After monitoring levels of fine particulates in the air while riding Los Angeles Metro Red Line (below ground) and Gold Line (aboveground light rail) trains, and on Southern California freeways, a University of Southern California professor concludes that, while the Red Line’s air is a bit dirtier than the Gold Line’s (and that of an average spot in metropolitan L.A.), the freeway air has “five to 10 times higher” concentrations of particulates than a typical urban site. More...
