New satellite measurements show how polluted Los Angeles´ air really is
(WorldNews Environment)

Scientists who scanned the skies above dozens of U.S. cities have made a surprising discovery about the smog that´s suspended over Los Angeles: one of its key ingredients isn´t disappearing as fast as it once did. The finding may help explain why the once-steady improvements in air quality have come close to stalling out here even though nitrogen oxide emissions have continued to decline. It also suggests that the particular chemistry of L.A.`s air may complicate future cleanup efforts. `That´s certainly part of why we´re in a moment in Los Angeles where it´s harder to get the air cleaner,` said Ronald Cohen, an atmospheric chemist at UC Berkeley who reported the findings in the journal...