Beijing’s air quality target for 2017 is more than double the acceptable standard set by the World Health Organisation , the mayor announced on Saturday in the wake of weeks of hazardous air pollution in the Chinese capital. “We will work hard to keep PM2.5 at an annual average of around 60 micrograms per cubic meter,” Beijing mayor Cai Qi said during his delivery of the city’s annual work report at the opening of the Beijing People’s Congress on Saturday.