Government officials took the unusual step of closing some of the freeways in Beijing earlier this month, the latest in a series of increasingly frantic efforts to reduce the city's seemingly endemic problems with air pollution so severe that many residents now walk around wearing masks to reduce the amount of soot and smoke they breathe.
They have reason to worry, warns a new study released by the International Agency for Research on Cancer, a research arm of the World Health Organization. The agency has formally declared what many medical experts have long suspected: Air pollution causes lung cancer.
The study points an accusing finger at a variety of sources, including the coal-burning power plants of China, the widespread agricultural operations of California—and the diesel cars and trucks found all over the world.
"The air most people breathe has become polluted with a complicated mixture of cancer-causing substances," said agency department chief Kurt Straif told The Associated Press, warning that air pollution is now considered to create a more serious risk of lung cancer than second-hand cigarette smoke. The agency contends that more than 220,000 people around the world died in 2010 due to cancers arising from air pollution.
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The study follows up on earlier reports that warned about the risk of specific types of air pollution. It contends that pollutants have become so ever-present that in many parts of the world the simple act of breathing puts people at risk for not just lung but possibly other cancers including that of the bladder.
A major concern is the presence of particulates, super-fine particles of soot and other substances that can find their way deep into the lungs. That's been a particular concern for those who oppose the expanded use of diesels.
"People can certainly contribute by doing things like not driving a big diesel car, but this needs much wider policies by national and international authorities," Straif said.
It's not the first time the World Health Organization has taken aim at the diesel engine. It declared diesel exhaust "a known carcinogen" in a June 2012 report. But the WHO decision was somewhat nuanced, suggesting that the problem was more severe in emerging markets than in countries like the U.S.—and particularly in Europe, where diesel is the powertrain option of choice in roughly half of all new vehicles sold each year.
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