Where There's Smoke

A visitor to China may well notice the country's smog problem as the plane descends. Smog levels in large cities such as Beijing and Shanghai frequently dwarf those of other metropolitan centres. Then there's the cigarette smoke. China, the world's most populous country, claims about one-third of the world's smokers — at least 300 million people — who collectively puff 1.7 trillion cigarettes a year. In rural areas, cigarette smoke permeates buses, shops and even doctors' offices.Beyond cigarette smoke and outdoor air pollution, hundreds of millions of Chinese people breathe unclean air while working in factories and on industrial-scale farms or while cooking at wood-burning stoves inside their homes.These airborne toxicants — many of which are by-products of China's economic boom — are risk factors for chronic obstructive pulmonary disease (COPD), an incurable respiratory disorder that can cause severe breathing difficulties. And they have public-health officials worldwide worried about a coming epidemic. “We're just seeing the tip of the iceberg on COPD in China,” says Don Sin, a respiratory medicine specialist at the University of British Columbia in Vancouver, Canada, who researches COPD. “In 30 years, [the number of cases] is going to explode.”A large-scale study in China put the prevalence of COPD in 2004 at roughly 8% in people who are 40 or older¹, in line with rates in the United Kingdom and the United States. But because China has seen soaring rates of industrialization and tobacco use over the past few decades, and because COPD symptoms aren't typically noticed until after age 50, public-health experts say the future is bleak. According to Sin, projections based on current trends and World Health Organization estimates show that by 2030, COPD will kill 3 million Chinese people a year — a million more than die annually now.Read more at...Nature, September 2012.