Associations of Particulate Matter Sizes and Chemical Constituents with Blood Lipids: A Panel Study in Guangzhou, China

Existing evidence is scarce concerning the various effects of different PM sizes and chemical constituents on blood lipids. A panel study that involved 88 healthy college students with five repeated measurements (440 blood samples in total) was performed. We measured mass concentrations of particulate matter with diameters <= 2.5 mu m (PM2.5), <= 1.0 mu m (PM1.0), and <= 0.5 mu m (PM0.5) as well as number concentrations of particulate matter with diameters <= 0.2 mu m (PN0.2) and <= 0.1 mu m (PN0.1). We applied linear mixed-effect models to assess the associations between short-term exposure to different PM size fractions and PM2.5 constituents and seven lipid metrics. We found significant associations of greater concentrations of PM in different size fractions within 5 days before blood collection with lower high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A (ApoA1) levels, higher apolipoprotein B (ApoB) levels, and lower ApoA1/ApoB ratios. Among the PM2.5 constituents, we observed that higher concentrations of tin and lead were significantly associated with decreased HDL-C levels, and higher concentrations of nickel were associated with higher HDL-C levels. Our results suggest that short-term exposure to PM in different sizes was deleteriously associated with blood lipids. Some constituents, especially metals, might be the major contributors to the detrimental effects.

Automated summary

This study found a significant association between short-term exposure to different sizes of particulate matter and blood lipids, especially with the major contributions from metal constituents. Metal particles like tin, lead, and nickel were observed to have detrimental effects on different lipid metrics, suggesting the importance of considering PM constituents in assessing the impact on cardiovascular health.