@article {298, title = {Enantioselectivity in Metabolism and Toxicity of 6PPD-Quinone in Salmonids}, journal = {Environmental Science and Technology}, volume = {59}, year = {2025}, author = {Li, R and Barrett, H and Nair, P and Wang, MH and Tomlin, H and Atkinson, JB and Krogh, E and Xie, LN and Peng, H} } @article {225, title = {Building the Environmental Chemical-Protein Interaction Network (eCPIN): An Exposome-Wide Strategy for Bioactive Chemical Contaminant Identification}, journal = {Environmental Science and Technology}, year = {2023}, chapter = {in press}, author = {Gong, YF and Yang, DW and Barrett, H and Yang, DW and Peng, H} } @article {236, title = {Effects of Triclosan on the Development of Antimicrobial Resistance in the Environment: A Review}, journal = {Current Pollution Report}, year = {2023}, author = {Zhang, CZ and Liu, SH and Feng, HD and Barrett, H and Karunaratne, SHP and Zhang, Y and Yang, M} } @article {175, title = {A Roadmap to the Structure-Related Metabolism Pathways of Per- and Polyfluoroalkyl Substances in the Early Life Stages of Zebrafish (Danio rerio)}, journal = {Environ. Health. Perspect.}, volume = {129}, year = {2021}, abstract = {

BACKGROUND: Thousands of per- and polyfluoroalkyl substances (PFAS) with diverse structures have been detected in the ambient environment. Apart from a few well studied PFAS, the structure-related toxicokinetics of a broader set of PFAS remain unclear.

OBJECTIVES: To understand the toxicokinetics of PFAS, we attempted to characterize the metabolism pathways of 74 structurally diverse PFAS samples from the U.S. EPA{\textquoteright}s PFAS screening library.

METHODS: Using the early life stages of zebrafish (Danio rerio) as a model, we determined the bioconcentration factors and phenotypic toxicities of 74 PFAS. Then, we applied High-Resolution Mass Spectrometry based non-targeted analysis to identify metabolites of PFAS in zebrafish larvae after five days of exposure, by incorporating retention time and mass spectra. In vitro enzymatic activity experiments with human recombinant liver carboxylesterase (hCES1) were employed to validate the structure-related hydrolysis of 11 selected PFASs.

RESULTS: Our findings identified five structural categories of PFAS prone to metabolism. The metabolism pathways of PFAS are highly related to their structures as exemplified by fluorotelomer alcohols that the predominance of β-oxidation or taurine conjugation pathways were primarily determined by the number of hydrocarbons. Hydrolysis is a major metabolism pathway for diverse PFAS and perfluoroalkyl carboxamides showed the highest in vivo hydrolysis rates, followed by carboxyesters and sulfonamides. The hydrolysis of PFAS was verified with recombinant hCES1, with strong substrate preferences towards perfluoroalkyl carboxamides.

CONCLUSIONS:We suggest that the roadmap of the structure-related metabolism pathways of PFAS established in this study would provide a starting point to inform the potential health risks of other PFAS.

}, author = {Han, JJ and Gu, W and Barrett, H and Yang, DW and Tang, S and Sun, JX and Liu, JB and Krause, HM and Houck, KA and Peng, H} }