In Harbin,fine particulate matter (PM2.5) reached levels of 1,000 micrograms per cubic metre in some parts of the city,readings 40 times the level that the World Health Organization considers ideal for human health. Reducing visibility to less than 50 metres,the smog forced schools to cancel classes,most flights and close highways. China,the worlds largest consumer of coal,is also the worlds leader in carbon emissions.
In October,officials in Beijing announced emergency measures in a bid to tackle the problem of air pollution,including mandatory factory closures and bans on cars entering the city on days when pollution levels are particularly high. The citys Heavy Air Pollution Contingency Plan stipulates that when there is serious pollution for three consecutive days, a warning system comprising blue,yellow,orange and red the most serious alerts will be activated. Schools will then have to stop classes,while 80 per cent of government-owned cars will be taken off the roads.
In June,Singapore had its worst environmental crisis in more than a decade when skyscrapers in the city were shrouded by thick smog as raging fires in neigbouring Indionesias Sumatra Island pushed air pollution levels to an all-time high. Singapores Pollution Standard Index (PSI) peaked at 401 a point where simply breathing becomes potentially fatal for the sick or elderly. Schools were closed,deliveries came to a halt,and protective masks were flying off hospital shelves. Hundreds of schools across Malaysia were also shut down.
Between 2011 and 2012,4,460 people died from air pollution in Tehran. The cloud of yellow smog enveloping Tehran has now become an annual event. Officials urged residents to stay indoors and likened going outside to suicide. The city was shut down for five days in an attempt to keep cars off the road. The Iranian capital is surrounded by mountains that trap the toxic air. Because of strict restrictions imposed by the US in 2010,Iran has struggled to find fuel for its cars,so people began to mix their own bathtub gas which has severely contributed to the rising levels of air pollution.
When a severe cold spell hit London in early December 1952,Londoners did what they usually did in such a situation; they burned more coal to heat up their homes. Since the smoke from the coal burning in homes,plus all of Londons usual factory emissions,had been prevented from escaping into the atmosphere by an inversion,the fog and smoke combined into a rolling,thick layer of smog. In the five days the smog had covered London,over 4,000 people died. In the following weeks,8,000 more died from exposure to what has become known as the Great Smog of 1952.