Short-Term Effects of Particle Sizes and Constituents on Blood Biomarkers among Healthy Young Adults in Guangzhou, China.

Evidence of the effects of various particle sizes and constituents on blood biomarkers is limited. We performed a panel study with five repeated measurements in 88 healthy college students in Guangzhou, China between December 2017 and January 2018. Mass concentrations of particles with aerodynamic diameters ≤ 2.5 μm (PM), PM, and PM and number concentrations of particles with aerodynamic diameters ≤ 200 nm (PN) and PN were measured. We used linear mixed-effect models to explore the associations of size-fractionated particulate matter and PM constituents with five blood biomarkers 0-5 days prior to blood collection. We found that an interquartile range (45.9 μg/m) increase in PM concentration was significantly associated with increments of 16.6, 3.4, 12.3, and 8.8% in C-reactive protein (CRP), monocyte chemoattractant protein-1 (MCP-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and endothelin-1(ET-1) at a 5-day lag, respectively. Similar estimates were observed for PM, PM, PN, and PN. For PM constituents, consistent positive associations were observed between F and sVCAM-1 and CRP and between NH and MCP-1, and negative associations were found between Na and MCP-1 and ET-1, between Cl and MCP-1, and between Mg and sVCAM-1. Our results suggested that both particle size and constituent exposure are significantly associated with circulating biomarkers among healthy Chinese adults. Particularly, PN at a 5-day lag and F and NH are the most associated with these blood biomarkers.