St. Louis used as test site for toxic fog experiment, U.S. officials confirm

The U.S. government has admitted to secretly spraying a carcinogen-laced fog over St. Louis for years during the Cold War, exposing thousands of residents without their knowledge.

The U.S. government has now admitted to carrying out a mysterious fog experiment over St. Louis, spraying a chemical that contained a carcinogen on thousands of unsuspecting residents.

Officials specifically chose St. Louis because its layout resembled Moscow’s, making it a Cold… pic.twitter.com/S2gOR8f0D8

— Shadow of Ezra (@ShadowofEzra) August 31, 2025

The U.S. government has now admitted to carrying out a mysterious fog experiment over St. Louis, spraying a chemical that contained a carcinogen on thousands of unsuspecting residents.

Officials specifically chose St. Louis because its layout resembled Moscow’s, making it a Cold War testing ground.

The spraying went on for years, while people unknowingly lived under the toxic haze.

Decades ago, U.S. government agencies acknowledged they had conducted Cold War-era aerosol experiments over St. Louis and several other American cities.

At the time, officials claimed the tests were aimed at developing protective smoke screens to shield the public in the event of an attack. However, subsequent disclosures revealed the operations were linked to a biological weapons program, in which potentially harmful chemicals and microorganisms were secretly dispersed over unwitting citizens.