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) μg/m³, 32.8 (SD = 32.2) μg/m³, and 80.1 (SD = 47.7) μg/m³, respectively. An inter-quartile range (IQR, 24 μg/m³) increment in exposure to PM₁ 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/m³) increment in exposure to PM₂.₅ 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 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.