Inter-continental variability in the relationship of oxidative potential and cytotoxicity with PM<sub>2.5</sub> mass.

Salana, Sudheer; Yu, Haoran; Dai, Zhuying; Subramanian, P S Ganesh; Puthussery, Joseph V; Wang, Yixiang; Singh, Ajit; Pope, Francis D et al. · Nat Commun · 2024

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Abstract

Most fine ambient particulate matter (PM<sub>2.5</sub>)-based epidemiological models use globalized concentration-response (CR) functions assuming that the toxicity of PM<sub>2.5</sub> is solely mass-dependent without considering its chemical composition. Although oxidative potential (OP) has emerged as an alternate metric of PM<sub>2.5</sub> toxicity, the association between PM<sub>2.5</sub> mass and OP on a large spatial extent has not been investigated. In this study, we evaluate this relationship using 385 PM<sub>2.5</sub> samples collected from 14 different sites across 4 different continents and using 5 different OP (and cytotoxicity) endpoints. Our results show that the relationship between PM<sub>2.5</sub> mass vs. OP (and cytotoxicity) is largely non-linear due to significant differences in the intrinsic toxicity, resulting from a spatially heterogeneous chemical composition of PM<sub>2.5</sub>. These results emphasize the need to develop localized CR functions incorporating other measures of PM<sub>2.5</sub> properties (e.g., OP) to better predict the PM<sub>2.5</sub>-attributed health burdens.

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