Clearing the Air: The War on Smog

What happens when an entire city can't see across the street, people flood hospitals unable to breathe, and scientists must solve a deadly atmospheric puzzle?

In 1943, mysterious clouds choked Los Angeles. Chemist Arie Haagen-Smit discovered "photochemical smog"—gasoline hydrocarbons reacting with sunlight to create toxic ozone. What followed was a decades-long battle as auto manufacturers conspired to suppress catalytic converter technology they'd invented in the 1950s, delaying solutions for years. The fight sparked America's first Air Pollution Control District, California's groundbreaking emission standards, and ultimately the EPA and Clean Air Act of 1970.

Proof that regulation backed by science and civic pressure can succeed against powerful corporate interests.