SAN FRANCISCO (CBS SF) — In what sounds like a conspiracy theory, the fog over San Francisco was used by the U.S. military in the 1950s as a way to maske the spreading of a biological agent in simulated germ-warfare attacks.

Leonard Cole, the director of the Terror Medicine and Security Program at Rutgers Medical School, called it one of the largest human experiments in history.

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For a period of 20 years between 1949 and 1969, the U.S. Army conducted more than 200 secret biological warfare tests over populated areas. Among the first was in the 1950s along San Francisco’s bay coastline.

A Navy minesweeper went back and forth for a couple of days in September spraying a bacteria called Serratia marcescens in a mist that was unnoticed due to the region’s fog.

In his book, “Clouds of Secrecy,” Cole said it was touted as harmless bacteria, but that wasn’t the case.

Nearly all of San Francisco received 500 particle minutes per liter. In other words, nearly every one of the 800,000 people in San Francisco exposed to the cloud at normal breathing rate (10 liters per minute) inhaled 5,000 or more particles per minute during the several hours that they remained airborne.

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Cole said a careful inspection of the medical literature would have shown that bacteria was responsible for not only making some people ill over the course of 50 years, but also in a few instances caused their death.

“Here’s an experiment involving human subjects, but the purpose of the experiment was not to see anything about the survival of the individuals,” Cole said.

Read More From Discover Magazine.



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