China's smog hits new highs (and lows)

China's capital has been gripped for days by the worst air pollution on record, prompting the country to shut down factories and pull government cars off the road. Even the typically staid state media has provided widespread and critical coverage of the issue after measurements taken over the weekend exceeded the highest levels on the Air Quality Index.

On Saturday, a Twitter feed from the U.S. Embassy rated the air in central Beijing at a whopping 755 on an air quality index of 0 to 500, reported the New York Times. AQI, which the EPA uses to measure pollution, puts levels between 151 and 200 as unhealthy and anything over 301 as hazardous.

The Beijing government reported later that night levels of particulate matter with a diameter of 2.5 micrometers, known as PM 2.5, that exceeded 900 micrograms per cubic meter. That's similar levels found during London's killer smog, which killed up to 12,000 people in 1952, the NYT noted.

PM 2.5 is a particle that's small in size, but packs a punch. As pollution, it can spread over a large surface area and is known to carry toxic heavy metals, chemicals and organic pollutants. The EPA regulates PM2.5, recently setting the health standard at 12 micrograms per cubic meter.

As industry in China has boomed and more of its citizens begin to drive cars, air pollution has become an increasingly stubborn and expensive issue that has caused some Chinese cities to take action. For instance, Guangzhou said in September 2012 it would halve the number of new cars on its streets using license plate auctions and lotteries.

Air pollution has already exacted huge costs to the country's economy. An MIT study released last year determined air pollution cost China's economy $112 billion in 2005, nearly a five-fold increase from 1975. Exposure to PM 2.5 caused an estimated 8,572 premature deaths in Shanghai, Guangzhou, Xi’an and Beijing in 2012 and led to total economic losses of $1.08 billion in those cities, according to a joint study by Greenpeace East Asia and Peking University's School of Public Health.

Another famously polluted city, Mexico City, has tried--with some success--to adopt urban sustainability projects, such as installing vertical gardens that function as both art and oxygenators as well as instituting policies to curb traffic, promote lower emission vehicles and promote public transportation.

Photos: Greenpeace East Asia

This post was originally published on Smartplanet.com