AsianScientist (Nov. 14, 2017) – A team of researchers at China’s Tsinghua University have demonstrated the success of China’s measures to reduce air pollution. They published their findings in the journal Environmental Research Letters.
Air pollution in China, especially in mega-metropolitan areas, is a matter of concern due to its impact on public health. Exposure to minute particles in the air with diameter less than 2.5 μm (PM2.5) can cause adverse health effects, including cardiovascular and respiratory morbidity and mortality. Outdoor PM2.5 exposure contributed to approximately 1.22 million deaths in China in 2013.
In this study, scientists used satellite-derived aerosol optical depth measurements, ground based observations and air quality simulations to examine the levels of PM2.5 and its adverse health impacts across China. They found that the action plan by the Chinese government to improve air quality, which includes promoting end-of-pipe control measures, limiting coal use in small combustion devices and retiring old vehicles, has led to a 21 percent reduction of population-weighted mean PM2.5 concentration in just two years.
“The Chinese government has made well-publicised moves to improve air quality and reduce pollution across the whole country through its Air Pollution Prevention and Control Action Plan. Our study marks the first estimates of the impact of this stringent action plan on pollution levels and mortality rates from 2013 to 2015,” said Mr. Zheng Yixuan of Tsinghua university who is the first author of the study.
As a result of improved air quality, the researchers estimated that the premature mortality related to PM2.5 pollution has been reduced by nine percent. The smaller health benefits compared to reduction in PM2.5 concentration is due to the non-linear relationship between pollution and mortality in current exposure-response functions.
“It should be noted that the exposure-response functions used in this study are primarily developed by epidemiological studies in developed countries, and subject to uncertainties. More direct evidence from local studies could help us to improve the estimates,” Zhang explained.
PM2.5 concentrations in polluted Chinese provinces are still at the high concentration end, where marginal mortality reductions are relatively small. Therefore, to improve air quality and achieve larger public health benefits in these regions, the government must continue to enforce clean air actions so that public health improves further, said the researchers.
“China is now putting tremendous efforts into mitigating PM2.5 levels in several heavily polluted provinces, such as Beijing, Tianjin, and Hebei (BTH region),” said senior author Professor Zhang Qiang of Tsinghua University. “With the strict control measures, it is most likely China can achieve its goal set in the action plan, i.e., reducing PM2.5 concentration by 25 percent in the BTH region by the end of 2017.”
He added that the mortality burdens induced by air pollution are still severe in China, hence China’s government should continue to focus on reducing PM2.5 across the country.
The article can be found at: Zheng et al. (2017) Air Quality Improvements and Health Benefits from China’s Clean Air Action Since 2013.
Source: IOP Publishing; Photo: Shutterstock.
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