Mental Floss rounds up eight conspiracies that could be true. (Could be, Mental Floss?)
From 1940 to 1970, America was a giant germ laboratory. The U.S. Army wanted to assess how vulnerable America was to a biological attack, so it spread clouds of microbes and chemicals over populated areas everywhere.
In 1949, the Army Special Operations released bacteria into the Pentagon’s air conditioning system to observe how the microbes spread (the bacteria were reportedly harmless). In 1950, a U.S. Navy ship sprayed Serratia Marcescens—a common bacteria capable of minor infection—from San Francisco Bay. The bacteria floated over 30 miles, spread through the city, and may have caused one death.
A year later, during Operation DEW, the U.S. Army released 250 pounds of cadmium sulfide off the Carolina coast, which spread over 60,000 square miles. The military didn’t know that cadmium sulfide was carcinogenic, nor did it know that it could cause kidney, lung, and liver damage. In the 1960s, during Project 112 and Project SHAD, military personnel were exposed to nerve agents like VX and sarin and bacteria like E. coli without their knowledge. At least 134 similar experiments were performed.
President Nixon ended offensive tests of the US biological weapons program in 1969.