Air pollution synergy of PM2.5 and O3 Synergy on Mortality | Prof Luigi Fontana

This BMJ study revealed notable interactive connections between PM2.5 and O3. The mortality estimates were more pronounced when individuals were exposed to higher levels of both pollutants, as shown in detailed analyses. Additionally, the synergy index indicated substantial synergistic interactions. Interestingly, we noticed diverse interactive patterns affecting different mortality measures depending on the region and season. These results underscore the importance of implementing synchronized strategies to control these two air pollutants effectively. Authors employed two established methods to investigate the interplay of PM2.5 and O3 in 372 cities worldwide. These findings consistently demonstrated positive interactions between these pollutants. For instance, the rise in total mortality linked to a 10 μg/m3 increase in PM2.5 was %, %, and % with low, medium, and high O3 exposure, revealing a clear and significant positive interaction. Furthermore, the authors utilized the synergy index to quantify these combined effects. The synergy indices were , , and for total, cardiovascular, and respiratory mortality, respectively. These values indicate a synergistic interaction between PM2.5 and O3, surpassing the combined impact of their individual associations. The implications for policy arising from this study are significant. Firstly, the research presents compelling evidence of the synergistic interplay between PM2.5 and O3 in their impact on mortality in numerous cities worldwide. This implies that prior risk assessments, which focused solely on individual associations of air pollutants, may have underestimated their true combined effect on disease burden. Regarding air quality regulation, it is imperative to implement strategies that comprehensively address both PM2.5 and O3. This could involve targeted measures like end-of-pipe controls or shifts in energy sources. It’s noteworthy that regional and seasonal factors may influence the interaction between PM2.5 and O3 in relation to various mortality outcomes, with more pronounced effects observed in high latitude regions and during colder seasons. In essence, our findings highlight a larger disease burden linked to PM2.5 and O3 exposure than what can be attributed to their individual contributions. This underscores the necessity for coordinated efforts in controlling these air pollutants in the future.