Association between exposure to ambient particulate matter and high sensitivity C-reactive protein: A nationwide study in South Korea, 2015-2018

Existing evidence suggests that exposure to ambient particulate matter (PM) causes various adverse health outcomes through systemic inflammation. We explored the association between PM exposure and high- sensitivity C-reactive protein (hs-CRP) levels in a Korean population. This cross-sectional study included a representative sample of 21,154 Korean individuals, linked to modeled air quality data from 2015 to 2018. Concentrations of PM10 and PM 2.5 were estimated for 1-week (short-term), 2-month, 4-month, 6-month (medium-term), and 1-year (long-term) moving averages before the survey date for each participant. The association between log-transformed hs-CRP levels and PM exposure was assessed using linear regression. The effect sizes were expressed as percent changes with 95% confidence intervals (CIs). The percent change (95% CI) in hs-CRP levels per a 10-mu m/m3 increase in PM10, according to moving averages, was 0.47 (-1.13, 2.10) for 1-week, 4.87 (2.50, 7.29) for 2-month, 8.21 (4.89, 11.64) for 4-month, 11.26 (6.81, 15.89) for 6-month, and 7.15 (2.54, 11.98) for 1-year. The percent change (95% CI) in hs-CRP levels per a 10-mu m/m3 increase in PM2.5, according to moving averages, was 0.66 (-2.38, 3.79) for 1-week, 7.51 (2.86, 12.36) for 2-month, 14.26 (8.23, 20.62) for 4-month, 20.29 (12.42, 28.70) for 6-month, and 17.76 (8.51, 27.79) for 1-year. The relationship between PM exposure and hs-CRP levels remained independent even after adjusting for sociodemographic characteristics and other co- pollutants. Exposure to PM10 and PM2.5, particularly over longer periods, showed positive association with hsCRP levels in Korean adults. These findings highlight the necessity for policy efforts aimed at enhancing air quality and mitigating the health impacts of PM exposure.