Operation Sea-Spray

In late September 1950, a Navy minesweeper sailing off San Francisco sprayed clouds of two bacteria, Serratia marcescens and Bacillus globigii, into the sea breeze blowing over the city. Both were then thought harmless and easy to trace; Serratia makes a bright red pigment. Monitoring stations around the bay found that nearly everyone in San Francisco had inhaled the particles, showing how vulnerable a coastal city would be to a real biological attack. Within days, eleven patients at Stanford University Hospital, then located in San Francisco, developed rare Serratia urinary infections, and one, Edward Nevin, died.¹

The test was one of many. With the Soviet Union building germ weapons, the U.S. Army and Navy ran open air trials using simulant bacteria and chemicals over places including St. Louis, Minneapolis and the New York subway. The public learned of Sea-Spray through press reports in 1976, and in 1977 the Army told a Senate subcommittee it had conducted 239 open air tests between 1949 and 1969. Nevin's family sued, but courts ruled the government immune from liability, and the Army maintained the Stanford infections were unrelated to the spraying.²³