@article {288, title = {Fast autoxidation of unsaturated lipid films on indoor surfaces.}, journal = {Nat Commun}, volume = {16}, year = {2025}, month = {2025 Feb 12}, pages = {1557}, abstract = {

Organic films containing unsaturated lipids are widespread, yet their oxidation pathways with associated impacts on contaminant lifetimes and human exposure remain poorly explored under indoor environmental conditions. This study demonstrates that UVA radiation and radical exposure drive rapid autoxidation of thin films of methyl linolenate (ML) and canola oil (which contains polyunsaturated triglycerides), primarily producing organic hydroperoxides. For ML films this fast chemistry occurs at the same rate under entirely dark, genuine indoor conditions as it does when the films are exposed to significantly higher OH radicals in a flow reactor. Both OH and organic radicals are detected within the oxidized films, propagating fast autoxidation in dark indoor environments with minimal sensitivity to the radical initiation rate. When mixed into the films, bisphenol A is hydroxylated, illustrating potential transformation pathways for toxic organic contaminants. This study uncovers insights into lipid autoxidation processes under environmental conditions and underscores their potential health impacts.

}, keywords = {Benzhydryl Compounds, Bisphenol A Compounds, Fatty Acids, Monounsaturated, Humans, Hydrogen Peroxide, Linoleic Acids, Oxidation-Reduction, Phenols, Rapeseed Oil, Surface Properties, Ultraviolet Rays}, issn = {2041-1723}, doi = {10.1038/s41467-025-56802-0}, author = {Wang, Xinke and Fahy, William D and Xie, Linna and Peng, Hui and Abbatt, Jonathan P D} } @article {291, title = {New Sources of Very Persistent and Very Mobile (vPvM) Substances: A Case Study of the Fluorinated Herbicide Pyroxasulfone.}, journal = {Environ Sci Technol}, year = {2025}, month = {2025 Apr 03}, abstract = {

With the increasing use of fluorinated agrochemicals, more fluorinated compounds enter into the environment. Pyroxasulfone (PYS), a broad-spectrum herbicide containing an aromatic CF (Ar-CF), is expected to grow significantly in application. Although several transformation products (TPs) of PYS have been reported, their distribution and contribution to transformation processes remain largely unknown. This study combined laboratory simulations and a field study. In soil incubation and soil surface photolysis experiments, (5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl)-1-pyrazol-4-yl)methanesulfonic acid (TFPSA) was identified as the main TP of PYS in soil, accounting for over 90\% of all TPs. Field study results showed that PYS and TFPSA were the main species in soil (6.48 {\textpm} 1.82 and 1.54 {\textpm} 0.90 ng g wet weight) and corn plants (2.55 {\textpm} 2.61 and 31.1 {\textpm} 39.6 ng g dry weight in roots) before harvest. Surface water photolysis experiments showed that TFPSA and TP were the major TPs of PYS and no significant photodegradation of TFPSA was observed. Persistent (P) and mobile (M) property assessment indicated TFPSA, TP, and other Ar-CF containing TPs of various fluorinated agrochemicals could be potential very P and very M (vPvM) substances. More attention should be paid to Ar-CF containing agrochemicals and their TPs.

}, issn = {1520-5851}, doi = {10.1021/acs.est.4c13346}, author = {Hou, Xingwang and Gauthier, Jeremy R and Nair, Pranav and Fahy, William D and Peng, Hui and Mabury, Scott A} } @article {273, title = {Hydroxyl radical oxidation of chemical contaminants on indoor surfaces and dust.}, journal = {Proc Natl Acad Sci U S A}, volume = {121}, year = {2024}, month = {2024 Nov 05}, pages = {e2414762121}, abstract = {

Humans are widely exposed to semivolatile organic contaminants in indoor environments. Many contaminants have long lifetimes following partitioning to the large surface reservoirs present indoors, which leads to long exposure times to gas-phase oxidants and multiphase chemistry. Studies have shown selective multiphase oxidation of organics on indoor surfaces, but the presence of hydroxyl radicals with nonselective reactivity and evidence of multiphase OH radical reactivity toward common indoor contaminants indicates that there may be additional unknown transformation chemistry indoors. We screened genuine indoor samples for 60 OH radical oxidation products of the common plasticizer and endocrine-disrupting contaminant bis(2-ethylhexyl) phthalate (DEHP) identified in laboratory experiments using nontargeted high-resolution mass spectrometry. At least 30 and 10 of these products are observed in indoor dust and DEHP films exposed to ambient indoor conditions, respectively, indicating that multiphase OH reactions occur indoors. Using the PROTEX model and a multimedia indoor chemical fate model, we demonstrate that these products have long indoor lifetimes and cause a higher potential for human exposure than DEHP. Some of these products are more active endocrine disruptors than DEHP itself, but most have unknown toxicities. Coexposure to all oxidation products will likely have an additive effect, leading to higher human health risks from indoor organic contaminants than previously thought. Due to the nonselective reactivity of OH radicals, it is likely that most indoor contaminants follow similar chemistry, and further study is needed to understand the prevalence and human health implications of such multiphase chemistry.

}, issn = {1091-6490}, doi = {10.1073/pnas.2414762121}, author = {Fahy, William D and Gong, Yufeng and Wang, Shenghong and Zhang, Zhizhen and Li, Li and Peng, Hui and Abbatt, Jonathan P D} } @article {260, title = {Light Exposure of Wood Smoke Aerosol: Connecting Optical Properties, Oxidation, Radical Formation, and Chemical Composition}, journal = {ACS ES\&T Air}, volume = {1}, year = {2024}, author = {Liu-Kang, Carolyn and Sokolova, Anna and Gong, Yufeng and Fahy, William D and Peng, Hui and Abbatt, Jonathan PD} }