Ozone Pollution Worsens in North China

Concentrations of hazardous ground-level ozone have worsened in northern China despite country-wide efforts to tackle air pollution, according to a study published by Peking University on Tuesday.  Stringent winter restrictions on industry, transportation and coal consumption enabled smog-prone northern Chinese regions to meet politically crucial air quality targets for the 2013-2017 period, the Economic Times reported.  But while concentrations of hazardous airborne particles known as PM2.5 fell, average daytime ozone levels jumped sharply, according to a study of pollution data in 33 northern cities by Peking University's Guanghua School of Management and the Center for Statistical Science.  Cuts in other forms of pollution are believed to have contributed to the rise.  "Regional declines in the amount of PM2.5 and PM10 have reduced the volume of floating particles and increased the strength of the sunlight required to produce ozone," the paper said. A study by Chinese researchers published last year identified ozone as a growing health risk that had caused a rise in deaths from strokes and heart disease.