Say what you will about Los Angeles—that it's a hellpit of plastic-enhanced heathens teetering on the brink of seismic annihilation, for example—but give the city this: it has America's worst air.

America sent its manufacturing to China, but the pollution is "coming back to haunt us," according to a new study. The jobs and economic growth remain on the other side of the Pacific. This seems like a pretty bad deal, overall.