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Most of the exposure levels described in these Web pages are averages and
may not reflect your own individual exposure or that of members of your family.
Depending on where you live, your lifestyle, and your occupation, you could
be exposed to more or less radiation than the average person.
For example, if you live in "mile-high"
Denver, Colorado, your average annual dose
from cosmic radiation is about 50 millirem
per year. If you live in Leadville, Colorado,
at an altitude of two miles, your cosmic
radiation dose is closer to 125 millirem per
year. However, if you live on a coastal plain,
like Florida, you receive only about 26 millirem
per year from cosmic radiation.
Some parts of the country have higher concentrations
of radon and radioactive minerals
in the soil than others. In Ohio, for
example, a line of Ohio Black Shale runs
through the center of the state from south
to north, along part of the Lake Erie shore,
and in the northwestern parts of the state.
Many people who live over this shale experience
higher doses from radon than those
who live elsewhere in Ohio. Also, very
high levels (hundreds or even thousands of
pCi/L ) of radon have been found in homes
built in the area known as the Reading
Prong in the Northeastern United States.
Other factors that help determine your
exposure include:
- The consumer products you use regularly
- The number of medical and dental procedures using radiation that you undergo annually
- The kind of work you do. (Airline flight crews receive many times the average radiation exposure from cosmic rays while in the air, an extra 100 millirem per year on average.)
- Whether you smoke
- The kind of house you live in
You can use Table 4 to do a rough calculation
of your annual exposure to radiation.
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Table 4. What Is Your Estimated Annual Radiation Dose? |
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Source |
Your Average Annual
Dose (mrem) |
| Cosmic radiation at sea level (from outer space) | 26 |
What is the elevation (in feet) of your town?
- up to 1000, add 2 mrem 5,000 - 6,000, add 29 mrem
- 1,000 - 2,000, add 5 mrem 6,000 - 7,000, add 40 mrem
- 2,000 - 3,000, add 9 mrem 7,000 - 8,000, add 53 mrem
- 3,000 - 4,000, add 15 mrem above 8,000, add 70 mrem
- 4,000 - 5,000 add 21 mrem
| |
Terrestrial (from the ground):
What region of the US do you live in?
- Gulf Coast, add 16 mrem
- Atlantic Coast, add 16 mrem
- Colorado Plateau, add 63 mrem
- Elsewhere in United States, add 30 mrem
| |
Internal radiation (in your body):
From food and water, (e.g., potassium and radon in water) | 40 |
| From air, (radon) | 200 |
| Do you wear a plutonium powered pacemaker? If yes, add 100 mrem | |
| Do you have porcelain crowns or false teeth? If yes, add .07 mrem | |
Travel Related Sources:
Add .5 mrem for each hour in the air | |
| Are xray luggage inspection machines used at your airport? Yes, add .002 mrem | |
| Do you use a gas camping lantern? If yes, add .2 mrem | |
Medical Sources
X-rays:
- Extremity (arm, hand, foot, or leg) add 1 mrem
- Chest xrays, add 6 mrem
- Skull/neck, add 20 mrem
- Upper GI, add 245 mrem
- Dental xrays, add 1 mrem
- Pelvis hip, add 65 mrem
- Barium enema, add 405 mrem
CAT Scan (head and body), add 110 mrem
Nuclear Medicine (e.g., thyroid scan), add 14 mrem
| |
Miscellaneous Sources:
Weapons test fallout | 1 |
| Do you live in a stone, adobe brick, or concrete building? If yes, add 7 mrem | |
| Do you wear a luminous wristwatch (LCD)? If yes, add.06 mrem | |
| Do you watch TV? If yes, add 1 mrem | |
| Do you use a computer terminal? If yes, add .1 mrem | |
| Do you have a smoke detector in your home? If yes, add .008 mrem | |
| Do you live within 50 miles of a nuclear power plant? If yes, add .01 mrem | |
| Do you live within 50 miles of a coal fired power plant? If yes, add .03 mrem | |
| TOTAL YEARLY DOSE (in mrem): | |
| [Note: The amount of radiation exposure is usually expressed in a unit called millimrem (mrem). In the United States, the average person is exposed to an effective dose equivalent of approximately 360 mrem (whole-body exposure) per year from all sources (NCRP Report No. 93).] |
| Source: U.S. EPA and American Nuclear Society based on data from the National Council on Radiation Protection and Measurements Reports # 92 - 95 and #100. |
December 10, 2002
Copyright 2001, 2002 * All Rights Reserved
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