To help cut air pollution in the nation’s smoggiest state, California officials announced last week that they will soon begin converting the state government’s entire 10,000-vehicle fleet to low-polluting or non-polluting vehicles. One quarter of the fleet will be made up of gasoline-powered cars that release up to 90 percent fewer pollutants than typical new models, while the other 75 percent of the fleet is already required by federal law to be powered by alternative fuels or electricity. In a separate move intended to crack down on diesel exhaust, the South Coast Air Quality Management District on Friday approved a measure that will require government fleets of heavy-duty trucks in Southern California to switch to cleaner fuels beginning in two years; taxis that serve the L.A. airport will have to make a similar switch. It’s about time — children growing up in Southern California’s smoggiest areas tend to develop lung capacity at a slower rate than those who live in cleaner communities, according to a new study published in the American Journal of Respiratory and Critical Care Medicine.

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