Los Alamos National Laboratory irradiating Americans since 1943
Radiation
Background radiation Human-products
Although some radiation is the result of human activities,
most radiation comes from natural sources. Earth
and its inhabitants are exposed to naturally occurring
radiation every day, Background radiation includes
natural radiation and a very small amount of man-made
contributions from our various uses of radioactivity.
Although our understanding of radiation is relatively
new and is constantly being improved, radiation has
always been a part of life on Earth.
Radiation from cosmic rays and terrestrial sources (for
example, radon released as natural uranium in rocks
decays to radium and then to radon) contributes the
most to an individual's estimated dose. Compared with
the national average, Los Alamos and White Rock
residential areas have more naturally occurring radiation
because of the high altitude and naturally occurring
uranium in rocks and soil. The total dose from background
radiation, greater than 99% of which is from
natural sources, is about 360 mrem in this area and can
easily vary by 10 mrem from year to year.
Human-produced radiation
Medical procedures and industrial operations also
produce radiation. Medical x-rays are a source of
radiation, as are consumer goods such as. tobacco
products, porcelain dentures, television sets, and smoke
detectors. Some of the radiation in the environment is
due to fallout from past weapons testing in various
countries and to nuclear research.
Pathways
Both background and human-produced radiation have
the potential to reach the public. A pathway outlines the
route a radioactive contaminant may follow to reach
the human population. Radioactive releases may enter
the local environment by air or water and pass through
soil, plants, livestock, or wildlife, ultimately reaching
humans through inhalation, ingestion, absorption
through skin or wounds, or external exposure, i.e.,
direct irradiation of the body.
Dose
The effects of radiation arc related lo dose, which is the
amount of radiation received and is measured in
millirem. To protect public health and safety, 1)01?
maintains dose limits biased on guidance from the
Environmental Protection Agency, the National Council
on Radiation Protection and Measurements, and the
International Commission on Radio-logical Protection.
The DOE'S public dose limit is 100 millirem per year
for all radiation that results from operations at the
Laboratory.
In 2001, the maximum potential public doses were 4.2
millirem on-site and 1.9 millirem off-site. A person
who travels frequently on Pajarito Road and is near
TA- 18 during several experiments could potentially
receive the 4.2. millirem on-site dose. A person who
works or resides continuously at East Gate, north of
TA-53, could potentially receive the 1.9-millirem offsite
dose.
The Environmental Protection Agency limits the dose
to any member of the public from radioactive airborne
releases from the Laboratory to I0 millirem per year.
The 2001 maximum dose from airborne releases is
calculated to be I .84 millirem and is to an individual at
East Gate north of TA-53.
absorbed (dose) an
effect on the body (
resulting from the different types
radiation.
mrem = 1 /'I 000 rem
Risk
In March 1996, the Health Physics Society published a
position paper on the risks of radiation exposures. They
concluded that below an individual dose of 5,000
millirem in one year "risk estimates should not be used;
expressions of risk should only be qualitative emphasising
the inability to detect any increased health
detriment (i.e., zero health effect is the most likely
outcome)." They further noted that health effects
(primarily cancer) from radiation exposure are observed
in humans only at doses in excess of 10 rem, or
10,000 millirem, delivered at intense dose rates.
The risk of cancer mortality for every United States
resident is one chance in five. The added risk caused
by Laboratory operations is too small to measure. (well they would say that wouldn't they)
Total contributions to 2001 dose for
the Laboratory's maximally
exposed individual.
