Nancy Kirk and Camelle Sison explain fine particle pollution, where it comes from and how PM2.5 can pose a risk to peoples' health when it's found in the atmosphere. This student-created video was produced by KC Stanfield, Eduardo Garcia, and Jennifer Rocha.
This video is part of an explainer series for "What's in the Air?" a collaboration between the San Diego State University School of Journalism and Media Studies and inewsource. Aerial San Diego photo by Sam Hodgson