Concentration-dependent health effects of air pollution in controlled human exposures

We examined PM concentration-responses after controlled human air pollution exposures to examine exposure-response markers, assess effect modifiers, and identify potential effect thresholds.METHODS: We reviewed primary research from published controlled human exposure studies where responses were reported at multiple target PM concentrations or summarized per unit change in PM to identify concentration-dependent effects.RESULTS: Of the 191 publications identified through PubMed and supplementary searches, 31 were eligible. Eligible studies collectively represented four pollutant models: concentrated ambient particles, engineered carbon nanoparticles, diesel exhaust, and woodsmoke. We identified concentration-dependent effects on oxidative stress markers, inflammation, and cardiovascular function that overlapped across different pollutants. Metabolic syndrome and glutathione s-transferase mu 1 genotype were identified as potential effect modifiers.DISCUSSION: Improved understanding of concentration-response relationships is integral to biomonitoring and mitigation of health effects through impact assessment and policy. Although we identified potential concentration-response markers, thresholds, and modifiers, our conclusions on these relationships were limited by a dearth of eligible publications, considerable variability in methodology, and inconsistent reporting standards between studies. More research is required to validate these observations. We recommend that future stud...

Source: Environment International - February 17, 2021 Category: Environmental Health Authors: Juma Orach Christopher F Rider Christopher Carlsten Source Type: research