Yao Yuan/EPA PHOTO/SIPA PRESS
Coal may be the biggest culprit. China has tens of thousands of small mines that pay scant attention to environmental concerns or safety, and thousands of miners die underground each year.
Such neglect helps keep costs down, so most of China's electricity comes from power plants that burn high-sulfur coal. Worse, few have effective emission controls, a big contributor to the acid rain that falls on one-third of the country.