Short-term exposure to sulfur dioxide and the risk of childhood hand, foot, and mouth disease during different seasons in Hefei, China

Background: Sulfur dioxide (SO2) is an important component of air pollution, adversely impacting human health worldwide. This study aimed to examine the association between short-term exposure to SO2 and childhood hand, foot, and mouth disease (HFMD) in Hefei, China. Methods: A Poisson generalized additive model (CAM) combining the time-series regression analyses was used to fit the 502-HFMD association. The effect of SO2 was estimated using the single-day lag models (lag, lag1, lag2) and the moving average lag models (lag01, lag02) We also conducted stratified analyses by season, ages (0-4 years old, 5-14 years old), gender (male, female), childcare patterns (scattered children, kindergarten children) and residence areas (urban, rural). Two-pollutant models were adopted to test the robustness of the results. Results: There was a statistically significant association between SO2 and the risk of childhood HFMD. For total cases, the relative risk (RR) at lag0 was 1.038 (95% confidence interval (CI): 1.018-1.057) in whole-period and 1.088 (95% CI: 1.059-1.118) in cold season. During cold season, we observed significant associations between SO2 and HFMD among all subgroups except for children aged 5-14 years old and the adverse effects occurred on lag, lagl, lag01, lag02. However, in hot season, SO2 were significant- only for females (lag01 with RR 1.054; 95%Cl = 1.007-1.101) and scattered children (lag01 with RR 1.054; 9.5%Cl 1.007-1.101). In general, females and scattered children appeared to be more vulnerable to SO2. Conclusions: This study suggests a significant association between SO2 and HFMD. especially during cold season. Compared with males and kindergarten children, females and scattered children are at higher risk of developing HFMD. (C) 2018 Elsevier B.V. All tights reserved.