Fine particles with a diameter of less than 2.5 microns (PM2.5) have captured national headlines when it comes to air pollution, but experts are calling for more attention to ozone, which can also be harmful, the Economic Information Daily reports.
With the arrival of summer, ozone has overtaken PM2.5 as China's top air pollutant, according to a report in July covering 74 major cities by the Ministry of Environmental Protection. The ministry says ozone will continue to worsen air quality until October.
Although the stratospheric ozone layer is far from where people live and reduces the amount of ultraviolet light entering the earth's atmosphere, ground-level ozone can cause harmful effects. Those include damage to tissues in the respiratory tracts of humans, as well as detrimental effects to crops, forests and native plants, according to experts.
A study shows that when ozone levels reach 50 parts per billion, China will lose its winter wheat harvest of 4.13 million tons and soybean yield of 885,000 tons.
Environmental experts say the forming of ozone pollution is even harder to analyze than PM2.5, as it changes with seasons and locations. Meng Xiaoyan, an engineer at the China National Environmental Monitoring Center, says southern Chinese cities suffer higher ozone levels than northern cities.
Wang Yuesi, a researcher at the Institute of Atmospheric Physics (Chinese Academy of Sciences), says ozone worsens air pollution in cities like Beijing, Shanghai and Guangzhou, so it requires a coordinated effort and government support to tackle the issue.
Regional environmental bureaus should join hands with scientific institutes to better identify the causes behind ozone pollution and work out comprehensive strategies.