How Air Pollution Damages Your Skin Barrier (PM2.5, Urban Smog & Daily Protection) — USA Guide Air pollution is no longer just a lung health concern. In major U.S. cities — from Los Angeles and San Diego to New York, Chicago, and Houston — pollution has become one of the most underestimated causes of premature skin … Continue reading How Air Pollution Damages Your Skin Barrier (PM2.5, Urban Smog & Daily Protection) — USA Guide