Association between ambient air pollution and hospital admission for epilepsy in Eastern China

BACKGROUND We aimed to study the short-term association between air pollutants and hospitalization for epilepsy in 47 hospitals from 10 cities in eastern China. METHOD We identified hospital epilepsy admissions in 2014 and 2015. A conditional Poisson regression model was used to examine the association between air pollutants and hospital admission, with temperature and relative humidity adjusted using the natural spline (ns) function. Pollutants included sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter (PM). The association was stratified by sex, age, and geographic region in single-pollutant and two-pollutant models. RESULTS An interquartile (IQR) increase of NO2 and CO on the concurrent day is correlated with an increased admission of 2.0% (0.5%, 3.6%) and 1.1% (0.1%, 2.1%), respectively. The association is stronger in children (≤18 years) and in northern China, but did not vary with sex. A positive association was also observed on the previous day for CO [1.5%, 95% confidence interval (CI): 0.3%, 2.6%], NO2 (2.5%, 95% CI: 0.6%, 4.3%), and PM2.5 (1.32%, 95% CI: 0.16%, 2.48%). Moving average concentration of 7 days for all pollutants was associated with decreased admission (CO: -1.29%, NO2: -0.4.69%, SO2:-2.12%, PM2.5:-0.98%, PM10:-1.70%). CONCLUSION Exposures to NO2 and CO on concurrent days, and PM2.5 on the previous day, are associated with increased epilepsy hospitalization, whereas cumulative exposure appeared protective.