University to begin radon testing protocol in April

As part of a new schedule for radon testing, the University in April will begin measuring radon levels in the basement and below-grade levels of all its administrative buildings on campus and all University-owned housing. Testing is expected to take place over the next year, and building occupants will be notified of the assessment schedule for their building in advance of testing.

The Department of Facilities began testing all undergraduate residence halls over the summer in the first part of a two-phase radon assessment of buildings across campus. The dorm testing was completed this month. There were five student residence halls where elevated levels were found in the dorm phase of testing, and they have been remediated. Subsequent testing confirmed that radon levels are well within federal guidelines, so further testing of undergraduate dorms won't be necessary in the immediate future.

University-wide radon testing was last conducted in the 1990s, and the schedule of radon assessment and abatement procedures continuing this spring will become part of a regular cycle of testing to be conducted every 10 years. In addition, the Department of Facilities will continue to test any buildings undergoing major construction.

Radon is a naturally occurring radioactive gas without color, odor or taste that comes from the natural breakdown of uranium in soil, rocks and water, and is commonly found in the ambient air. The U.S. Environmental Protection Agency estimates the average indoor radon level is about 1.3 picoCuries per liter (pCi/L), and has set guidelines that recommend limiting residential levels to 4 pCi/L .

"The University has contracted with environmental health specialists to put abatement measures in place to ensure that all areas fall within the EPA guidelines for radon levels," said Thomas Nyquist, director of the Department of Engineering Facilities. "Remediation of areas with elevated levels includes using exhaust systems to vent the air to the outside, sealing cracks in building foundations, and drilling through concrete foundations to vent the radon gas, which typically moves up through the ground through cracks and other holes in the foundation."

The University initiated the current schedule of air quality testing after a group of students participating in a lab for a physics course notified administrators in May 2007 of elevated levels at their test sites. The students found that levels of radon in the basement library of Forbes College were higher than in the laboratories they used as a baseline for their tests.

The University remediated Forbes College and contracted with radiation specialists working for the Gaithersburg, Md., office of Dade Moeller & Associates, a firm specializing in occupational and environmental health sciences, to develop a procedure for testing all remaining campus spaces in contact with the ground that are occupied for more than two hours per week.

Tested areas typically will not include stairways, storage rooms, closets, equipment rooms or buildings undergoing renovation, but do include basement common areas in frequent use. In testing for elevated radon levels in the campus' residence halls, the University measured air quality in offices, student rooms, kitchens, laundry areas, computer clusters, music practice rooms, mail areas, bathrooms, and recreational and other social spaces.

Members of the campus community will receive notices informing them of testing dates and guidelines for testing, including requests that the charcoal canisters that measure air quality not be disturbed. Metal canisters -- about the size of a shoe polish tin -- will be placed in rooms for three to five days and then removed for analysis. Results of the testing, including possible mitigation procedures, will be communicated to occupants of the tested area after results are analyzed.

Results of air quality tests of the dorms tested in the first phase of campus-wide testing show that abatement efforts have brought radon levels within EPA guidelines. Among all the residence halls on campus, four were identified as having a small number of rooms with slightly elevated levels of radon, and one was identified as having some areas with greater elevations of radon.

In addition to confirmed elevated levels in basement areas of Forbes College in May, further tests beginning over the summer detected radon concentrations ranging from 5.1 to 9.3 picoCuries per liter (pCi/L) in a few rooms in the lowest level of the upperclass dorm Henry Hall; 4.6 pCi/L in one lower-level room in Blair Hall in the Mathey College four-year residential complex; and 5.2 pCi/L in a bathroom at 2 Dickinson St., an upperclass residence across from campus. These levels were mitigated before students returned to campus to start the academic year, bringing all levels within EPA guidelines.

The continued dorm tests ending this month detected radon concentrations at Bloomberg Hall ranging from 1 to 11.0 pCi/L in the west wing's third entryway, and concentrations in the west wing's 30s-numbered rooms, and concentrations in the east wing's 50s, 60s and 70s rooms ranging -- at the lowest and highest levels -- from a room with a level of 1.4 pCi/L to a room measuring 205 pCi/L. The greater elevations in Bloomberg were found in basement areas used as music practice rooms, where users of the space had much lower periods of exposure than outlined by EPA guidelines, which are based on persistent exposure in a residential environment.

"To provide a sense of perspective, an individual would need to spend nine hours per week based on the average of concentrations detected in the basement of the east wing of Bloomberg to have the same exposure as a person living for a week in a house with radon levels at the EPA guidance level of 4 picoCuries per liter," said University Health Physicist Sue Dupre of the Office of Environmental Health and Safety.

Affected areas of Bloomberg were closed over Spring Break while testing and remediation were completed. Remediation has brought radon concentrations down to levels ranging from 0 to 0.5 pCi/L -- well within EPA guidelines.

Tests were conducted in basement and below-grade levels, in accordance with EPA guidelines. Sample testing of first-floor rooms verified that elevated radon levels could not be found in above-ground areas adjacent to basement levels.

According to Dupre, there is no evidence of significant additional long-term health risk from short-term exposure to the elevated levels found in the dormitory phase of radon testing. Princeton is among many areas throughout the region that sit on a geologic formation called the Reading Prong, which underlies southeastern Pennsylvania and part of New Jersey, and has an elevated uranium content.

"The EPA bases its risk assessments on lifetime exposure," Dupre said. "While EHS calculated that the additional lifetime risk to a student who spent an academic year in a room at the highest radon level detected in the dorm phase of testing would be only marginally greater than an individual exposed to the EPA recommended level of 4 pCi/L over a lifetime, the University is committed to reducing any levels detected over the recommended point."

Further information will be conveyed to occupants of individual buildings when buildings are scheduled for testing in the second phase of the radon assessment. Occupants who have additional questions in the interim may visit the Department of Facilities information website. Students with health questions related to the testing of the undergraduate dorms also may call the Office of Environmental Health and Safety (609) 258-5294 or e-mail