DIAMOND BAR, Calif. (AP) — Southern California air regulators have approved new restrictions on area oil refineries that could remove tons of smog-forming pollutants from the air.

The board of the South Coast Air Quality Management District adopted rule changes Friday requiring emissions limits on oxides of nitrogen.

Those are the gases produced by combustion that contribute to ozone smog.

The AQMD says the new rules could reduce those gases by about eight tons a day over the next 14 years.

California has some of the nation's dirtiest air, and some of the worst air quality is near refineries clustered near low-income, heavily minority neighborhoods.