Tens of thousands of California schoolchildren ride aging school buses that emit harmful pollutants, an analysis of state data shows.

Unlike many states, California does not require bus owners to take buses off the road after a set number of years. As a result, California has some of the oldest buses in the nation.

The emissions from older school buses are harmful to both children and air quality for the broader community.

Children riding in conventional diesel school buses are exposed to more air pollution than those riding in cleaner natural gas or low emission diesel buses, according to a 2003 study conducted by the California Air Resources Board.

Buses manufactured before 1990 can pollute as much as six times more than new buses, according to the Environmental Protection Agency. There are about 3,000 buses in the state built in the 1980s and earlier, according to a California Watch analysis of data maintained by the California Highway Patrol.

via Aging, polluting school buses remain on Calif. roads | California Watch.