Description
Radon is a naturally occurring radioactive gas, derived from uranium, that is found in soil, water and rocks. Odorless, tasteless and colorless, radon gas decays over time into radioactive particles, which can be inhaled and trapped in the lungs.
Radon levels are generally highest in basements, where the gas seeps in from soil through cracks or pores in a home’s foundation, floor drains, sump pumps, joints and hollow-block walls. Radon has been found in homes all over the country.
Radon is the second leading cause of lung cancer after smoking. Children may be more sensitive to radon because they breathe faster than adults and due to their rapidly dividing cells, although some evidence shows that children exposed to radon may not have a higher risk of lung cancer. Exposure to both radon and tobacco smoke greatly increases the risk of lung cancer.
Health Effects
Immediate Health Effects
- If SWALLOWED, radon is Not Available
- If ABSORBED THROUGH SKIN, radon is Not Available
- If INHALED (SNIFFED OR BREATHED IN), radon is Not Available
Longterm or Delayed Health Effects
Other
- Lung cancer, lung tissue damage.
- Stomach cancer (from drinking radon-contaminated water).
How Exposures Occur
Building Materials
- Concrete, bricks, gypsum board (if mixed with talc and mica), granite, and slate sometimes contain radon that may be released into the home, but such cases are rare and do not constitute a great health risk.
From the Air
- Radon can be inhaled when indoor air is contaminated with radon that enters the home from radon-containing rocks and soil through joints, cracks, utility access points, and earthen foundations.
Radon levels in a home can fluctuate from day to day, depending on the level of radon in the soil, type of soil, airflow through soil, openings to buildings, ventilation, and precipitation (indoor radon is increased when the ground surface is saturated).
Water
- Water from privately owned wells can contain radon gas, particularly in homes with high levels of radon in the air. Radon contamination can also be a problem in communities that rely on groundwater for their water supply. Exposure from water occurs when gas is released from the water during showers and other household uses and inhaled. Most homes with public water sources are not at risk. Research suggests that swallowing water may pose a health risk, but this is much lower than breathing contaminated air.
Significant Statistics
High indoor radon levels (4 picocuries/liter or more) are found in nearly one out of every 15 homes.
Frequently Asked Questions About Radon. National Safety Council, Environmental Health Center.http://www.nsc.org/ehc/radon/rad_faqs.htm
Radon is estimated to cause 15,000 to 22,000 deaths per year.
A study in New York State showed that, while 82% of 1,209 residents had heard of radon, only 21% were knowledgeable about radon. Only 15% of those aware of radon had their homes tested.
Radon in drinking water causes about 168 cancer deaths per year, 89 percent from lung cancer caused by breathing radon released from water, and 11 percent from stomach cancer caused by drinking water contaminated with radon.
Proposed Radon in Drinking Water Rule. U.S. Environmental Protection Agency, Office of Water, Updated April 2000.http://www.epa.gov/safewater/radon/proposal.html
Solutions
How to detect radon
- Do-it-Yourself Tests: Home testing kits are affordable and easy to use. There are two types of test: short-term (2 to 90 days) and long-term (over 90 days). Radon levels tend to vary from day to day and season to season, so a long-term test better indicates your year-round average. In either case,the tests are conducted similarly, requiring that the test kit be left undisturbed on the lowest livable floor of the house, such as the basement,for the recommended duration of time. The test kits must be sent to a laboratory for analysis. Nearby buildings may contain varying amounts of radon so each building should be tested individually.
The U.S.Environmental Protection Agency’s Radon website provides explanations of the various types of tests. Test kits are available at most hardware stores, and others can be found at state and local health departments, from The National Safety Council, or mail-order sources. Look for a test kit from a company that is state-certified or EPA-listed.
- Professional Tests: Professionals may also be hired to radon tests. The EPA recommends contacting one of your state radon and air quality professionals. Both the National Radon Safety Board and the National Environmental Health Association list certified radon measurement professionals.
- To determine if your home is located where radon is a common problem, download the U.S. Environmental Protection Agency’s Radon Zone map.
How to minimize exposure to radon
- Methods:There are several ways to reduce radon inside the home, designed either to prevent radon entry into the house, or removing the radon once it has entered the home.
Ventilation: Reduce the amount of radon build-up that occurs in closed spaces (including crawl spaces under the house) by increasing the circulation of fresh air. Open windows and vents and use fans.
Sealing: By caulking cracks and filling gaps in in basement walls, floors and crawl spaces, radon can be blocked from entering the home. However, since it is very difficult to find all the entry points and because most homes cannot be made perfectly air-tight, this method is not sufficient when radon levels are high.
Diversion: This method involves physically channeling radon contaminated air outside. There are several ways to do this, such as with an exhaust fan, or through depressurization (see below).
Depressurization: This prevents the radon gas from being sucked into the house and can even be used to push the radon gas out through holes in the foundation. There are several methods. Sub-Slab Depressurization pulls radon-laden air from beneath the foundation and vents it outside the home. The system requires the use of a fan and a pipe inserted through the foundation and run to a point outside the shell of the house.
Sub-Membrane Depressurization requires the use of a plastic barrier over the soil as a collection cover.
Blockwall Depressurization uses a fan and ducts to draw suction on the hollow interior cavities of a concrete block wall.
The The National Safety Council Fix-It Program will provide guidance to consumers with high levels of radon free of charge. You can call them toll free, 800-644-6999.
- Professional Abatement: If short-term radon test results show that levels are higher than 4 picocuries/liter, conduct a follow-up test to confirm the results. If either the long-term follow-up test or the average of the first 2 short-term tests is 4 pcI/l or more, the home needs to be fixed,and a radon professional should be contracted. Hire contractors who are certified by either the National Radon Safety Board and the National Environmental Health Association and your state. Remember to retest after work has been completed.
The The National Safety Council Fix-It Program will provide guidance to consumers with high levels of radon free of charge. You can call them toll free, 800-644-6999.
Alternatives
- Make Your Home a Smoke-Free Zone: The risk of lung cancer from radon exposure is increased for smokers and those exposed to secondhand smoke.
- When building a new home or building, use radon-resistant construction techniques. For more information, see publications listed below.
For More information
Books, articles, factsheets and reports
A Citizen’s Guide To Radon: The Guide to Protecting Yourself and Your Family From Radon. U.S. Environmental Protection Agency, Indoor Environments Division, September 1992.
http://www.epa.gov/iaq/radon/pubs/citguide.html
Home Buyer’s And Seller’s Guide To Radon. U.S. Environmental Protection Agency, Office Of Air and Radiation, July 2000.
http://www.epa.gov/iaq/radon/pubs/hmbyguid.html
Model Standards and Techniques For Control of Radon in New Residential Buildings. U.S. Environmental Protection Agency, Office Of Air and Radiation, March 1994.
http://www.epa.gov/iaq/radon/pubs/newconst.html
“Radon: Worth Learning About,” Consumer Reports, Vol. 60, No. 7 (1995), pp. 464-5.
Brookins, Douglas G. The Indoor Radon Problem. New York: Columbia University Press, 1990.
Cole, Leonard A. Element of Risk: The Politics of Radon. Oxford University Press, 1994.
Radon-Resistant New Construction (RRNC) U.S. Environmental Protection Agency, Indoor Air Quality.
http://www.epa.gov/iaq/radon/construc.html
Other government agencies
U.S. Environmental Protection Agency, Office of Air and Radiation
1200 Pennsylvania Avenue, NW
Washington DC 20460
http://www.epa.gov/iaq/radon/index.html
U.S.Environmental Protection Agency, Office of Water
1200 Pennsylvania Avenue NW
Washington DC 20460
Safe Drinking Water Hotline: 800-426-4791
http://www.epa.gov/safewater/
Lawrence Berkeley National Laboratory, Indoor Environment Department
Berkeley,CA 94720 USA
510-486-5910
http://eande.lbl.gov/IE.html
Water Quality Association
4151 Naperville Road
Lisle,IL 60532
630-505-0160
http://www.wqa.org
National Safety Council
1121 Spring Lake Drive
Itasca, IL 60143-3201
National Radon Hotline: 800-767-7236
National Radon Helpline: 800-557-2366
National Radon Fix-It Line: 800-644-6999
http://www.nsc.org/issues/radon/
Nonprofit organizations
The American Lung Association
1740 Broadway
New York, NY 10019
800-LUNG-USA
212-315-8700
http://www.lungusa.org
National Radon Safety Board
PO.Box 741093
Arvada,CO 80006-1093
866-329-3474 (toll free)
303-403-1074
http://www.nrsb.org
Community Environmental Health Resource Center (CEHRC)
A resource site for advocates working to protect children from environmental health hazards in housing.
http://www.cehrc.org/tools/radon/index.cfm
Other websites
State Radon Websites
http://www.nsc.org/ehc/radon/radonlnk.htm
Center for Public Health and Law's Database of State Indoor Air Quality Laws
http://www.eli.org/research/iaqdatabases2004
