Problem: Radon gas is present
in amounts large enough to cause potential health
Background: Radon is a colorless, odorless,
tasteless radioactive gas that is present naturally in the
environment. Radon is produced from the radioactive decay
of uranium. Very small amounts of uranium and radium are
present in almost all rocks and soil, so radon is
constantly being produced almost everywhere. Exposure to
radon and its decay products can cause lung cancer; the
greater the amount and the longer the exposure, the
greater the risk. For information on other indoor air
Pollution in Home.
What to do: Like all gases, radon moves from high
to low pressure by airflow, and from high to low
concentrations by diffusion, or mixing. If a building
provides an easier route, radon gas may enter, become
trapped, and eventually decay. (Underground water and some
building materials can also emit radon.) Radon can enter a
home through sewer pipes, sump pump openings, cracks in
the basement floor and walls, and private wells. A drop in
air pressure inside a house can help pull the radon
indoors from the surrounding soil. This pressure drop can
be created by some mechanical systems, furnace operation,
or the use of combustion devices.
Most efforts to reduce radon risks in homes center on
reducing the entry of radon gas. (Air-cleaning devices may
actually increase the problem.) You can buy relatively in
expensive canister or alpha-track detectors to test for
radon in homes. The canisters with activated char coal are
exposed for 48 hours in a closed home and sent to a lab.
Alpha-track detectors have a plastic disc which is struck
by alpha particles given off by radon decay. The disc,
exposed in the home for a period of up to a year, is then
read by a lab.
Special advice: High radon levels vary by area
within the United States. Alpha-track detectors, which
measure long-term averages, are of more value because
health risk is related to long-term exposure. When using
charcoal canisters, follow directions and keep away from
areas of high temperature, humidity, or drafts.
Professionals in your area also may have more expensive
direct-reading instruments to detect radon in your home.
They may be set for average results, or to “sniff’ out
sources of radon.