Billowing across the Pacific Ocean from China and landing on the western shore of the United States are significant quantities of toxic air pollutants, including sulfur dioxide, nitrogen oxides, carbon monoxide, and black carbon. Ironically, a great deal of that air pollution is caused by the production of goods inside China for export to the United States.

A paper that was published in the Proceedings of the National Academy of Sciences on Monday is the first time researchers quantified how much pollution was actually reaching the West Coast of the United States. Unfortunately, the disturbing findings indicate that although a decrease in U.S. manufacturing has improved air quality in eastern portions of the U.S., the West Coast has been harmed by China’s exported pollutants.

Los Angeles, which already suffers from copious amounts of air pollutants, endures at least one more day each year that exceeds federal ozone standards because of air toxins emitted by the Chinese industrial complex. Moreover, as much as a quarter of sulfate pollution on the West Coast can be linked to the manufacture of Chinese exports.

The Report demonstrates that U.S. demand for cheap imports such as cell phones, televisions, and appliances has backfired to some extent. “It’s sort of a boomerang effect,” explained system scientist at UC Irvine and co-author of the study. “We’ve outsourced our manufacturing and much of our pollution, but some of it is blowing back across the Pacific to haunt us.”

Not surprisingly, popular unrest has surfaced in China in response to the ever-increasing domestic air pollution and accompanying smog. “I did not even dare to cross the street,” said Zhang Xiaofeng, a 24-year old bulldozer driver who suffers from eye pain and chronic coughing because of the smog. “I waited and waited at the intersection and looked again and again, but I couldn’t see if any cars were coming. Even the traffic lights were invisible.”