Quincy, M.E. - Season 7 Episode 15 To Clear the Air
Overview: An old man at a hospital for respiratory disorders drops dead after going for a walk during a smog alert. Quincy's autopsy reveals lungs that had some kind of inflammation, caused by the pollutants being pumped into the air by the oil refineries near the sanatorium. Refineries that are meant to cut back their emissions during a smog alert!