Short-Term effects of ambient ozone on the risk of conjunctivitis outpatient visits: a time-series analysis in Pudong New Area, Shanghai.

To date, the relationship between conjunctivitis and air pollutants has been widely concerned, but the conclusions are not very unified. This study aims to explore the short-term effects of ambient ozone (O3) on the conjunctivitis outpatient visits in Pudong New Area, Shanghai. A quasi-Poisson model combined with the distributed lag nonlinear model (DLNM) was performed to study the short-term effects of O3 on the risk of outpatient visits for conjunctivitis, after controlling the effects of temperature, relative humidity and wind speed. Taking the median concentration of O3 as a reference, the moderate high O3 (75th percentile) showed the largest effect estimates for single and cumulative lag effects at lag 4 (RR 1.013, 95% confidence interval [CI] 1.006-1.019) and lag 0-10 (RR 1.075, 95%CI 1.025-1.128), respectively. Our study suggested that the moderate high O3 increased the chances of conjunctivitis outpatient visits and had an evident lag effect.