Wanted: Radon Gas
A Dirty Dozen Science Lab Gang Member
(Article #14)

RADON * The Earth Passes Gas!

Radon is a naturally occurring gas originating from the decay of uranium in the Earth. It seeps out of soil and rocks, well water, building materials and other sources at a varied rate. The rate depends on the amount of naturally occurring uranium present at the location. It has conclusively been shown in epidemiological studies involving underground miners to “cause” lung cancer. There is additional supporting evidence from experimental animal studies that confirm radon as a “cause” of lung cancer. Radon actually has been found to be the delivery vehicle from which alpha particles (from radon progeny) damage lung cells to cause cancer. The Environmental Protection Agency (EPA) classifies radon gas as a known human lung carcinogen.

So What's The Big Stink About?

Why should radon gas be a member of the “Dirty Dozen Science Lab” gang members? In addition to high concentrations in underground mines, radon is also found in buildings such as homes, offices and SCHOOLS. High concentrations indoors build up when it is unable to disperse. These high concentrations can be a cause for concern relative to increases in lung-cancer risk for individuals who spend long periods of time in contaminated buildings; e.g. a teacher in a science laboratory.

Radon is chemically inert. However, it is radioactive and spontaneously decays or changes to other atoms. These other atoms or radon progeny are electrically charged and attach themselves to dust particles in indoor air. The dust particles are then inhaled into the lung and adhere to the lining. The deposited atoms decay and emit alpha radiation, which causes cell damage to the lung.

The EPA reports that statistics and studies have suggested between 7,000 and 30,000 lung cancer deaths each year are a result of exposure to radon. Smokers are at higher risk of developing radon-induced lung cancer.

A nationwide survey of radon levels in schools estimated that 19.3% of U.S. schools have at least one frequently occupied ground-contact room with radon levels above the Action Level of 4 pCi/L. Approximately 73% will have only five or less schoolrooms with radon levels above the Action Level. The other 27% will have six or more such schoolrooms. (P 59 * Indoor Air Quality Tools for Schools, U.S. Environmental Protection Agency, 1995.

Bottom line is that for school children and staff, the second largest contributor to radon exposure is their school. Given this scenario, the EPA recommends that school buildings as well as homes be tested for radon.

Can You Pass The Test?

There are three ways to test for Radon.

A. Short-term Testing: Short-term testing is done for a 48-96 hour period. Given that radon levels may vary from day-to-day, it is suggested that at least two short-term tests be done.

B. Long-term Testing: Long-term testing is done for 90 days to one year give the most accurate readings. This test reveals average radon level for a long period of time.

C. Radon in Water Testing: Radon water testing is done by letting water run for approximately 3-5 minutes. Vials are used to collect samples and analyzed by a laboratory.

EPA protocol for testing includes the following:

Step 1: Conduct a short-term test. If results are 4 pCi/L or higher, take a second follow-up test.

Step 2: A follow up test should be taken immediately if the short-term test is 10 pCi/L or higher. If not, follow up with a second short or long term test.

Step 3: If a long-term test was used as follow up, remediate the building if readings were 4 pCi/L or more. If a short-term test was used as follow up, the higher the results, the greater the need for remediation. It is recommended that remediation be done if the average between the two tests is 4 pCi/L or more.

How To Clear The Air!

As a means of prevention, the EPA and Office of the Surgeon General recommend that all buildings below the third floor be tested for Radon. Buildings with levels higher than 4 pCi/L should be remediated. Radon levels less than 4 pCi/L still pose a risk and in many cases, should be reduced. A 1991 survey showed the average indoor radon level was 1.3 pCi/L in the United States. The average outdoor level was about 0.4 pCi/L.

In buildings, sources of entry for radon gas include cracks in foundations, construction joints, cracks in walls, gaps around pipes, gaps in flooring and water supplies.

And What Of The Water?

Drinking water also poses a threat. Radon gas is dissolved in water and is released into the air via water faucets, showerheads, etc. Schools and homes on well water should be tested for radon levels. Remember that the levels can vary from day-to-day depending on the source of water. Water delivery sources such as sinks faucets, fountains spouts, showers heads, etc. disperse the radon gas into the room's atmosphere. With inappropriate ventilation, concentrations of radon gas can reach unacceptable levels.

Final Word!

Radon gas can be one of the dirty dozen in not only science laboratories, but also other areas of the school and homes. It would certainly be advantageous to work with administrators and supervisors to address this issue and work on a safer environment * for you and your students!

Additional Resources:

EPA Website: http://www.epa.gov/iaq/radon/index.html

EPS * Radon Measurement in School * Revised Edition (EPA402-R-92-014)

National Academy of Sciences (NAS) * Biological Effects of Ionizing Radiation (BEIR) VI Report: “The Health Effects Of Exposure To Indoor Radon”

NAS * Report on Radon in Drinking Water * “Risk Assessment Of Radon In Drinking Water”

National Radon Information Line: 1-800-SOS-RADON (18007677236)

LIVE LONG AND PROSPER WITH SAFETY!

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Dr. Ken Roy
K-12 Director of Science & Safety & authorized OSHA instructor
c/o Glastonbury Public Schools
Glastonbury, CT 06033-3099
Fax 860-652-7275
E-Mail: royk@glastonburyus.org