Air pollution from factories and power plants in booming Asian cities is blowing across the Pacific to the West Coast of North America, posing threats to human health and wildlife far from the pollution’s original sources, according to a report published last week in the journal Science. Report coauthor Kenneth Wilkening of the University of Northern British Columbia said, “With increasing industrialization around the world, everybody is upwind or downwind of everybody else.” The pollution, including ozone, mercury, and persistent organic pollutants, takes only 5 to ten days to reach North America from Asia, and is particularly problematic in the winter and spring. As East Asian economies continue to expand, some fear the pollution crossing the Pacific may make it difficult for West Coast states to meet U.S. clean air goals.

Grist thanks its sponsors. Become one.