Study: Western U.S. smog originates across the ocean in Asia

Pollution is a global problem, and that reality is highlighted by a new study indicating smog in western U.S. states originates from Asian countries across the ocean. The movement of this pollution from Asia to the U.S. is curbing the latter country's emission-reduction efforts. In some cases, pollution coming primarily from China and India is causing 65-percent of the ozone …