School Buses Cited as Among Worst Polluters

California’s school buses are among the nation’s most polluting, says a study by the Union of Concerned Scientists.

Nearly half of the state’s 24,190 buses don’t have to meet air-quality standards because they are more than 10 years old, according to the Cambridge, Mass.-based environmental advocacy group.

California’s average school bus discharges the same amount of particulates in a year as 170 cars, the report says.

California Air Resources Board spokesman Jerry Martin disagreed with the conclusions, saying the state has allocated $66 million to improve or replace buses over the past two years.