(Yicai Global) Aug. 29 -- A report by international environmental organization Clean Air Asia says air quality improved in Chinese cities in 2015, but the air pollution picture is still not upbeat. Pollution caused by particulate matter 2.5 (PM2.5) has not been effectively addressed, and ozone pollution is emerging.
According to 'China Air 2016: Air Pollution Prevention and Control Progress in Chinese Cities', in 2015, the number of non-attainment days in 161 Chinese cities averaged 99, and the yearly average concentrations of PM2.5, PM10, SO2 and NO2 in 74 major cities declined compared with 2014.
PM2.5 remains the most pressing problem for most Chinese cities. In 74 major cities, including Beijing, Shanghai and Guangzhou, the average PM2.5 concentrations were still higher than the grade-two national standard, with average readings 1.5 times higher than the national standard (35 micrograms /cubic meter).
Ozone pollution first emerged in 2014 and worsened in 2015. The yearly concentration in the 74 major cities continued to increase by 3.4 percent. In Beijing, Tianjin and Hebei in 2015, days with ozone as the primary pollutant outnumbered all other pollutants excluding only PM2.5. Ozone was the only pollutant that worsened in the Yangtze River Delta.
Thus far, many cities such as Beijing, Shanghai, Tianjin, Shenzhen and Xi'an have taken measures to curb ozone pollution, including open-air barbecuing, restaurant exhaust fumes and auto emissions.