Long-term exposure to ozone and diabetes incidence: A longitudinal cohort study in China

Ozone (O3) has become a prominent air pollutant problem as other pollutants concentrations have decreased obviously since China published Air Pollution Action Plan Pollution Prevention Action Plan in 2013. Few studies examined the association between O3 and diabetes especially in developing countries. This study was designed to investigate the above topic in China.We conducted a prospective cohort study based on a nationwide survey of 13,548 adults from China Health and Retirement Longitudinal Study. City-level exposure to ozone for each participant was matched through ChinaHighO3 dataset. Time-varying cox proportional hazard regression model was applied to determine the association. Stratification analyses were conducted to explore potential effect modification.The annual mean concentration of O3 was 86.6 μg/m3. A 10 μg/m3 increase in 1-year average O3 concentration was associated with 5.7% (95% CI: 1.004-1.114) relative increment in hazards ratio of diabetes incidence in the fully adjusted model. Results stayed stable when controlling for physical activity, PM2.5 and mean temperature.Our findings provided initial support for a positive and robust association between long-term exposure to O3 and diabetes incidence in a developing country. More scientific and social attention should be attached to the ozone-induced risks of diabetes occurrence.