Radon: Risks, Avoidance, and Testing Your Home

What is Radon?

Being the second leading cause of lung disease in the United States with numbers reaching to 15,000 to 22,000 deaths per year, according to the National Academy of Science, radon exposure is a serious public health concern. Radon is a radioactive gas, both odorless and tasteless, invisibly released from the normal decay of uranium in rocks and soil, which seeps up through the ground and diffuses in air (National Cancer Institute). Due to the emitting of atomic particles as it breaks down, which can increase lung cancer risk and potentially alter DNA, the severity of radon is evident, being classified as a “Class A” carcinogen, according to the EPA. Radon death risk for the average person at home is 1000 times higher than the risk from any other carcinogen regulated by the FDA and EPA (“Radon Risk Assessment,” 2004). Ranking second to drunk driving for preventable causes of death, radon is higher than drowning, fires, and airline crashes.

Radon Informational Video: http://www.youtube.com/watch?v=frciP5_hylU&feature=related

Risks of Radon

Radon found in the home is dangerous not only to adults and children, but visitors that come into the home due to the risk of exposure. Indoor radon concentrations are due in part to specific characteristics of a residence and environmental factors (“Radon Risk Assessment,” 2004), in addition to occupants and their lifestyles. Typically, the highest radon levels are found in the lowest level of the house, however during colder months or climates, the radon levels are elevated to higher floors (“Radon and Cancer: Questions and Answers,” 2004). Warm air in a house rises and leaks out of attic openings and around upper floor windows, which creates a small suction at the lowest level of the house. This air flow subsequently pulls the radon out the soil and into the house (Martin, G.T., 2000). Radon has the potential to enter homes through cracks in floors, walls, foundations, and collect indoors. Other ways radon can enter a home include release from building materials, water from radon-containing wells, tightly sealed/insulated homes, or a residence built on uranium-rich soil (“Radon and Cancer: Questions and Answers,” 2004).

You may be interested to know that everyday people breathe in low levels of radon since it is present in nearly all air. The risk of lung cancer becomes elevated when the levels of radon inhalation are increased, which causes the radioactive particles to damage the cells lining the lung (“Radon and Cancer: Questions and Answers,” 2004). According to the EPA, the guideline for lifetime exposure to radon level is 4 pCi/L, which will create a risk of 1 to 5% of lung cancer development (enhs.umn). Factors that have been found to influence the risk of lung cancer from radon exposure include:
• Age
• Gender
• Physical condition
• Duration of exposure
• Time since initiation of exposure
• Cigarette smoking
• Other carcinogenic exposures
• Genetic tendency either to resist or be affected by internal radiation exposure
• Geographic location

Age – Children tend to be more susceptible to radon exposure than adults, due to longer latency periods to develop cancer, different breathing patterns, and lung structure. Subsequently, children have larger doses of radon in the respiratory tract. On average, children spend a majority of time at home or in the basement, 70% more time than adults, which increases the risk of domestic radon exposure (“Radon Risk Assessment,” 2004).

Gender - According to research, the risk of lung cancer due to radon exposure is different for men and women because of varying gender-related factors and lung dosimetry. Opposite of males, women typically have lower rates of lung cancer incidence, even when considering a smoking history (which elevates the risk) (“Radon Risk Assessment,” 2004).

Lung cancer risks from exposure to Radon-222 at 1 Bq/m3
Ever-Smokers Never-Smokers
Men 3.1 x 10-4 0.59 x 10-4
Women 2.0 x 10-4 0.40 x 10-4
Population 1.6 x 10-4

Physical Condition - The risk of lung cancer development can be increased if an individual has a chronic respiratory disease, such as fibrosis, asthma, or emphysema. Having reduced expiration efficiency and increased residual volume, individuals with chronic diseases can have radon and radon remnants present in the lungs for longer periods of time. This longer exposure significantly increases the risk of lung tissue damage (Martin, G.T., 2000). Others who may be more susceptible to the risk of lung cancer are individuals who have existing lung lesions, which in turn can produce tumors in the lungs.

Duration of Exposure – The length of exposure time and radon concentration in the air increases the possibility of an individual developing lung cancer. There is an increase in risk of development due to the greater number of radon particles passing through the body since every particle has an impact.

Cigarette Smoking – According to the National Academy of Science, who conducted six research studies on miners, found that there was a “synergistic effect” of the two exposures, with the two exposures being those who smoke and those who do not smoke. From the study, it was found that the risk of lung cancer from radon exposure was ten to fifteen times greater for those who smoke, opposed to those who do not smoke (“Lung Cancer,” 2008). In the United States, the relevance between radon exposure and smoking to the number of lung cancer deaths found that of “every 100 persons who died of lung cancer, approximately 93 were current or former smokers, whereas 7 had never smoked” (“Lung Cancer,” 2008). However, in the home, it was found that radon causes 23% death rate among non-smokers, while only 7% in smokers. The current hypothesis of why smokers have a lower rate is due to a possible “higher retention” because of alterations in mucociliary clearance and mucus production.

Geographic Location – Information from the EPA reveals that the upper Midwest exhibits the highest radon concentration levels due to glacial deposits from over 10,000 years ago ((“Radon Risk Assessment,” 2004). Approximately 6 million or 6% of American homes have radon concentrations above 4 pCi/L, which is above the accepted limit of radon in the home increasing the risk of lung cancer (EPA). Although the only way of determining radon level concentration in the home is through testing, some homes are more predisposed than others due to: soil porosity, type of foundation, building materials, source of water supply, location, and building ventilation rates. Most homes found with higher than normal levels of radon were found to have larger deposits of granite, shale, phosphate, and uranium present.

Testing

The EPA recommends homeowners to have the home tested in order to reduce radon levels if the concentration is at or above 4 picocuries per liter or pCi/L. For those homes with levels exceeding the EPA’s standards that get the home tested and corrected, lung cancer deaths could be reduced by 2 to 4 percent or about 5,000 deaths per year (“Radon,” 2009).

Testing Video: http://www.youtube.com/watch?v=vgrIa3CXllU&feature=related

Before the Radon Test

Use a radon measurement device listed by EPA’s Radon Measurement Proficiency Program or certified by your state. It is important to conduct the radon test for a minimum of 48 hours for the detectors to get an accurate reading of radon levels. The EPA recommends that short-term radon testing is to be conducted under closed-house conditions, meaning that all windows and doors be kept closed, not using fans or other devices to bring in air from outside. It is vital to maintain the closed-house conditions for at least 12 hours before beginning the test and for the entire testing time if doing short-term (“Radon Testing,” 2009).

Detectors and Cost

Since radon levels seem to vary from day to day, there are two different types of detectors that can be used to test radon levels in the home, in which both are seemingly easy to use and fairly inexpensive (“Radon Testing,” 2009).
• Short-term Detectors: used to measure radon levels for 2 days to 90 days. Cost ranges from 9 to 12 dollars.
• Long-term Detectors: used to measure radon levels for more than 90 days

However, if you are unsure of the type of detector needed to test your home, contact a state or local radon official to explain about and recommend the best testing device. Cost ranges from 30 to 35 dollars.

During the Radon Test

It is important to not disturb the test device at any time during the test, in addition to maintaining closed-house conditions during the entire time the test is running. For tests lasting less than one week, only operate air conditioning units that recirculate interior air. If a radon reduction system is in place, make sure the system works properly and is in operation during the test (“Radon Testing,” 2009).

Radon Reduction

If high levels of radon are found, then the house needs to be fixed. After finding high levels of radon in the home contact a qualified radon reduction contractor to lower the home’s radon level. Home size and design are determinant on the cost of radon reduction in the home, depending on the methods needed. However, costs normally range from $800 to $2500 depending on the severity and level of radon in the home.

Research

A study conducted by the National Institute of Environmental Health Sciences in 2000 tested the radon exposure in residential areas in Iowa. Participants were females who had lived in current home for at least 20 years, and included 413 females with lung cancer and 614 females without lung cancer (Field, R.W., et al, 2000). The study involved homes being tested for radon levels, home characteristics examined, and lung cancer tissues examined, which provided a link between lung cancer and radon exposure.

Another study conducted in 2002 involved radon exposure in Swedish people who had not smoked daily for more than one year. Participants included 231 people without lung cancer and 110 people with lung cancer. Methods involved measuring radon levels in the home through regular testing devices, as well as glass testing. Again, results showed that there is a long-term radon exposure link to lung cancer.


References

Field, R.W., Steck, D.J., Smith, B.J., Brus, C.P., & Fisher, E.L. (2000).

Residential radon gas exposure and lung cancer: the Iowa radon lung cancer study. American Journal of Epidemiology, 151(11), Retrieved from http://radsci1.home.mchsi.com/irlcs.pdf.

Lung cancer. (2008). Retrieved from http://www.dhss.mo.gov/Cancer
inMissouri/LungCancer.pdf.

Martin, G.T. (2000, January 27). Understanding radon. Retrieved from
http://www.discoverit.com/at/phi/article.html.

Missouri Department of Health and Senior Services - Radon. (2009).
Retrieved from http://www.dhss.mo.gov/Radon.

Radon and cancer: questions and answers. (2004, July 13). Retrieved from
http://www.cancer.gov/cancertopics/factsheet/Risk/radon.

Radon risk assessment. (2004). Retrieved from http://enhs.umn.edu/hazards/
hazardssite/radon/radonriskassessment.htm.

Radon testing. (2009). Retrieved from http://www.dhss.mo.gov/Radon/
Testing.html.