Association between short-term exposure to ambient PM₁ and PM_2.5 and forced vital capacity in Chinese children and adolescents.

This study aims to examine the association between short-term exposure to ambient PM <sub>1</sub> , PM <sub>1-2.5</sub> , and PM <sub>2.5</sub> 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 PM <sub>1</sub> , PM <sub>1-2.5</sub> , and PM <sub>2.5</sub> 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 PM <sub>1</sub> , PM <sub>1-2.5</sub> , and PM <sub>2.5</sub> for them were 47.4 (standard deviation [SD] = 21.3) μg/m <sup>3</sup> , 32.8 (SD = 32.2) μg/m <sup>3</sup> , and 80.1 (SD = 47.7) μg/m <sup>3</sup> , respectively. An inter-quartile range (IQR, 24 μg/m <sup>3</sup> ) increment in exposure to PM <sub>1</sub> was significantly associated with a lower FVC at lag 0 and lag 1 day (β = - 80 mL, 95% CI = - 119, - 42, and β = - 37 mL, 95% CI = - 59, - 16, respectively), and an IQR (54 μg/m <sup>3</sup> ) increment in exposure to PM <sub>2.5</sub> was significantly associated with a lower FVC at lag 0 and lag 1 day (β = - 57 mL, 95% CI = - 89, - 18, and β = - 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 PM <sub>1-2.5</sub> . The inverse associations of PM <sub>1</sub> and PM <sub>2.5</sub> with FVC were larger in males, younger children, those overweight or obese, and those with insufficient physical activity levels. Short-term exposure to ambient PM <sub>1</sub> and PM <sub>2.5</sub> was associated with decreased FVC, and PM <sub>1</sub> may be the primary fraction of PM <sub>2.5</sub> causing the adverse pulmonary effects. Our findings emphasize the need to address ambient PM, especially PM <sub>1</sub> , pollution for affecting pulmonary health in children and adolescents