The words "Made in China" are synonymous with inexpensive electronics and housewares purchased in the United States. But a consequence of Americans' buying habits is air pollution that's also made in China, researchers say.
Much of the air pollution traveling across the Pacific Ocean to the West Coast of the United States is caused by China's manufacturing of such goods for export to the United States and Europe, a new study asserts.
For Los Angeles, this air pollution from the production of consumer items (such as cellphones and televisions) causes at least one extra day a year of smog that exceeds federal ozone limits, according to the researchers. On some days, as much as one-quarter of the sulfate pollution on the U.S. West Coast is linked to Chinese manufacturing of export products, the investigators said.
"We've outsourced our manufacturing and much of our pollution, but some of it is blowing back across the Pacific to haunt us," study co-author Steve Davis, an Earth system scientist at the University of California, Irvine, said in a university news release.
"Given the complaints about how Chinese pollution is corrupting other countries' air, this paper shows that there may be plenty of blame to go around," he noted.
Most U.S. air pollution stems from domestic sources such as vehicles and refineries, the researchers said. However, powerful global winds called the "westerlies" can carry airborne pollutants from China across the Pacific Ocean, particularly during the spring.
Black carbon air pollution from China is a particular problem. It isn't easily washed out of the atmosphere by rain, so it can travel long distances. Black carbon has been linked to various health problems, including asthma, emphysema, heart and lung disease, and cancer.
These findings could be used to more effectively negotiate clean-air treaties between nations, according to the authors of the study, published Jan. 20 in the journal Proceedings of the National Academy of Sciences.
China's rapidly increasing industrial activity and its poor pollution controls have led to often intense international debates. But blame for the pollution isn't China's alone, the study authors noted.
"When you buy a product at Wal-Mart, it has to be manufactured somewhere. The product doesn't contain the pollution, but creating it caused the pollution," Davis said.
He and his colleagues concluded: "International cooperation to reduce transboundary transport of air pollution must confront the question of who is responsible for emissions in one country during production of goods to support consumption in another."
