Review of studies evaluating respiratory toxicity of aerosols: impact of cell types, chemical composition, and atmospheric processing.

In recent decades, several cell-based and acellular methods have been developed to evaluate ambient particulate matter (PM) toxicity. Although cell-based methods provide a more comprehensive assessment of PM toxicity, their results are difficult to comprehend due to the diversity in cellular endpoints, cell types, and assays and the interference of PM chemical components with some of the assays' techniques. In this review, we attempt to clarify some of these issues.

Inter-continental variability in the relationship of oxidative potential and cytotoxicity with PM mass.

Most fine ambient particulate matter (PM)-based epidemiological models use globalized concentration-response (CR) functions assuming that the toxicity of PM is solely mass-dependent without considering its chemical composition. Although oxidative potential (OP) has emerged as an alternate metric of PM toxicity, the association between PM mass and OP on a large spatial extent has not been investigated. In this study, we evaluate this relationship using 385 PM samples collected from 14 different sites across 4 different continents and using 5 different OP (and cytotoxicity) endpoints.

Effect of Biomass Burning, Diwali Fireworks, and Polluted Fog Events on the Oxidative Potential of Fine Ambient Particulate Matter in Delhi, India.

We investigated the influence of biomass burning (BURN), Diwali fireworks, and fog events on the ambient fine particulate matter (PM) oxidative potential (OP) during the postmonsoon (PMON) and winter season in Delhi, India. The real-time hourly averaged OP (based on a dithiothreitol assay) and PM chemical composition were measured intermittently from October 2019 to January 2020. The peak extrinsic OP (OP: normalized by the volume of air) was observed during the winter fog (WFOG) (5.

Sources of cellular oxidative potential of water-soluble fine ambient particulate matter in the Midwestern United States.

We investigated the spatiotemporal distribution and sources of cellular oxidative potential (OP) in the Midwest US. Weekly samples were collected from three urban [Chicago (IL), Indianapolis (IN), and St. Louis (MO)], one rural [Bondville (IL], and one roadside site [Champaign (IL)] for a year (May 2018 to May 2019), and analyzed for water-soluble cellular OP using a macrophage reactive oxygen species (ROS) assay.