China's weather authorities issued an orange alert on Saturday as heavy smog covered central and eastern regions of the country, according to dpa. Jiangsu, Zhejiang, Anhui and Henan provinces have suffered smog for six consecutive days, the Xinhua news agency said, while other central and eastern regions have already experienced three to five days of smog. China's four-tier warning system for extreme weather includes blue, yellow, orange and red alerts. Shanghai has been plagued by high levels of air pollution for several days after air masses carried industrial emissions from neighbouring Jiangsu and Zhejiang provinces. Shanghai authorities on Friday halted all construction work and ordered children indoors as the financial hub suffered one of its worst bouts of air pollution. Officials also reduced bus service by one-third and cancelled some flights to and from Shanghai airport. The city's concentration of harmful fine particles in the air reached 602 micrograms per cubic metre Friday, 24 times higher than the level considered tolerable by the World Health Organization. By mid-day Saturday, the figure had fallen to an "unhealthy" 182. Beijing's index had risen to a "severely polluted" 303. Medical experts warned that the levels of air pollution could increase the risk of stroke and heart disease, as well as cause respiratory problems, birth defects and cancer. Meteorologists said the weather was partly responsible for the lingering air masses, adding that the current bout of air pollution would likely continue until the end of the week.
