Citing findings that one in five classrooms may have elevated radon levels and that children’s cancer risk from the radioactive gas is greater than that of adults, the head of the Environmental Protection Agency last week recommended that all schools test for radon and take steps to deal with it.
The study suggests, agency officials said, that the radioactive gas may be at least as prevalent in schools nationwide as in homes and may be a greater threat to children than asbestos in schools.
“Based on measurements taken in 3,000 schoolrooms in 16 states, it appears that elevated levels of radon gas can be found in schools throughout the United States,” said epa Administrator William K. Reilly.
Mr. Reilly said the preliminary epa data showed radon concentrations above 4 picocuries per liter of air (pCi/L), the agency’s recommended “action level” for undertaking remediation efforts, in 54 percent of the 130 schools tested and 19 percent of the classrooms.
“This finding is particularly troublesome because of the nature of the radon risk, and the potential vulnerability of children exposed to it,” he said. “Therefore, I am recommending that schools nationwide be tested for radon, and that schools prepare to take remedial actions depending on the levels of radon found.”
Mr. Reilly’s remarks represented a significantly stronger statement than that contained in epa guidelines for radon testing and remediation, also released last week.
“I wanted to make this announcement personally,” the official said, “because it is important that school administrators nationwide understand both the seriousness of the risk and the relative simplicity of testing for and fixing the problem.”
He cautioned that the epa did not randomly select the elementary and high schools sampled, and that many of the schools may have been tested specifically because they were believed to have high radon levels.
But he added that “we believe elevated levels of radon may be as prevalent in schools as they are in homes” and that “the risk to children is disproportionately higher than it is to adults.”
Three percent of classrooms tested in the epa study had concentrations above 20 pCi/L, and one school had levels as high as 136 pCi/L, the level above which uranium miners are warned to wear respirators.
Richard J. Guimond, director of the epa’s office of radiation programs, estimated that 10 percent of schools nationwide may have radon levels above the action level. Lifelong exposure to that level, he noted, creates a risk of lung cancer equal to smoking a half-pack of cigarettes a day.
Mr. Reilly said he did not yet have enough information to determine where the highest radon levels are geographically. But he said his agency would undertake more studies to address the question later this year.
Mr. Reilly said no federal funding would be available for radon testing or remediation. But the costs of testing are relatively low, he noted, and “if problems are are found, they can be fixed, in most cases, with relatively simple, inexpensive steps like better ventilation and better maintenance.”
The guidelines reflect the concern of agency officials that the methods commonly used to test homes for radon may not yield accurate readings for schools.
The document outlines the advantages and disadvantages of using the two most common radon detectors, offers protocols for conducting the tests, and cites methods for reducing radon levels.
Last year, the agency and federal health officials recommended that all homeowners test their houses for radon, an odorless, tasteless, and colorless radioactive gas that seeps into buildings through their foundations. The federal health advisory did not apply to schools.
The new school guidelines draw on the results of a study done by the agency last year on school radon testing. It found that, unlike homes, schools may contain significantly different amounts of radon in rooms on the same level.
It also found that concentrations of the gas were lower during classroom hours than on the weekend, when most schools do their testing, and that schools in the same general area can have significantly different radon levels.
Reflecting these findings, the new document recommends that measurements be taken in all frequently used rooms on and below the ground level and every 2,000 square feet in schools with an open-plan layout.
The document also recommends that the measurements be taken during the colder months because closed doors and windows tend to draw radon indoors and will produce the highest readings--or the “worst-case” condition.
School officials may want to use a relatively inexpensive two- or seven-day charcoal canister, the document states, when they need quick results. The canisters, it advises, should be used over a weekend, when students and staff are less likely to disturb them.
The major disadvantage of this method, the document notes, is that readings tend to be less accurate and may be strongly affected by the weather or the ventilation system.
School officials may also choose to use three-month “alpha-track detectors,” which contain plastic strips that are altered by the energy released by decaying radon, the document says.
The guidelines note that using this method may be “advantageous for school officials who believe they may be pressured into taking corrective action upon finding elevated radon levels without conducting confirmatory measurements.”
School officials should retest any rooms that are found to have more than 4 pCi/L before undertaking any mitigation efforts, the report states. A picocurie represents one-trillionth of a curie, the standard measuring unit of radioactivity.
If the results of a second test confirm that there are levels exceeding 20 pCi/L in a school, the guidelines say that officials should take action “within several weeks.”
Such actions become more pressing if readings are greater than 100 pCi/L. At this level, the document states, educators should consult with health officials to determine if “temporary relocation is appropriate until the levels can be reduced.”
Schools that have tests that confirm readings between 4 and 20 pCi/L should take action “within several months.” And schools with confirmed readings below the action level should consider mitigation efforts on a “case-by-case” basis, the document states.
School officials can request copies of “Radon Measurements in Schools” from their regional epa office.
