during hard physical labor. Supplied-air respirators were used during the biomedical study program.
These provided positive pressure inside protective clothing so that any leaks would be outwards to prevent contaminants from entering the suit. After the extent of hazardous conditions in the test area was determined, workers were given the option of wearing supplied-air respirators or full-face filter respirators. As restrictions were further reduced, half- face respirators with high-efficiency filters were adopted for areas with less than 100 micrograms of plutonium contamination per square meter. All participants in field activities for Project 57 received bioassay tests to check for exposure to plutonium.
These tests consisted primarily of nasal swabs and, occasionally, urinalysis.
Once members of Task Group 57 had mapped the extent and distribution of the remaining plutonium contamination within Area 13, the contaminated zone was fenced off and posted with signs denoting Internal Radiation Hazard to unprotected personnel. Warning signs were also posted at the equipment burial trench, approximately 300 feet west of the "No. 36 Marker" on Valley Road.
The Project 57 site lay abandoned and nearly forgotten for almost 20 years as nearby Watertown (designated Area 51 in June 1958) grew into a thriving clandestine flight test center.
Return to Area 13
Map illustrating radioactive contamination levels within the fenced section of Area 13.
In the 1970s, the contaminated area was studied by the DOE Nevada Applied Ecology Group (NAEG) to estimate the amount and distribution of plutonium in the soil. NAEG scientists took numerous soil samples for analysis. In 1974, A. Wallace and E. M. Romney (UCLA Laboratory of Biomedical and Environmental Sciences) inspected the Area 13 test plots to evaluate vegetation recovery and compare soil surface conditions. They found that the plowed and