02/24/2026
When people talk about "experiments" at Pruitt-Igoe, they are usually referring to one of two things: the broader sociological experiment of high-rise public housing, or a specific, literal military experiment involving chemical spraying that came to light decades later.
1. The Secret Aerosol Study (The "Zinc Cadmium Sulfide" Experiment)
This is the most controversial "experiment" associated with the site. During the 1950s and 60s, at the height of the Cold War, the U.S. Army used Pruitt-Igoe as a testing ground for chemical warfare defenses.
• The Method: The Army set up blowers on the roofs of the buildings and on the backs of station wagons. They sprayed a chemical compound called Zinc Cadmium Sulfide (mixed with fluorescent particles) into the air.
• The Goal: The military wanted to track how biological or chemical agents would disperse in an urban environment. They chose Pruitt-Igoe because its dense, high-rise layout mimicked Soviet cities like Moscow.
• The Deception: Residents were told the government was testing a "smoke screen" to protect the city from Russian aerial reconnaissance.
• The Fallout: Decades later, researchers and survivors raised alarms about high cancer rates in the area. While the Army maintained the chemical was non-toxic, cadmium is a known carcinogen.