The heavy smog that has blanketed parts of China is clearing in places.<br /><br /> A pollution index that measures the average concentration of small breathable particles, known as PM2.5, dropped to just over 100 micrograms per cubic metre in Beijing early on Monday.<br /><br /> The index had topped 500 on Sunday evening.<br /><br /> According to the World Health Organisation, the safe recommended level of PM2.5 is 100 micrograms per cubic metre.<br /><br /> <br /><br /><br /> China starts 2017 engulfed by smog, issues pollution alerts. https://t.co/VRGr9KhuTb— The Associated Press (@AP) January 2, 2017<br /> <br /><br /> <br /><br /><br /> Is the smog gone for good?<br /><br /> Possibly not.<br /><br /> Forecasters say it is likely to be only a brief respite. <br /><br /> More smog is expected to return to the wintry north within 24 hours.<br /><br /> Beijing and the nearby city of Tianjin will be affected once more from Tuesday. <br /><br /> The smog is expected to persist until Thursday in Hebei, the heavily-industrialised area surrounding the capital. <br /><br /> Henan and Shandong provinces will also be affected.<br /><br /> <br /><br /><br /> Beijing will extend orange alert for heavy air pollution for another 3 days as #smog continues in the city https://t.co/YX1jC3LbAF pic.twitter.com/v6opFyCyls— China Xinhua News (@XHNews) January 2, 2017<br /> <br /><br /> <br /><br /><br /> What the Chinese government is doing<br /><br /> Late on Sunday, the Ministry of Environmental Protection said 62 northern cities had issued yellow, orange or red alerts.<br /><br /> Chinese state television reported some highways to Beijing and Tianjin were re-opened as motorists headed home at the end of the long weekend.<br /><br /> However, 20 remained closed in Shandon province, as the heavy smog persisted.<br /><br /> Alerts since mid-December<br /><br /> The authorities have been issuing smog alerts across the north since mid-December.<br /><br /> Hundreds of factories have been ordered to scale back production <br />or even close outright.<br /><br /> There have been restrictions on motorists to cut emissions.<br /><br /> <br /><br /><br /> Unauthorized resumption of production found in environment inspections in #smog-hit China https://t.co/jziWex0xi1 https://t.co/ZcwlcPvG4p pic.twitter.com/M73YaqM5rs— China Xinhua News (@XHNews) January 2, 2017<br /> <br /><br /> <br /><br /><br /> Pollution alerts “common”<br /><br /> Pollution alerts are common in northern China, esoecially during winter when coal-fuelled energy demand soars.<br /><br /> Commentators say China has struggled to tackle the problem effectively, after decades of breakneck economic growth.<br /><br /> Much of this has been based on heavy industry and the coal-fired power sector.<br />
