Effect of ambient O on respiratory mortality and synergies with meteorological factors in Shenyang, China.

The impact of O on the respiratory system is a significant global problem. Nevertheless, there is insufficient information about its impact on respiratory disorders in northeast China. In this study, we used a generalized additive model (GAM) to determine the correlation between O concentrations and respiratory deaths based on the daily meteorological data, pollutant concentrations, and respiratory deaths from 2014 to 2016 in Shenyang, a typical city in northeast China. Single and cumulative lag structures and seasonal modification were considered to investigate the link between O exposure and respiratory mortality in Shenyang, northeast China. Synergic effects of O and meteorological factors were also evaluated. Results indicated that there was a significant correlation between O and the number of deaths caused by respiratory diseases on a daily basis, regardless of the time delay between exposure and the occurrence of the deaths. A 10 µg/m rise in O concentration was associated with a 0.85% (95% CI 0.18-1.52%) increase in respiratory death at a lag of 1 day and a 1.43% (95% CI 0.40-2.48%) increase at a cumulative lag of 3 days. Stratified analyses revealed that O had a greater impact on health under warm conditions compared to cold settings. Additionally, O had a more pronounced effect on females than on males. The results for this study could provide some scientific guidance for local environment and health departments.