Los Angeles air pollution – and its infamous eye sting – have declined due to California’s strict vehicle emission controls, scientists have said.

Despite a three-fold rise in the number of vehicles on southern California roads since 1960, air pollution there has decreased, a study found.

That includes peroxyacetyl nitrate, known to irritate the eyes, the US government study found.

The study “confirms” vehicle regulations worked, its author said.

“LA’s air has lost a lot of its ‘sting,'” said lead author Ilana Pollack of the National Oceanic and Atmospheric Association’s research centre at the University of Colorado Boulder.

She said the study “confirms that California’s policies to control emissions have worked as intended”.

In addition, ozone pollution has improved, although Los Angeles remains the worst city in America for ozone pollution, according to the American Lung Association.

continue reading BBC News – Los Angeles air pollution drops after tailpipe laws.