Association of Short-Term Co-Exposure to Particulate Matter and Ozone with Mortality Risk

Abstract

A complex regional air pollution problem dominated by particulate matter (PM) and ozone (O3) needs drastic attention since the levels of O3 and PM are not decreasing in many parts of the world. Limited evidence is currently available regarding the association between co-exposure to PM and O3 and mortality. A multicounty time-series study was used to investigate the associations of short-term exposure to PM1, PM2.5, PM10, and O3 with daily mortality from different causes, which was based on data obtained from the Mortality Surveillance System managed by the Jiangsu Province Center for Disease Control and Prevention of China and analyzed via overdispersed generalized additive models with random-effects meta-analysis. We investigated the interactions of PM and O3 on daily mortality and calculated the mortality fractions attributable to PM and O3. Our results showed that PM1 is more strongly associated with daily mortality than PM2.5, PM10, and O3, and percent increases in daily all-cause nonaccidental, cardiovascular, and respiratory mortality were 1.37% (95% confidence interval (CI), 1.22–1.52%), 1.44% (95% CI, 1.25–1.63%), and 1.63% (95% CI, 1.25–2.01%), respectively, for a 10 μg/m3 increase in the 2 day average PM1 concentration. We found multiplicative and additive interactions of short-term co-exposure to PM and O3 on daily mortality. The risk of mortality was greatest among those with higher levels of exposure to both PM (especially PM1) and O3. Moreover, excess total and cardiovascular mortality due to PM1 exposure is highest in populations with higher O3 exposure levels. Our results highlight the importance of the collaborative governance of PM and O3, providing a scientific foundation for pertinent standards and regulatory interventions.

Joint Effect of Short-Term Exposure to Fine Particulate Matter and Ozone on Mortality: A Time Series Study in 272 Chinese Cities

“…The synergistic effect of coexposure to high levels of PM 2.5 and O 3 on mortality was more pronounced in men and younger people (<65-year-old) in this study. Previous studies regarding the independent effect of PM 2.5 or O 3 on mortality mostly reported that women and older people are more vulnerable ,− ; therefore, they started to suffer from the hazardous effects of PM 2.5 or O 3 at relatively low pollution levels in this study. By contrast, the hazardous effect of air pollution on men or younger people, who were not sensitive to relatively low air pollution levels, was significantly higher or only significant with coexposure to high levels of PM 2.5 and O 3 .…”

“…It was noteworthy that limited study has explored the interaction between pollutants and mortality with fixed cutoffs of pollutants. One study based on data from one Chinese province found interactions between PM 2.5 and O 3 on mortality with cutoffs of 25 μg/m 3 for PM 2.5 and 100 μg/m 3 for O 3 , respectively . Overall, our results based on data from 272 cities in China added strong evidence to support a synergistic effect of PM 2.5 and O 3 on nonaccidental, cardiovascular, and respiratory mortalities.…”