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SOLID WASTE & HAZARDOUS MATERIALS
What is Radon?
Radon is a naturally occurring, cancer-causing radioactive
gas. It is produced by the normal decay of uranium,
an element that is found in nearly all soils. Impossible
to detect without a test, radon gas is colorless, odorless,
and tasteless.
Radon gas levels in California.
To date, surveys indicate that elevated radon levels
can be found in any part of the state. The estimated number of California
homes exceeding the recommended U.S. Environmental Protection Agency's
(EPA's) action level of 4 picoCuries is roughly one percent, or
approximately 100,000 homes. The California Department of Health
Services (DHS), along with the U.S. Geological Survey (USGS) and
EPA, have identified several areas with a higher-than-statewide-average
of homes with high radon levels. These areas include sections of
Santa Barbara, Ventura and Los Angeles counties. Ongoing testing
by DHS in these and other counties continues to identify areas of
high radon potential.
In addition to geographic location, other factors can
affect radon levels, such as house structure, soil! house pressures,
climatic conditions, and soil permeability. If you are concerned
about radon gas, DHS recommends testing. Testing is the only way
to determine the radon level in your home.
What are the health risks of radon?
The U.S. Surgeon General has warned that radon is the
second leading cause of lung cancer in the United States -- after
smoking. A known human carcinogen, radon is estimated to cause approximately
1,100 lung cancer deaths per year in California. DHS and EPA believe
that any radon exposure carries some risk --no level of radon is
safe.
How can radon affect you and your family?
Everyone who breathes is at risk from radon. As radon
decays, it changes into other radioactive elements. These elements
can become trapped in the lungs as the radon decay process releases
energy in the form of particles. Over the course of a lifetime,
this process can damage lung tissue and increase the risk of lung
cancer.
Your risk of developing lung cancer from radon
gas depends on:
- How much radon is in the home.
- The amount of time spent at home.
- Whether you are a smoker (or if you have ever smoked
- smoking combined with radon is an especially serious lung cancer
risk).
How does radon enter the home?
Typically, radon gas moves up through the soil into
your home through cracks in the foundation and walls, pores in hollow-block
walls, and gaps in suspended floors and around service pipes.
Homes often draw in radon because of differences in
pressure caused by a variety of factors. Your home can trap radon
inside, where it can build up to elevated levels.
Radon can also be present in well water, which then is released
into the air by showering or other water usage. In most cases, radon
in water is a small risk compared to radon gas entering the home
from the soil.
How is radon gas detected?
Since you can't see, smell, feel or taste radon gas,
you need specialized equipment to test for it. The types of commercially
available detectors that can be purchased by home owners are:
- Charcoal canister (or liquid scintillation device)
designed for short-term screening (two to seven days).
- Filtered or unfiltered alpha track detector for
longer-term measurement (generally three months to one year).
 These
detectors usually cost less than $20, which includes postage and
the test report.
All types of detectors are acceptable, but since the
amount of radon gas escaping from the ground varies from day-to-day
and season-to-season, the longer-term test will give you a more
representative assessment of your actual radon gas exposure.
Test kits are available in some hardware stores and
home improvement centers. Whether using a short-or long-term
test, use a device that is state-certified by DHS. A list of mail-order
companies handling certified detectors is available from DHS. If
you wish to hire a company to conduct testing for you, make sure
it is also certified by DHS.
What do test results mean?
Radon gas is measured in picoCuries per liter (pCi/L).
Average radon concentrations range from about 0.4 pCi/L outdoors
to around 1.3 pCi/L indoors. If short-term tests register levels
of 4 pCi/L or higher, DHS and EPA recommend testing with a long-term
test (for a better understanding of your year-round average). If
you need results right away, verify the first test with a second
short-term test. If results are still above 4 pCi/L, you should
correct the problem. Radon levels below 4 pCiIL still pose some
risk, therefore you may wish to consider further reductions. The
higher the radon level, the greater the risk of lung cancer.
What if the test results are high?
There are several methods of lowering radon levels
in your home. Some techniques prevent radon from infiltrating, while
others reduce the radon gas after it has already entered the home.
Usually, DHS and EPA recommend those methods that prevent the entry
of radon.
Lowering high radon levels requires technical knowledge
and special skills; therefore a trained contractor should be used.
DHS can provide a list of state-certified contractors. The cost
of making repairs to reduce radon gas depends on a variety of factors,
but for most homes such repairs will range from approximately $500
to $2,500.
Radon tests and contractors must be certified.
To ensure consumer protection, DHS regulates the radon
service industry through a state certification program. Any company
providing radon services to the public must be certified and provide
its certification number to clients.
Also, California has a real estate disclosure law that
requires the disclosure of known environmental hazards, including
radon, by the seller to the buyer. |
