Chinese government announced a war on air pollution in early 2013. The government declared stringent polices to regulate the emissions of particulate matter, which is known as PM 2.5. Over the course of five years, China’s fast approach towards restricting the number of vehicles on the road resulted in lowering the PM 2.5 concentrations nearly about 40 percent. However, rising ozone pollution caused by reducing PM 2.5 concentrations completely baffled the researchers of John A. Paulson School of Engineering and Applied Sciences (SEAS).
Rapid Reduction of PM 2.5 Leaves More Radicals to Produce Ozone
Ozone is formed through chemical reactions which includes the oxidation of volatile organic compounds (VOCs). Such reaction generates chemical radicals that trigger VOCs to produce ozone in the presence of sunlight. The researchers from SEAS found out that particulate matter sucks up the radicals needed to generate ozone pollution.
The larger cities in China are witnessing huge ozone pollution due to rapid reduction of PM 2.5. The steps taken towards rapidly lowering PM 2.5 concentrations leave more radicals available to produce ozone, consequently causing ozone pollution. According to Daniel Jacob, a family professor of Atmospheric Chemistry, China is the first nations to experience such a dramatic level of ozone pollution as no other countries acted on minimizing particulate matter emissions.
Researchers of NUIST are planning to put extra efforts to reduce VOC and nitrogen oxides emissions in order to stem the tide of ozone pollution.