HOW TO : TEST FOR RADON IN YOUR HOME
Radon is an odorless, colorless radioactive gas occurring naturally in the earth’s rock and soil. It is the product of decaying soils and rocks associated with high levels of uranium including granite, phosphate, shale and pitchblende.
As radon decays, it produces heavy radioactive byproducts called “progeny” that cling to dust and smoke. When inhaled, progeny continues to decay inside the lungs, which can lead to lung cancer.
Fortunately, in Orange County, relatively few “hot spots” (areas where high levels of radon have been recorded) exist. In a 1990 survey, the Environmental Protection Agency worked with the California Department of Health Services to randomly place short-term radon canisters in 2,000 California homes. Of those homes, 41 canisters were distributed throughout Orange County. While short-term findings reassured county residents that radon levels are low, periodic testing is recommended.
“Houses built on a hillside, especially houses in the canyons, have a higher chance of radon poisoning,” said Diane Masseth-Jones, director of environmental health for the Orange County chapter of the American Lung Assn. “For Orange County, this is a question of what is in the soil beneath your house and how well the house is ventilated. To ease any worries, simply monitor radon levels in the home.”
FREQUENTLY ASKED QUESTIONS REGARDING RADON
* How does radon get inside the home? High levels of radium (a chemical element of uranium) found in the soil are responsible for radon in the home. As radium breaks down, it produces a gas--radon--that rises from the soil into the home or building. Radon enters through gaps and cracks in the foundation or in the insulation, or through pipes, drains, walls.
* What health risks are associated with long-term indoor radon exposure? Radon exposure ranks second only to cigarette smoking as the leading cause of lung cancer in the United States. The EPA estimates that 5,000 to 20,000 lung-cancer deaths each year may be attributed to radon exposure. Further, health risks vary with the ages of those living in the home (e.g., the tiny lungs of an infant are more susceptible to radon poisoning).
* How are radon levels measured? Two types of monitoring devices are available at most hardware stores: On a short-term basis, charcoal canisters are used to collect radon over a two- to four-day period. Long-term devices, called alpha-track detectors, monitor radon levels over a period of months to a full year. Radon is measured in the number of picocuries per liter of air (pCi/1). A picocurie equals one-trillionth of a curie, a standard measurement for radiation.
* What are the advantages to monitoring radon over a longer period? Radon levels may vary daily, weekly or seasonally depending on climate, indoor ventilation or heating systems in use. Long-term monitoring provides a more accurate average indoor radon level.
* What steps can be taken to reduce radon levels in the home? Ventilation is the key to keeping the home clear of high radon levels:
1. Open windows or doors, use fans or heat exchange units to increase
ventilation of fresh air.
2. Seal cracks in the foundation and along walls, floors or molding.
3. Be sure all crawl spaces are open and clear.
RADON RISK EVALUATION CHART
Radon is estimated to rank behind only cigarette smoking as the leading cause of lung cancer in the United States. The following chart shows the serious health risks involved with exposure to various levels of radon in the home. Whatever the radon level, the longer the period of exposure, the greater the health risk.
pCi/1* Comparable Radon Comparable Exposure Levels Lung Cancer Risk 200 1,000 times average outdoor level Eight packs of cigarettes a day 100 100 times average indoor level four pack-a-day smoker 40 40 times average indoor level 20,000 chest x-rays a year 20 100 times average outdoor level Two pack-a-day smoker 10 10 times average indoor level Five times non-smoker risk 4 20 times average outdoor level 200 chest x-rays a year 2 10 times average outdoor level Half-a-pack smoker 1 Average indoor level Non-smoker risk of dying from lung cancer 0.2 Average outdoor level 20 chest x-rays a year
* pCi/1 is a picocurie. A picocurie equals one-trillionth of a curie, a standard measure for radiation.
AREA RADON READINGS
The map shows a sample of the 12 highest radon readings collected in a random survey conducted by the EPA in 1989-90.
BUENA PARK: READING: 1.6 FULLERTON: READING: 1.6 PLACENTIA: READING: 1.6 ORANGE: READINGS: 1.0, 1.1, 1.3 LAGUNA HILLS: READING.2. (highest in county) MISSION VIEJO: READINGS: 1.1, 1.3, 1.4, 1.7 Source: Orange County chapter of the American Lung Assn., state Department of Health Services, United States Environmental Protection Agency.
