NOTE - the numbers used below are from the U.S. Nuclear Regulatory Commission and the American Nuclear Society and are updated from the original data we published here before 2003)
In deciding whether to visit ground zero at Trinity Site, the following information may prove helpful.
Radiation levels in the fenced, ground zero area are low. On an average the levels are only 10 times greater than the region´s natural background radiation. A one-hour visit to the inner fenced area will result in a whole body exposure of one-half to one millirem.
To put this in perspective, a U.S. adult receives an average of 360 millirems every year from natural and medical sources. For instance, the American Nuclear Society estimates we receive between 26 and 96 millirems every year from the sun - depending on what elevation we live. We receive about 40 millirems every year from our food. Living in a brick, stone, adobe or concrete house adds seven millirems of exposure every year compared to living in a frame house. Finally, flying coast to coast in a jet airliner gives an exposure of about two millirems on each trip.
One source of radiation exposure that was not considered in old calculations is from radon gas. Scientists now estimate that Americans average 200 millirems of exposure per year because of it.
Although radiation levels are low, some feel any extra exposure should be avoided. The decision is yours. It should be noted that small children and pregnant women are potentially more at risk than the rest of the population and are generally considered groups who should only receive exposure in conjunction with medical diagnosis and treatment. Again, the choice is yours.
At ground zero, Trinitite, the green glassy substance found in the area, contains several radioactive elements and is an alpha and beta particle emitter.
Typical radiation exposures for Americans per the American Nuclear Society
- One hour at Trinity Site ground zero = one half mrem
- Cosmic rays from space = 47 mrem at Denver per year, 28 mrem at St. Louis
- Radioactive minerals in rocls and soil = 63 mrems per year on Colorado Plateau
- Radioactivity from air, water and food = about 240 mrem per year
- About six mrem per chest X-ray, 65 mrem per hip X-ray and 110 mrem for a CAT Scan
- Watching television = less than one mrem per year
- Wearing a plutonium-powered pacemaker = 100 mrem per year
If you would like to estimate your own annual exposure to radiation, visit the American Nuclear Society´s website and print their form - it is a pdf file and requires Acrobat Reader to open the page.
Another source of information about radiation is the U.S. Nuclear Regulatory Commission´s website.