A constant part of talks about air pollution has been ambient fine particulate matter (or PM), the world’s leading environmental health risk factor. Research has shown that only at 2.5 micrometres or smaller, these particles are small enough to be inhaled, causing respiratory and cardiovascular issues.
Now, a new study has shown that global population-weighted PM2.5 exposure has steadily decreased from 2011 to 2019, allowing the world to breathe better.
Over the years, many nations have adopted different initiatives to reduce PM2.5 particles, which are mainly produced by traditional energy sources such as burning fossil fuels or wood. To understand the effectiveness of these mitigation efforts, researchers examined PM2.5 data from 1998 to 2019, a press statement by Washington University in St. Louis explains.
The findings, published recently in the journal Nature Communications, showed that global, population-weighted PM2.5 exposure, related to pollution levels and population size, increased from 1998 to a peak in 2011, then decreased steadily from 2011 to 2019, mainly because of exposure reduction in China and slower growth in other regions.
Before this study, there was a knowledge gap regarding “quantitative local/regional contributions to global population exposure to PM2.5 and its changes" Chi Li, the study’s first author, explains in the statement. "We developed a new regional decomposition approach that jointly considered pollution level and population size, and from that, we depicted the first-ever time series of regional contributions to global PM2.5 air pollution," Li added.
The strict air quality management in China, which has been more evident since 2013 has been the biggest contributor (90%) to the global reversal, the researchers said in the statement. The benefits of the reduction include 1.1. million fewer premature deaths in China between 2011 and 2019 and overall improved health.
Although this is good news, the researchers emphasise that further mitigation efforts are crucial to reduce PM2.5 exposure. Currently, population ageing and growth are the main challenges in alleviating PM2.5 health impacts, they said.
Millions of people are still dying prematurely worldwide because of exposure to PM2.5, highlighting the need for continued reduction of PM2.5 exposure. Monitoring regions that are highly populated but poorly monitored such as South Asia and the Middle East is important for the mitigation efforts, the researchers said in the press statement.