I've read about dangers to our hearts from air pollution and traffic exhaust.  How serious concern is this?
D000397:Air Pollution / Q000009:adverse effects*; D006321:Heart; D006331:Heart Diseases / Q000209:etiology*; D006801:Humans; D052638:Particulate Matter / Q000009:adverse effects*; D012307:Risk Factors; D001335:Vehicle Emissions
D052638:Particulate Matter; D001335:Vehicle Emissions