Short-term effects of ambient air pollution on emergency department visits for urolithiasis: A time-series study in Wuhan, China

BACKGROUND: Previous studies have explored the correlation between short-term exposure to air pollution and urinary system diseases, but lack of evidence on the correlation between air pollution and urolithiasis. METHODS: Daily data of emergency department visits (EDVs), concentrations of six air pollutants (SO(2), NO(2), PM(2.5), PM(10), CO, and O(3)) and meteorological variables were collected in Wuhan, China, from 2016 to 2018. And a time-series study was conducted to investigate short-term effects of air pollutants on urolithiasis EDVs. In addition, stratified analyses by season, age and gender were also conducted. RESULTS: A total of 7,483 urolithiasis EDVs were included during the study period. A 10-μg/m(3) increase of SO(2), NO(2), PM(2.5), CO, PM(10), and O(3) corresponded to 15.02% (95% confidence interval [CI]: 1.69%, 30.11%), 1.96% (95% CI: 0.19%, 3.76%), 1.09% (95% CI:−0.24%, 2.43%), 0.14% (95% CI: 0.02%, 0.26%), 0.72% (95% CI: 0.02%, 1.43%), and 1.17% (95% CI: 0.40%, 1.94%) increases in daily urolithiasis EDVs. Significant positive correlations were observed between SO(2), NO(2), CO, and O(3) and urolithiasis EDVs. The correlations were mainly among females (especially PM(2.5) and CO) and younger people (especially SO(2), NO(2), and PM(10)) but the effect of CO was more obvious in elders. Furthermore, the effects of SO(2) and CO were stronger in warm seasons, while the effects of NO(2) were stronger in cool seasons. CONCLUSION: Our time-series study indicates that short-term exposure to air pollution (especially SO(2), NO(2), CO, and O(3)) was positively correlated with EDVs for urolithiasis in Wuhan, China, and the effects varied by season, age and gender.