Yet Another Case for Mack Brain

Secret biological warfare tests in the 40's and fifties included the US Navy spraying San Francisco with a huge amount of what turned out not to be entirely benign bacteria.

But in at least one case -- the bacterial fogging of San Francisco -- the research may have gone awry. Between Sept. 20 and Sept. 27 of 1950, a Navy mine-laying vessel cruised the San Francisco coast, spraying an aerosol cocktail of Serratia and Bacillus microbes -- all believed to be safe -- over the famously foggy city from giant hoses on deck, according to declassified Army reports. According to lawyers who have reviewed the reports, researchers added fluorescent particles of zinc-cadmium-sulfide to better measure the impact. Based on results from monitoring equipment at 43 locations around the city, the Army determined that San Francisco had received enough of a dose for nearly all of the city's 800,000 residents to inhale at least 5,000 of the particles.