaluated outcomes. Two unique toxicity signatures were identified arising from structurally dissimilar PFAS. Among sulfonic acid aliphatic PFAS, chemical potencies were correlated with increasing carbon chain length for developmental neurotoxicity, but not developmental toxicity. This study identified relationships between chemical structures and in vivo phenotypes that may arise from shared mechanisms of PFAS toxicity. These data suggest that developmental neurotoxicity is an important end point to consider for this class of widely occurring environmental chemicals. https://doi.org/10.1289/EHP5843

ACS Style

Shaza Gaballah; Adam Swank; Jon R. Sobus; Xia Meng Howey; Judith Schmid; Tara Catron; James Mccord; Erin Hines; Mark Strynar; Tamara Tal. Evaluation of Developmental Toxicity, Developmental Neurotoxicity, and Tissue Dose in Zebrafish Exposed to GenX and Other PFAS. Environmental Health Perspectives 2020, 128, 047005 .

AMA Style

Shaza Gaballah, Adam Swank, Jon R. Sobus, Xia Meng Howey, Judith Schmid, Tara Catron, James Mccord, Erin Hines, Mark Strynar, Tamara Tal. Evaluation of Developmental Toxicity, Developmental Neurotoxicity, and Tissue Dose in Zebrafish Exposed to GenX and Other PFAS. Environmental Health Perspectives. 2020; 128 (4):047005.

Chicago/Turabian Style

Shaza Gaballah; Adam Swank; Jon R. Sobus; Xia Meng Howey; Judith Schmid; Tara Catron; James Mccord; Erin Hines; Mark Strynar; Tamara Tal. 2020. "Evaluation of Developmental Toxicity, Developmental Neurotoxicity, and Tissue Dose in Zebrafish Exposed to GenX and Other PFAS." Environmental Health Perspectives 128, no. 4: 047005.

Journal article
Published: 07 February 2020 in Environment International
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Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemicals of concern that persist in the environment. Environmental monitoring revealed high concentrations of hexafluoropropylene oxide dimer acid (HFPO-DA) and other novel PFAS in the lower Cape Fear River; however, there is limited information on PFAS exposures and effects of this contamination on aquatic biota. Serum concentrations of 23 PFAS in Striped Bass (Morone saxatilis) from the Cape Fear River (n = 58) and a reference population from an aquaculture laboratory on the Pamlico/Tar watershed (n = 29) were quantified using liquid chromatography and high-resolution mass spectrometry, and correlations between PFAS concentrations and health-related serum biomarkers were evaluated. Perfluorooctane sulfonate, the predominant PFAS in Cape Fear River Striped Bass serum, was detectable in every sample with serum concentrations reaching 977 ng/mL. Perfluorononanoic and perfluorodecanoic acid were also detected in all samples, with perfluorohexanesulfonic acid present in >98% of the samples. HFPO-DA (range <0.24–5.85 ng/mL) and Nafion byproduct 2 (range <0.2–1.03 ng/mL) were detected in 48% and 78% of samples, respectively. The mean total PFAS concentration found in domestic Striped Bass raised in well-water under controlled aquaculture conditions was 40 times lower, with HPFO-DA detected in 10% of the samples, and Nafion byproduct 2 was not detected. The elevated PFAS concentrations found in the Cape Fear River Striped Bass were associated with biomarkers of alterations in the liver and immune system.

ACS Style

T.C. Guillette; James McCord; Matthew Guillette; M.E. Polera; Kyle T. Rachels; Clint Morgeson; Nadine Kotlarz; Detlef R.U. Knappe; Benjamin Reading; Mark Strynar; Scott M. Belcher. Elevated levels of per- and polyfluoroalkyl substances in Cape Fear River Striped Bass (Morone saxatilis) are associated with biomarkers of altered immune and liver function. Environment International 2020, 136, 105358 -105358.

AMA Style

T.C. Guillette, James McCord, Matthew Guillette, M.E. Polera, Kyle T. Rachels, Clint Morgeson, Nadine Kotlarz, Detlef R.U. Knappe, Benjamin Reading, Mark Strynar, Scott M. Belcher. Elevated levels of per- and polyfluoroalkyl substances in Cape Fear River Striped Bass (Morone saxatilis) are associated with biomarkers of altered immune and liver function. Environment International. 2020; 136 ():105358-105358.

Chicago/Turabian Style

T.C. Guillette; James McCord; Matthew Guillette; M.E. Polera; Kyle T. Rachels; Clint Morgeson; Nadine Kotlarz; Detlef R.U. Knappe; Benjamin Reading; Mark Strynar; Scott M. Belcher. 2020. "Elevated levels of per- and polyfluoroalkyl substances in Cape Fear River Striped Bass (Morone saxatilis) are associated with biomarkers of altered immune and liver function." Environment International 136, no. : 105358-105358.

Journal article
Published: 01 February 2020 in Environmental Health Perspectives
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Background:Perfluorooctanoic acid (PFOA) is a poly- and perfluoroalkyl substance (PFAS) associated with adverse pregnancy outcomes in mice and humans, but little is known regarding one of its replacements, hexafluoropropylene oxide dimer acid (HFPO-DA, referred to here as GenX), both of which have been reported as contaminants in drinking water.Objectives:We compared the toxicity of PFOA and GenX in pregnant mice and their developing embryo–placenta units, with a specific focus on the placenta as a hypothesized target.Methods:Pregnant CD-1 mice were exposed daily to PFOA (0, 1, or 5mg/kg) or GenX (0, 2, or 10mg/kg) via oral gavage from embryonic day (E) 1.5 to 11.5 or 17.5 to evaluate exposure effects on the dam and embryo–placenta unit. Gestational weight gain (GWG), maternal clinical chemistry, maternal liver histopathology, placental histopathology, embryo weight, placental weight, internal chemical dosimetry, and placental thyroid hormone levels were determined.Results:Exposure to GenX or PFOA resulted in increased GWG, with increase in weight most prominent and of shortest latency with 10mg/kg/d GenX exposure. Embryo weight was significantly lower after exposure to 5mg/kg/d PFOA (9.4% decrease relative to controls). Effect sizes were similar for higher doses (5mg/kg/d PFOA and 10mg/kg/d GenX) and lower doses (1mg/kg/d PFOA and 2mg/kg/d GenX), including higher maternal liver weights, changes in liver histopathology, higher placental weights and embryo–placenta weight ratios, and greater incidence of placental abnormalities relative to controls. Histopathological features in placentas suggested that PFOA and GenX may exhibit divergent mechanisms of toxicity in the embryo–placenta unit, whereas PFOA- and GenX-exposed livers shared a similar constellation of adverse pathological features.Conclusions:Gestational exposure to GenX recapitulated many documented effects of PFOA in CD-1 mice, regardless of its much shorter reported half-life; however, adverse effects toward the placenta appear to have compound-specific signatures. https://doi.org/10.1289/EHP6233

ACS Style

Bevin E. Blake; Harlie A. Cope; Samantha M. Hall; Robert D. Keys; Beth W. Mahler; James McCord; Brittany Scott; Heather M. Stapleton; Mark J. Strynar; Susan A. Elmore; Suzanne E. Fenton. Evaluation of Maternal, Embryo, and Placental Effects in CD-1 Mice following Gestational Exposure to Perfluorooctanoic Acid (PFOA) or Hexafluoropropylene Oxide Dimer Acid (HFPO-DA or GenX). Environmental Health Perspectives 2020, 128, 027006 .

AMA Style

Bevin E. Blake, Harlie A. Cope, Samantha M. Hall, Robert D. Keys, Beth W. Mahler, James McCord, Brittany Scott, Heather M. Stapleton, Mark J. Strynar, Susan A. Elmore, Suzanne E. Fenton. Evaluation of Maternal, Embryo, and Placental Effects in CD-1 Mice following Gestational Exposure to Perfluorooctanoic Acid (PFOA) or Hexafluoropropylene Oxide Dimer Acid (HFPO-DA or GenX). Environmental Health Perspectives. 2020; 128 (2):027006.

Chicago/Turabian Style

Bevin E. Blake; Harlie A. Cope; Samantha M. Hall; Robert D. Keys; Beth W. Mahler; James McCord; Brittany Scott; Heather M. Stapleton; Mark J. Strynar; Susan A. Elmore; Suzanne E. Fenton. 2020. "Evaluation of Maternal, Embryo, and Placental Effects in CD-1 Mice following Gestational Exposure to Perfluorooctanoic Acid (PFOA) or Hexafluoropropylene Oxide Dimer Acid (HFPO-DA or GenX)." Environmental Health Perspectives 128, no. 2: 027006.

Rapid communication
Published: 02 October 2019 in Environmental Science & Technology Letters
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Per- and polyfluoroalkyl substances (PFASs) are widely used anthropogenic chemicals. The PFAS class includes almost 5000 registered compounds, but analytical methods are lacking for most PFASs. The total oxidizable precursor (TOP) assay was developed to indirectly quantify unknown PFASs that are precursors to commonly measured perfluoroalkyl acids. To understand the behavior of recently identified per- and polyfluoroalkyl ether acids (PFEAs), including fluorinated replacements and manufacturing byproducts, we determined the fate of 15 PFEAs in the TOP assay. Ten perfluoroalkyl ether acids and a chlorinated polyfluoroalkyl ether acid (F-53B) were stable in the TOP assay and represent terminal products that are likely as persistent as historically used PFASs. Adding perfluoroalkyl ether acids and F-53B to the target analyte list for the TOP assay is recommended to capture a higher percentage of the total PFAS concentration in environmental samples. In contrast, polyfluoroalkyl ether acids with a -O-CFH- moiety were oxidized, typically to products that could not be identified by liquid chromatography and high-resolution mass spectrometry. Application of the TOP assay in its proposed enhanced form revealed high levels of PFEAs, the presence of precursors that form perfluoroalkyl carboxylic acids, and the absence of precursors that form PFEAs in surface water impacted by PFAS-containing wastewater discharges.

ACS Style

Chuhui Zhang; Zachary R. Hopkins; James McCord; Mark J. Strynar; Detlef R. U. Knappe. Fate of Per- and Polyfluoroalkyl Ether Acids in the Total Oxidizable Precursor Assay and Implications for the Analysis of Impacted Water. Environmental Science & Technology Letters 2019, 6, 662 -668.

AMA Style

Chuhui Zhang, Zachary R. Hopkins, James McCord, Mark J. Strynar, Detlef R. U. Knappe. Fate of Per- and Polyfluoroalkyl Ether Acids in the Total Oxidizable Precursor Assay and Implications for the Analysis of Impacted Water. Environmental Science & Technology Letters. 2019; 6 (11):662-668.

Chicago/Turabian Style

Chuhui Zhang; Zachary R. Hopkins; James McCord; Mark J. Strynar; Detlef R. U. Knappe. 2019. "Fate of Per- and Polyfluoroalkyl Ether Acids in the Total Oxidizable Precursor Assay and Implications for the Analysis of Impacted Water." Environmental Science & Technology Letters 6, no. 11: 662-668.

Accepted manuscript
Published: 10 September 2019 in Journal of Breath Research
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Early identification of disease onset is regarded as an important factor for successful medical intervention. However, cancer and other long-term latency diseases are rare and may take years to manifest clinically. As such, there are no gold standards with which to immediately validate proposed pre-clinical screening methodologies. There is evidence that dogs can sort samples reproducibly into yes/no categories based on case-control training, but the basis of their decisions is unknown. Because dogs are sniffing air, the distinguishing chemicals must be either in the gas-phase or attached to aerosols and/or airborne particles. Recent biomonitoring research has shown how to extract and analyze semi- and non-volatile compounds from human breath in exhaled condensates and aerosols. Further research has shown that exhaled aerosols can be directly collected on standard hospital-style olefin polypropylene masks and that these masks can be used as a simple sampling scheme for canine screening. In this article, detailed liquid chromatography-high resolution mass spectrometry (LC-HR-MS) with Orbitrap instrumentation and gas chromatography-mass spectrometry (GC-MS) analyses were performed on two sets of masks sorted by consensus of a four-dog cohort as either cancer or control. Specifically, after sorting by the dogs, sample masks were cut into multiple sections and extracted for LC-MS and GC-MS non-targeted analyses. Extracts were also analyzed for human cytokines, confirming the presence of human aerosol content above levels in blank masks. In preliminary evaluations, 345 and 44 high quality chemical features were detected by LC-MS and GC-MS analyses, respectively. These features were used to develop provisional orthogonal projection to latent structures-discriminant analysis (OPLS-DA) models to determine if the samples classified as cancer (case) or non-cancer (control) by the dogs could be separated into the same groups using analytical instrumentation. While the OPLS-DA model for the LC-HR-MS data was able to separate the two groups with statistical significance, although weak explanatory power, the GC-MS model was not found to be significant. These results suggest that the dogs may rely more on the less volatile compounds from breath aerosol that were analyzed by LC-HR-MS than the more volatile compounds observed by GC-MS to sort mask samples into groups. These results provide justification for more expansive studies in the future that aim to characterize specific chemical features, and the role(s) of these features in maintaining homeostatic biological processes.

ACS Style

Joachim D Pleil; M Ariel Geer Wallace; James Mccord; Michael C Madden; Jon Sobus; Glenn Ferguson. How do cancer-sniffing dogs sort biological samples? Exploring case-control samples with non-targeted LC-Orbitrap, GC-MS, and immunochemistry methods. Journal of Breath Research 2019, 14, 016006 .

AMA Style

Joachim D Pleil, M Ariel Geer Wallace, James Mccord, Michael C Madden, Jon Sobus, Glenn Ferguson. How do cancer-sniffing dogs sort biological samples? Exploring case-control samples with non-targeted LC-Orbitrap, GC-MS, and immunochemistry methods. Journal of Breath Research. 2019; 14 (1):016006.

Chicago/Turabian Style

Joachim D Pleil; M Ariel Geer Wallace; James Mccord; Michael C Madden; Jon Sobus; Glenn Ferguson. 2019. "How do cancer-sniffing dogs sort biological samples? Exploring case-control samples with non-targeted LC-Orbitrap, GC-MS, and immunochemistry methods." Journal of Breath Research 14, no. 1: 016006.

Journal article
Published: 05 September 2019 in Toxicological Sciences
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Microbiota regulate important physiologic processes during early host development. They also biotransform xenobiotics and serve as key intermediaries for chemical exposure. Antimicrobial agents in the environment may disrupt these complex interactions and alter key metabolic functions provided by host-associated microbiota. To examine the role of microbiota in xenobiotic metabolism, we exposed zebrafish larvae to the antimicrobial agent triclosan. Conventionally colonized (CC), microbe-free axenic (AX), or axenic colonized on day 1 (AC1) zebrafish were exposed to 0.16-0.30 uM triclosan or vehicle on days 1, 6, 7, 8, and 9 days post fertilization (dpf). After 6 dpf and 10 dpf, host-associated microbial community structure and putative function were assessed by 16S rRNA gene sequencing. At 10 dpf, triclosan exposure selected for bacterial taxa, including Rheinheimera. Triclosan-selected microbes were predicted to be enriched in pathways related to mechanisms of antibiotic resistance, sulfonation, oxidative stress, and drug metabolism. Furthermore, at 10 dpf, colonized zebrafish contained 2.5-3 times more triclosan relative to AX larvae. Non-targeted chemical analysis revealed that, relative to AX larvae, both cohorts of colonized larvae showed elevations in 23 chemical features, including parent triclosan and putative triclosan sulfate. Taken together, these data suggest that triclosan exposure selects for microbes that harbor the capacity to biotransform triclosan into chemical metabolites with unknown toxicity profiles. More broadly, these data support the concept that microbiota modify the toxicokinetics of xenobiotic exposure.

ACS Style

Chelsea A Weitekamp; Drake Phelps; Adam Swank; James Mccord; Jon R Sobus; Tara Catron; Scott Keely; Nichole Brinkman; Todd Zurlinden; Emily Wheaton; Mark Strynar; Charlene McQueen; Charles E Wood; Tamara Tal. Triclosan-selected host-associated microbiota perform xenobiotic biotransformations in larval zebrafish. Toxicological Sciences 2019, 172, 109 -122.

AMA Style

Chelsea A Weitekamp, Drake Phelps, Adam Swank, James Mccord, Jon R Sobus, Tara Catron, Scott Keely, Nichole Brinkman, Todd Zurlinden, Emily Wheaton, Mark Strynar, Charlene McQueen, Charles E Wood, Tamara Tal. Triclosan-selected host-associated microbiota perform xenobiotic biotransformations in larval zebrafish. Toxicological Sciences. 2019; 172 (1):109-122.

Chicago/Turabian Style

Chelsea A Weitekamp; Drake Phelps; Adam Swank; James Mccord; Jon R Sobus; Tara Catron; Scott Keely; Nichole Brinkman; Todd Zurlinden; Emily Wheaton; Mark Strynar; Charlene McQueen; Charles E Wood; Tamara Tal. 2019. "Triclosan-selected host-associated microbiota perform xenobiotic biotransformations in larval zebrafish." Toxicological Sciences 172, no. 1: 109-122.

Journal article
Published: 13 July 2019 in Science of The Total Environment
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Much research has assessed organic chemicals of concern (COCs) in municipal wastewater and receiving waters, but few studies have examined COCs in land treatment systems. Many prior studies have implemented targeted methods that quantify a relatively small fraction of COCs present in wastewater and receiving waters. This study used suspect screening to assess chemical features in ground- and surface waters from a watershed where secondary-treated wastewater is irrigated onto 900 ha of temperate forest, offering a more holistic view of chemicals that contribute to the exposome. Chemical features were prioritized by abundance and ToxPi scoring across seasonal sampling events to determine if the forest-water reuse system contributed to the chemical exposome of ground- and surface waters. The number of chemical features detected in wastewater was usually higher than on- and off-site ground- and surface waters; in wastewater, chemical features trended with precipitation in which greater numbers of features were detected in months with low precipitation. The number of chemical features detected in off- and on-site waters was similar. The lower overlap between chemical features found in wastewater and downstream surface waters, along with the similar numbers of features being detected in upstream and downstream surface waters, suggests that though wastewater may be a source of chemicals to ground and surface waters on-site, dissipation of wastewater-derived features (in number and peak area abundance) likely occurs with limited off-site surface water export by the forested land treatment system. Further, the numbers of features detected on site and the overlap between wastewater and surface waters did not increase during periods of low rainfall, counter to our initial expectations. The chemical features tentatively identified in this watershed appear common to features identified in other studies, warranting further examination on the potential for resulting impacts of these on humans and the environment.

ACS Style

Melanie L. Hedgespeth; Nancy Gibson; James McCord; Mark Strynar; Damian Shea; Elizabeth Guthrie Nichols. Suspect screening and prioritization of chemicals of concern (COCs) in a forest-water reuse system watershed. Science of The Total Environment 2019, 694, 133378 .

AMA Style

Melanie L. Hedgespeth, Nancy Gibson, James McCord, Mark Strynar, Damian Shea, Elizabeth Guthrie Nichols. Suspect screening and prioritization of chemicals of concern (COCs) in a forest-water reuse system watershed. Science of The Total Environment. 2019; 694 ():133378.

Chicago/Turabian Style

Melanie L. Hedgespeth; Nancy Gibson; James McCord; Mark Strynar; Damian Shea; Elizabeth Guthrie Nichols. 2019. "Suspect screening and prioritization of chemicals of concern (COCs) in a forest-water reuse system watershed." Science of The Total Environment 694, no. : 133378.

Journal article
Published: 08 May 2019 in Scientific Reports
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Estrogenic chemicals are widespread environmental contaminants associated with diverse health and ecological effects. During early vertebrate development, estrogen receptor signaling is critical for many different physiologic responses, including nervous system function. Recently, host-associated microbiota have been shown to influence neurodevelopment. Here, we hypothesized that microbiota may biotransform exogenous 17-βestradiol (E2) and modify E2 effects on swimming behavior. Colonized zebrafish were continuously exposed to non-teratogenic E2 concentrations from 1 to 10 days post-fertilization (dpf). Changes in microbial composition and predicted metagenomic function were evaluated. Locomotor activity was assessed in colonized and axenic (microbe-free) zebrafish exposed to E2 using a standard light/dark behavioral assay. Zebrafish tissue was collected for chemistry analyses. While E2 exposure did not alter microbial composition or putative function, colonized E2-exposed larvae showed reduced locomotor activity in the light, in contrast to axenic E2-exposed larvae, which exhibited normal behavior. Measured E2 concentrations were significantly higher in axenic relative to colonized zebrafish. Integrated peak area for putative sulfonated and glucuronidated E2 metabolites showed a similar trend. These data demonstrate that E2 locomotor effects in the light phase are dependent on the presence of microbiota and suggest that microbiota influence chemical E2 toxicokinetics. More broadly, this work supports the concept that microbial colonization status may influence chemical toxicity.

ACS Style

Tara R. Catron; Adam Swank; Leah C. Wehmas; Drake Phelps; Scott P. Keely; Nichole E. Brinkman; James McCord; Randolph Singh; Jon Sobus; Charles E. Wood; Mark Strynar; Emily Wheaton; Tamara Tal. Microbiota alter metabolism and mediate neurodevelopmental toxicity of 17β-estradiol. Scientific Reports 2019, 9, 1 -15.

AMA Style

Tara R. Catron, Adam Swank, Leah C. Wehmas, Drake Phelps, Scott P. Keely, Nichole E. Brinkman, James McCord, Randolph Singh, Jon Sobus, Charles E. Wood, Mark Strynar, Emily Wheaton, Tamara Tal. Microbiota alter metabolism and mediate neurodevelopmental toxicity of 17β-estradiol. Scientific Reports. 2019; 9 (1):1-15.

Chicago/Turabian Style

Tara R. Catron; Adam Swank; Leah C. Wehmas; Drake Phelps; Scott P. Keely; Nichole E. Brinkman; James McCord; Randolph Singh; Jon Sobus; Charles E. Wood; Mark Strynar; Emily Wheaton; Tamara Tal. 2019. "Microbiota alter metabolism and mediate neurodevelopmental toxicity of 17β-estradiol." Scientific Reports 9, no. 1: 1-15.