The primary
naturally occurring airborne contaminant that has been receiving
the most coverage as of late is Radon gas. Radon is a colorless,
odorless, tasteless, gas that occurs worldwide. It is a by-product
of the breakdown of naturally occurring Uranium in soil, rock, and
water and gets into the air being breathed. It is present in varying
quantities in the atmosphere and in soils around the world and is
a known carcinogen. Because Radon gas is radioactive, air inside
the home that possesses Radon may lead to the threat of lung cancer
for the occupants. A home may be trapping Radon inside allowing
it to build up to unhealthy levels increasing the chance of lung
cancer. The Surgeon General has created a health advisory concerning
Radon gas in the home because of this threat. "Indoor Radon
gas is a national health problem. Radon causes thousands of deaths
each year. Millions of homes have elevated Radon levels. Homes should
be tested for Radon. When elevated levels are confirmed, the problem
should be corrected."
Radon is undetectable by humans without
using special equipment to measure its concentration. Radon results
are measured and reported in either picocuries per liter (pCi/L)
or working levels (WL). The Environmental Protection Agency (EPA)
has set 4 pCi/L or 0.02 WL as the acceptable limits for Radon gas
in the home. Any readings above this are considered hazardous. There
are a variety of methods for testing Radon but the guidelines enumerated
in the EPA's Radon Measurement Proficiency Program (RMP) should
be followed to insure the most accurate test results. Each state
has Radon office that can assist in answering questions. Normally,
the Department of Environment or Air and Radiation Management handle
Radon questions.
Just how Radon enters the home can vary.
Radon typically moves up through the ground, through cracks and
other holes in the foundation, slab, sump pump openings, floor drains,
and pores in hollow brick walls to name a few. Radon can also seep
into ground water coming from wells and remain trapped there, entering
the home in the water being pumped from the well. Those on municipal
water supplies do not have as much risk from this type of problem.
Radon can be present in any home new or
old, well sealed or drafty, and with or without basements. Because
Radon is a gas, it concentrates most efficiently in the areas of
the home closest to the ground. Radon levels generally decrease
as one moves higher in the structure. It is believed that nearly
one out of every fifteen homes in the United States is estimated
to have higher Radon levels. Because people spend most of their
time at home, this is the most likely place for their greatest radiation
exposure. The EPA's risk assessments assume an individual is exposed
to a given concentration of Radon over a lifetime of roughly 70
years, and spends 75 percent of his or her time in the home.
Radon is harmful because it breaks down
into radioactive particles (called decay products). When inhaled,
Radon is trapped in the lungs where it decays emitting radioactive
particles that adversely affect the cells in the lungs contributing
to the development of lung cancer. Being a smoker exacerbates the
effects. The EPA estimates that the risk of dying from lung cancer
is as the result of an annual radon level of four picocuries is
equivalent to the risk from smoking two packs a day while a level
of 100 pCi / L equates to 2,000 chest x-rays a year. Radon is not
a serious problem outdoors because it is diffused by the ambient
air. The EPA has determined that short-term exposure to a high concentration
of Radon is not as severe a risk as long-term exposure to lower
levels of the gas. It is estimated that most homes will contain
from one to two picocuries of Radon per liter of air. If a Radon
test indicates Radon over four pCi / L, a long-term retest should
be considered. If Radon levels continue to be high (over 4 pCi/L)
there are a variety of effective and fairly inexpensive methods
the homeowner can pursue.
When trying to deduce where Radon may be
entering the house, the first and most likely suspects are all openings,
cracks, or bare dirt areas. Cracks in the foundation, slab and walls
may be allowing Radon to enter. These cracks should be filled and
monitored to insure they do not reopen thereby allowing Radon to
reenter. Uncovered sump pumps pit are another prime candidate for
allowing Radon encroachment. Covers can be purchased to cover the
pit and stop the Radon from entering. Gaps in suspended floors and
around service pipe entries should be eliminated as Radon can enter
through these. Another area to check is the water supply. Radon
gas can be carried into the house from the well and cause high readings.
If it is believed that the water may be carrying the Radon into
the house, the water can be tested and if necessary filtered to
stop the Radon entry. If these steps do not help, a professional
Radon remediator should be called.
If the need for a professional Radon contractor
arises, be sure they have a Radon Contractors Permit (RCP) issued
by the EPA and is registered with the state as a certified Radon
contractor and have their credentials with them before beginning
work. It does not hurt to shop around and obtain the best quote
for having the necessary work performed.
Radon gas can be found throughout the United
States. Although it is more prevalent the closer one lives to mountainous
regions, Radon can be found everywhere and should be considered
an environmental hazard that should be checked for periodically
and remedied if found to be present over 4 pCi / L. The national
hotline for Radon testing information is 800SOS-RADON. Another source
for Radon information is the Consumer Federation of America's (CIA)
Radon Fix-It program, 800.644.6999. These are helpful people who
can help with choosing a remediation company and other non-technical
question.
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