TAIPEI ( TheStreet) -- Not long ago a friend from Beijing emailed me a list of gripes about daily life in China's ever-challenging capital. But it ended with good news for the masses as well as for multinationals who sell to them."Air pollution, food safety, water pollution," my friend beefed. Heard it before. But then: "More and more people, including me, have started to install air and water purifiers in their homes." That comment, though not entirely new, still hit me like mountain spring water. It means that common Chinese can solve some of the numerous health and habitability problems they face daily but usually can't control -- and that thousands of publicly traded appliance sellers can breezily sell millions of purifiers. You can't exterminate people in a packed subway car to give yourself space or make your local petty official quit stealing money just by asking. But you can buy appliances to purify air and water at home. seriously polluted. The World Bank warns the blight will cost China 5.8% of its GDP, most of that because of health care. Airborne particulates known as PM2.5 are the most talked about offender. In Beijing, Shanghai, Guangzhou and Xi'an their levels exceed World Health Organization guidelines, meaning increased risks of cardiovascular disease, cancer and premature death, Greenpeace says in a statement on its Web site. "China's economy has skyrocketed, but at a price," Greenpeace says. "Power plants, factories and heavy industries are all belching out black, dirty air at the cost of our health and our environment." But 35% of China's economy comes now from domestic consumption, not just factory exports. Chinese officials want to raise that percentage so the country pollutes less and depends less on bumpy export demand from Western markets. Rising household incomes are already on the government's side. The 2011 average annual income of $4,940 grew by 13% in the first three quarters of last year, according to the World Bank and Chinese state-run media.