Radiation at Ground Zero
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
Soceity'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.
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