Associations between short-term ambient ozone exposure and cause-specific mortality in the rural and urban areas of Jiangsu, China

Abstract

BACKGROUND AND AIM: Ambient ozone pollution has been worsening in China. However, current understanding on the acute health effects of ozone is limited to urban areas, partly due to the paucity of air pollutant measurements in rural areas. We here applied modeled ambient ozone exposure covering both rural and urban areas to evaluate the associations between short-term ozone exposure and cause-specific mortality in Jiangsu Province, China, 2015-2018. METHODS: We divided a total of 86 Jiangsu counties equally into urban and rural based on the median value of the percentage of urban residents across Jiangsu counties. We estimate the county-specific daily maximum 8-hour average ozone concentration using a recently developed spatiotemporal machine learning model in China at a resolution of 0.1° × 0.1°. We first estimated county-specific effect of ozone using generalized linear models, adjusting for long-term and seasonal trend, day of week, temperature, and humidity. We then pooled the overall urban and rural area estimates by random-effects meta-analysis. RESULTS:Short-term ambient ozone exposure was associated with mortality of non-accidental cause in rural areas (percentage increase in mortality per 10 μg/m³, 0.45%; 95% confidence interval [CI], 0.29%-0.61%) and urban areas (0.36%; 95% CI, 0.23%-0.49%). The association was significant for mortality caused by respiratory disease or cardiovascular disease in both areas. Our results remain similar after additional adjustments for PM₂.₅ and alternative methods of controlling temperature. CONCLUSIONS:Short-term ambient ozone exposure was associated with increased risk of cause-specific mortality, and the effect size of ozone in rural areas was similar to that in urban areas in Jiangsu Province. This finding suggests that residents in rural areas also suffer adverse health effects from short-term ozone exposure. KEYWORDS: Air pollution, Ozone, Short-term exposure, Mortality