72 © The Containment of Underground Nuclear Explosions Figure 4-8—Sampie Press Release Alamo, NV July 11 to July 20, 1988 The Nevada Test Site COMMUNITY RADIATION MONITORING REPORT Dell Sullivan, Manager of the Community Radiation Monitoring Station in Alamo, NV reported the results of the radiation measurementsat this station forthe period July 11 to July 20, 1988. The average gammaradiation exposure rate recorded by a Pressurized Ion Chamber at this station was 13.0 microroentgens* per hour as shown on thechart. AVERAGE GAMMA RADIATION EXPOSURE RATE RECORDED ON THE PRESSURIZED ON CHAMBER AT ALAMO, NV, DURING THE WEEK ENDING JULY20, 1988 | i U S.Background? | 0 fy Last Year- | z\ “70 Last Week - ” SBD This Week "Min, 1 1 i ' i 1 1 10 20 Microroentgens Per Hour The averages of the 16 Community Monitoring Stations operated for the Environmental Protection Agency, Department of Energy and the Desert Research Institute varied from 6.2 microroentgens per hour at Las Vegas, NV to 20.2 microroentgens per hour at Austin, NV. All of the rates for the past week were within the normal background range for the United States as shown on the accompanying chart. Environmental radiation exposure rates vary with altitude and natural radioactivity in the soil. Additional information and detailed data obtained from Community Radiation Monitoring Network Stations, including an annual summary of the results from all monitoring aroundthe Nevada TestSite, can be obtained from Mr. Sullivan (702) 725-3544 or by calling Charles F. Costa at the EPA in Las Vegas (702) 798-2305. “The roentgen is a measure of exposure to X or gamma radiation. A microroentgen is 1 millionth of a roentgen. For comparison, one chest x-ray results in an exposure of 10,000 to 20,000 microroentgens. t Sum of cosmic plus terrestrial dose rates in air in the U.S.(pp37,42, BEIR III, 1980). Example of community radiation monitoring report that is posted at each monitoring station and sent to the press. SOURCE. Environmental Protection Agency.