Though the pollution comes from China, the U.S. still bears part of the responsibility. That’s because about a fifth of China’s air pollution comes from the manufacture of goods for export to other countries, including the U.S., China’s second-largest trading partner. The study found that manufacturing for the export sector contributed to 36 percent of China’s sulfur dioxide emissions, 27 percent of its nitrogen oxides, 22 percent of its carbon monoxide and 17 percent of its black carbon — a pollutant linked to cancer, emphysema and asthma.
“When you buy a product at Wal-Mart, it has to be manufactured somewhere,” Steve Davis, co-author of the study and University of California at Irvine scientist told the Washington Post. “The product doesn’t contain the pollution, but creating it caused the pollution.”