Association between short-term exposure to ambient PM1 and PM2.5 and forced vital capacity in Chinese children and adolescents

This study aims to examine the association between short-term exposure to ambient PM1, PM1-2.5, and PM2.5 and forced vital capacity (FVC). Population data were obtained from a school-based cross-sectional survey in Shandong in 2014. Distributed lag non-linear models were used to examine the association between exposure to PM1, PM1-2.5, and PM2.5 and FVC at the day of FVC measurement and the previous 6 days (lag 0 to 6 days). A total of 35,334 students aged 9 to 18 years were included in the study, and the mean exposure concentrations of ambient PM1, PM1-2.5, and PM2.5 for them were 47.4 (standard deviation [SD] = 21.3) mu g/m(3), 32.8 (SD = 32.2) mu g/m(3), and 80.1 (SD = 47.7) mu g/m(3), respectively. An inter-quartile range (IQR, 24 mu g/m(3)) increment in exposure to PM1 was significantly associated with a lower FVC at lag 0 and lag 1 day (beta = - 80 mL, 95% CI = - 119, - 42, and beta = - 37 mL, 95% CI = - 59, - 16, respectively), and an IQR (54 mu g/m(3)) increment in exposure to PM2.5 was significantly associated with a lower FVC at lag 0 and lag 1 day (beta = - 57 mL, 95% CI = - 89, - 18, and beta = - 34 mL, 95% CI = - 56, - 12, respectively) after adjustment for gender, age, body mass index category, residence, month of the survey, intake of eggs, intake of milk, physical activity, and screen time. No significant associations were observed for PM1-2.5. The inverse associations of PM1 and PM2.5 with FVC were larger in males, younger children, those overweight or obese, and those with insufficient physical activity levels. Short-term exposure to ambient PM1 and PM2.5 was associated with decreased FVC, and PM1 may be the primary fraction of PM2.5 causing the adverse pulmonary effects. Our findings emphasize the need to address ambient PM, especially PM1, pollution for affecting pulmonary health in children and adolescents.