@article {275, title = {Emerging investigator series: nontargeted screening of aryl hydrocarbon receptor agonists in endangered beluga whales from the St. Lawrence Estuary: beyond legacy contaminants.}, journal = {Environ Sci Process Impacts}, volume = {26}, year = {2024}, month = {2024 Sep 18}, pages = {1451-1464}, abstract = {

The elevated concentrations of organohalogen contaminants in the endangered St. Lawrence Estuary (SLE) belugas have prompted the hypothesis that aryl hydrocarbon receptor (AhR) activity may be a contributor towards their potential adverse effects. While indirect associations between AhR and contaminant levels have been reported in SLE beluga tissues, AhR activity was never directly measured. Using bioassays and nontargeted analysis, this study contrasted AhR activity and agonist profiles between pooled tissue extracts of endangered SLE and non-threatened Arctic belugas. Tissue extracts of SLE belugas exhibited significantly higher overall AhR activity than that of Arctic belugas, with a 2000s SLE beluga liver extract exerting significantly higher activity than blubber extracts of SLE and Arctic belugas from the same time period. Contrary to our expectations, well-known AhR agonists detected by nontargeted analysis, including polychlorinated biphenyls (PCBs), were only minor contributors to the observed AhR activity. Instead, Tox21 suspect screening identified more polar chemicals, such as dyes and natural indoles, as potential contributors. Notably, the natural product bromoindole was selectively detected in SLE beluga liver at high abundance and was further confirmed as an AhR agonist. These findings highlighted the significance of the AhR-mediated toxicity pathway in belugas and underscored the importance of novel AhR agonists, particularly polar compounds, in its induction.

}, keywords = {Animals, Beluga Whale, Endangered Species, Environmental Monitoring, Estuaries, Liver, Polychlorinated Biphenyls, Receptors, Aryl Hydrocarbon, Water Pollutants, Chemical}, issn = {2050-7895}, doi = {10.1039/d4em00243a}, author = {Barrett, Holly and Sun, Jianxian and Chen, Yuhao and Yang, Diwen and Verreault, Jonathan and Houde, Magali and Wania, Frank and Peng, Hui} } @article {269, title = {Identification of environmental and methodological factors driving variability of Pepper Mild Mottle Virus (PMMoV) across three wastewater treatment plants in the City of Toronto.}, journal = {Sci Total Environ}, volume = {932}, year = {2024}, month = {2024 Jul 01}, pages = {172917}, abstract = {

PMMoV has been widely used to normalize the concentration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA, influenza, and respiratory syncytial virus (RSV) to account for variations in the fecal content of wastewater. PMMoV is also used as an internal RNA recovery control for wastewater-based epidemiology (WBE) tests. While potentially useful for the interpretation of WBE data, previous studies have suggested that PMMoV concentration can be affected by various physico-chemical characteristics of wastewater. There is also the possibility that laboratory methods, particularly the variability in centrifugation steps to remove supernatant from pellets can cause PMMoV variability. The goal of this study is to improve our understanding of the main drivers of PMMoV variability by assessing the relationship between PMMoV concentration, the physico-chemical characteristics of wastewater, and the methodological approach for concentrating wastewater samples. We analyzed 24-hour composite wastewater samples collected from the influent stream of three wastewater treatment plants (WWTPs) located in the City of Toronto, Ontario, Canada. Samples were collected 3 to 5 times per week starting from the beginning of March 2021 to mid-July 2023. The influent flow rate was used to partition the data into wet and dry weather conditions. Physico-chemical characteristics (e.g., total suspended solids (TSS), biological oxygen demand (BOD), alkalinity, electrical conductivity (EC), and ammonia (NH)) of the raw wastewater were measured, and PMMoV was quantified. Spatial and temporal variability of PMMoV was observed throughout the study period. PMMoV concentration was significantly higher during dry weather conditions. Multiple linear regression analysis demonstrates that the number and type of physico-chemical parameters that drive PMMoV variability are site-specific, but overall BOD and alkalinity were the most important predictors. Differences in PMMoV concentration for a single WWTP between two different laboratory methods, along with a weak correlation between pellet mass and TSS using one method may indicate that differences in sample concentration and subjective subsampling bias could alter viral recovery and introduce variability to the data.

}, keywords = {Environmental Monitoring, Ontario, Tobamovirus, Waste Disposal, Fluid, Wastewater}, issn = {1879-1026}, doi = {10.1016/j.scitotenv.2024.172917}, author = {Goitom, Eyerusalem and Ariano, Sarah and Gilbride, Kim and Yang, Minqing Ivy and Edwards, Elizabeth A and Peng, Hui and Dannah, Nora and Farahbakhsh, Farnaz and Hataley, Eden and Sarvi, Hooman and Sun, Jianxian and Waseem, Hassan and Oswald, Claire} } @article {92, title = {Hydroxylated 2-Ethylhexyl tetrabromobenzoate isomers in house dust and their agonistic potencies with several nuclear receptors.}, journal = {Environ Pollut}, volume = {227}, year = {2017}, month = {2017 Aug}, pages = {578-586}, abstract = {

In the current study, by combining ultra-high resolution (UHR) MS spectra, MS spectra, and derivatization, three hydroxylated isomers of 2-ethylhexyl tetrabromobenzoate (OH-TBB) were identified in Firemaster 550 and BZ-54 technical products. Also, a new LC-UHRMS method, using atmospheric pressure chemical ionization (APCI), was developed for simultaneous analysis of OH-TBB, TBB, hydroxylated bis(2-ethylhexyl)-tetrabromophthalate (OH-TBPH) and TBPH in 23 samples of dust collected from houses in Saskatoon, SK, Canada. OH-TBBs were detected in 91\% of samples, with a geometric mean concentration of 0.21\ ng/g, which was slightly less than those of OH-TBPH (0.35\ ng/g). TBB was detected in 100\% of samples of dust with a geometric mean concentration of 992\ ng/g. Significant (p\ \<\ 0.001) log-linear relationships between concentrations of OH-TBBs, TBB, or OH-TBPHs and TBPH in dust support the hypothesis of a common source of these compounds. OH-TBBs were found to be strong agonists of peroxisome proliferator-activated receptor gamma (PPARĪ³) and weaker agonists of the estrogen receptor (ER), but no agonistic potencies was observed with the androgen receptor (AR). Occurrence of OH-TBBs in technical products and house dust, together with their relatively strong PPARĪ³ potencies, indicated their potential risk to health of humans.

}, keywords = {Air Pollution, Indoor, Bromobenzoates, Canada, Dust, Environmental Monitoring, Flame Retardants, Halogenated Diphenyl Ethers, Humans}, issn = {1873-6424}, doi = {10.1016/j.envpol.2017.04.094}, author = {Peng, Hui and Sun, Jianxian and Saunders, David M V and Codling, Garry and Wiseman, Steve and Jones, Paul D and Giesy, John P} } @article {103, title = {Untargeted Screening and Distribution of Organo-Bromine Compounds in Sediments of Lake Michigan.}, journal = {Environ Sci Technol}, volume = {50}, year = {2016}, month = {2016 Jan 05}, pages = {321-30}, abstract = {

Previously unreported natural and synthetic organo-bromine compounds (NSOBCs) have been found to contribute more than 99\% of total organic bromine (TOB) in environmental matrices. We recently developed a novel untargeted method (data-independent precursor isolation and characteristic fragment, DIPIC-Frag) and identified \~{}2000 NSOBCs in two sediments from Lake Michigan. In this study, this method was used to investigate the distributions of these NSOBCs in 23 surficial samples and 24 segments of a sediment core from Lake Michigan. NSOBCs were detected in all 23 surficial samples and exhibited 10- to 100-fold variations in peak abundance among locations. The pattern of distributions of NSOBCs was correlated with depth of the water column (r(2) = 0.61, p \< 0.001). Hierarchical cluster analysis showed that sediments in close proximity exhibited similar profiles of NSOBCs. Distributions of NSOBCs in 24 segments of a sediment core dated from 1766 to 2008 were investigated, and samples from similar depths exhibited similar profiles of NSOBCs. NSOBCs were grouped into four clusters (soft-cluster analysis) with different temporal trends of abundances. 515 and 768 of the NSOBCs were grouped into cluster 1 and cluster 3 with increasing temporal trends, especially since 1950, indicating that abundances of these compounds might have been affected by human activities.

}, keywords = {Bromine Compounds, Environmental Monitoring, Geologic Sediments, Halogenated Diphenyl Ethers, Hydrocarbons, Brominated, Lakes, Michigan, Water Pollutants, Chemical}, issn = {1520-5851}, doi = {10.1021/acs.est.5b04709}, author = {Peng, Hui and Chen, Chunli and Cantin, Jenna and Saunders, David M V and Sun, Jianxian and Tang, Song and Codling, Garry and Hecker, Markus and Wiseman, Steve and Jones, Paul D and Li, An and Rockne, Karl J and Sturchio, Neil C and Giesy, John P} } @article {112, title = {Isomer-specific accumulation of perfluorooctanesulfonate from (N-ethyl perfluorooctanesulfonamido)ethanol-based phosphate diester in Japanese Medaka (Oryzias latipes).}, journal = {Environ Sci Technol}, volume = {48}, year = {2014}, month = {2014 Jan 21}, pages = {1058-66}, abstract = {

While (N-ethyl perfluorooctanesulfonamido)ethanol (FOSE) -based phosphate diester (diSPAP) has been proposed as a candidate precursor of perfluorooctanesulfonate (PFOS), its potential biotransformation to PFOS has not been verified. Metabolism of diSPAP was investigated in Japanese medaka ( Oryzias latipes ) after exposure in water for 10 days, followed by 10 days of depuration. Branched isomers of diSPAP (B-diSPAP) were preferentially enriched in medaka exposed to diSPAP, with the proportion of branched isomers (BF) ranging from 0.56 to 0.80, which was significantly greater than that in the water to which the medaka were exposed (0.36) (p \< 0.001). This enrichment was due primarily to preferential uptake of B-diSPAP. PFOS together with perfluorooctanesulfonamide (PFOSA), N-ethyl perfluorooctanesulfonamide (NEtFOSA), 2-(perfluorooctanesulfonamido)acetic acid (FOSAA), NEtFOSAA, FOSE, and NEtFOSE were detected in medaka exposed to diSPAP, which indicated the potential for biotransformation of diSPAP to PFOS via multiple intermediates. Due to preferential metabolism of branched isomers, FOSAA and PFOSA exhibited greater BF values (\>0.5) than those of NEtFOSA, NEtFOSAA, and NEtFOSE (\<0.2). Such preferential metabolism of branched isomers along the primary pathway of metabolism and preferential accumulation of B-diSPAP led to enrichment of branched PFOS (B-PFOS) in medaka. Enrichment of B-PFOS was greater for 3-, 4-, and 5-perfluoromethyl PFOS (P3MPFOS, P4MPFOS, and P5MPFOS), for which values of BF were 0.58 {\textpm} 0.07, 0.62 {\textpm} 0.06, and 0.61 {\textpm} 0.05 (day 6), respectively; these values are 5.8-, 7.8-, and 6.4-fold greater than those of technical PFOS. This work provides evidence on the isomer-specific accumulation of PFOS from diSPAP and will be helpful to track indirect sources of PFOS in the future.

}, keywords = {Alkanesulfonic Acids, Animals, Biotransformation, Chromatography, High Pressure Liquid, Environmental Monitoring, Esters, Fluorocarbons, Gas Chromatography-Mass Spectrometry, Half-Life, Hydrocarbons, Fluorinated, Isomerism, Kinetics, Metabolic Networks and Pathways, Organophosphorus Compounds, Oryzias, Phosphates, Reference Standards, Sulfonamides}, issn = {1520-5851}, doi = {10.1021/es404867w}, author = {Peng, Hui and Zhang, Shiyi and Sun, Jianxian and Zhang, Zhong and Giesy, John P and Hu, Jianying} } @article {111, title = {Trophic transfer of dechloranes in the marine food web of Liaodong Bay, north China.}, journal = {Environ Sci Technol}, volume = {48}, year = {2014}, month = {2014 May 20}, pages = {5458-66}, abstract = {

Dechloranes are of particular concern because of their ubiquity in environmental matrices, but little is known about their trophic transfer in aquatic food web. This study investigated the trophic transfer of seven dechloranes in a marine food web from Liaodong Bay, China. Dechloranes were determined in sediments and 15 marine species including benthic invertebrates, fish and gulls collected from Liaodong Bay. Biomagnification factors (BMFTL) of dechloranes in black-headed gulls were calculated to be 6.4, 1.7, 0.45, 0.36, 0.14, and 0.11 for mirex, Dechlorane 602 (Dec 602), Dechlorane 603 (Dec 603), antiundecachloropentacyclooctadecadiene (anti-Cl11DP), syn-dechlorane plus (syn-DP), and anti-DP. Significantly positive relationships were found between lipid equivalent concentrations of mirex, Dec 602, and anti-Cl11DP and trophic levels, and the trophic magnification factors (TMFs) were 13, 3.7, and 5.6, respectively, indicating that these compounds undergo trophic magnification in the aquatic food web. Lipid equivalent concentrations of Dec 603 and DP isomers did not exhibit a statistically significant correlation with trophic levels. The relatively low trophic magnification potentials of Dec 603 and DP isomers were possibly due to their extreme hydrophobicity (logKOW: 11.2-11.3) and subsequent low bioavailabilities compared with mirex (7.0), Dec 602 (8.1) and anti-Cl11DP. The results provided important information for understanding the ecological risk of dechloranes.

}, keywords = {Animals, Aquatic Organisms, Bays, Charadriiformes, China, Environmental Monitoring, Fishes, Food Chain, Geologic Sediments, Hydrocarbons, Chlorinated, Invertebrates, Ontario, Regression Analysis, Water Pollutants, Chemical}, issn = {1520-5851}, doi = {10.1021/es500229y}, author = {Peng, Hui and Wan, Yi and Zhang, Kun and Sun, Jianxian and Hu, Jianying} }