H
"Any change in construction around the perimeter
of a building or in ventilation should probably
trigger a new test in radon levels because it will
probably make them worse," he said. "And if you
don't test, you don't know."
There are two ways to test for radon in schools that the EPA recommends.
Short-term testing uses devices that absorb radon over the course of two to
90 days. Short-term measurements may utilize activated charcoal devices,
alpha track detectors or other monitors. Long-term testing remains in place
for more than 90 days and is usually conducted over the course of an entire
school year. The longer-term testing devices give a more accurate
representation of radon levels. The EPA recommends that when initial tests
are conducted with short-term devices, that a long-term test is conducted
when radon levels are at or above four pCi/L.
For buildings that are "slab-on-grade" design, the EPA recommends
measuring only frequently occupied rooms in contact with the ground.
Rooms above crawlspaces should be tested, as well as all frequently
occupied rooms in buildings with basements, and frequently occupied
basements rooms. The EPA recommends testing under closed conditions
after 12 hours of closure and in colder months when heating and cooling
systems are operating normally.
The EPA and other major and international scientific organizations have
concluded that radon is a human carcinogen and a serious environmental
health problem. Because radon levels may vary from room to room, the EPA
recommends schools test all "frequently occupied rooms in contact with the
ground," according to the EPA's "Radon Measurement in Schools" guidelines.
"Each frequently occupied room that is in contact with the ground should be
measured because adjacent rooms can have significantly different levels of
radon."
The EPA first began investigating radon in schools in 1988, when a study in
Fairfax County, Virginia, was conducted and used to develop initial
guidelines. In the subsequent two years, the EPA conducted a nationwide
study, which resulted in the action level of 4 pCi/L.
The EPA later conducted a National School Radon Survey, a statistical
representation of levels of radon in schools at the national level, but not the
state or local level. The results showed a widespread contamination of radon
in schools, with nearly one in five schools having at least one frequently
occupied room with the ground with short-term radon levels above four
pCiL.
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