Effect of PM exposure on adhesion molecules and systemic nitric oxide in healthy adults: The role of metals, PAHs, and oxidative potential.

Since there is limited evidence on the impact of PM content on cardiovascular biomarkers, we conducted a cross-sectional study on 89 healthy adults from October 12 to November 21, 2021. We measured daily PM in two distinct regions during different time windows: a high-traffic urban area and an industrial suburb. The concentrations of metals, PAHs, and oxidative potential (OP) were determined using ICP-MS, GC-MS, and dithiothreitol (DTT), respectively. Systemic biomarkers, including NO, sICAM-1, sVCAM-1, MDA, and CRP, were quantified in each subject simultaneously. A generalized linear model was used to examine the association between PM toxicity and each health endpoint. Our findings indicated that daily PM concentrations exceeded the WHO-recommended level by approximately sevenfold. We found that PM exposure was associated with adverse cardiovascular outcomes. Moreover, exposure to PM mass, total PAHs, and certain trace metals (Ni, Fe, V, As, and Pb) resulted in a decline in serum NO levels. At lag 3, exposure to PM mass resulted in a significant decrease in NO levels [1.32% (95% CI: -2.27, -0.12)] and total PAHs [2.05% (95% CI: -3.93, -0.12)]. In contrast, OP exhibited a mild correlation with NO level increases. Positive associations were observed between PM and its chemical constituents (PAHs, As, Cu, OP) and adhesion molecules at different lag times. An increase of 0.16 ppb in PAH concentrations at an interquartile range was associated with a 4.74% decline (95% CI, -7.80, -0.55) in the sVCAM-1 level. However, our study did not reveal any significant trend between pollutants and other biomarkers (sICAM-1, MDA, and CRP). Consequently, our findings suggest that different PM chemical compositions exhibit diverse behavior in biological responses.