Coarse Particulate Matter and Markers of Inflammation and Coagulation in the Multi-Ethnic Study of Atherosclerosis (MESA) Population: A Repeat Measures Analysis

Abstract

Background: In contrast to fine particles, less is known of the inflammatory and coagulation impacts of coarse particulate matter (${\mathrm{PM}}_{10-2.5}$, particulate matter with aerodynamic diameter $\le 10\mu m\text{and}>2.5\mu m$). Toxicological research suggests that these pathways might be important processes by which ${\mathrm{PM}}_{10-2.5}$ impacts health, but there are relatively few epidemiological studies due to a lack of a national ${\mathrm{PM}}_{10-2.5}$ monitoring network.

Objectives: We used new spatiotemporal exposure models to examine associations of both 1-y and 1-month average ${\mathrm{PM}}_{10-2.5}$ concentrations with markers of inflammation and coagulation.

Methods: We leveraged data from 7,071 Multi-Ethnic Study of Atherosclerosis and ancillary study participants 45-84 y of age who had repeated plasma measures of inflammatory and coagulation biomarkers. We estimated ${\mathrm{PM}}_{10-2.5}$ at participant addresses 1 y and 1 month before each of up to four exams (2000-2012) using spatiotemporal models that incorporated satellite, regulatory monitoring, and local geographic data and accounted for spatial correlation. We used random effects models to estimate associations with interleukin-6 (IL-6), C-reactive protein (CRP), fibrinogen, and D-dimer, controlling for potential confounders.

Results: Increases in ${\mathrm{PM}}_{10-2.5}$ were not associated with greater levels of inflammation or coagulation. A $10{\text{-}\mu g/m}^3$ increase in annual average ${\mathrm{PM}}_{10-2.5}$ was associated with a 2.5% decrease in CRP [95% confidence interval (CI): $-5.5$, 0.6]. We saw no association between annual average ${\mathrm{PM}}_{10-2.5}$ and the other markers (IL-6: $-0.7\%$, 95% CI: $-2.6$, 1.2; fibrinogen: $-0.3\%$, 95% CI: $-0.9$, 0.3; D-dimer: $-0.2\%$, 95% CI: $-2.6$, 2.4). Associations consistently showed that a $1{0\text{-}\mu g/m}^3$ increase in 1-month average ${\mathrm{PM}}_{10-2.5}$ was associated with reduced inflammation and coagulation, though none were distinguishable from no association (IL-6: $-1.2\%$, 95% CI: $-3.0$, 0.5; CRP: $-2.5\%$, 95% CI: $-5.3$, 0.4; fibrinogen: $-0.4\%$, 95% CI: $-1.0$, 0.1; D-dimer: $-2.0\%$, 95% CI: $-4.3$, 0.3).

Discussion: We found no evidence that ${\mathrm{PM}}_{10-2.5}$ is associated with higher inflammation or coagulation levels. More research is needed to determine whether the inflammation and coagulation pathways are as important in explaining observed ${\mathrm{PM}}_{10-2.5}$ health impacts in humans as they have been shown to be in toxicology studies or whether ${\mathrm{PM}}_{10-2.5}$ might impact human health through alternative biological mechanisms. https://doi.org/10.1289/EHP12972.