KINGSTON, RI -- March 9, 2001 -- The initial results of the Phase II sampling of the Chafee Social Science Center show materials associated with window assembly and materials used in the assembly of the unit room ventilators located under each window as potential sources of polychlorinated biphenyls (PCBs).
The goal of this phase was to quantify the level of PCBs in a variety of building materials that might be the source of the PCB residues found in the building during the Phase I sampling effort.
On Feb. 16 and 17, Environmental Health and Engineering (EH&E), the Newton, Mass. consulting firm hired by URI, collected more than 50 samples of building materials and additional dust samples from various locations within Chafee to determine PCB content.
Gasket materials associated with the windows and caulking material between the masonry and the window frames tested the highest for PCB levels. PCBs represent three percent of the caulking material. The other product that tested high for PCBs is a glazing compound, a rubber sealant that seals the pane of glass to the windowsill.
PCBs in much lower concentrations were found in the unit ventilators sampled, specifically in the black polyurethane foam and in the front shield mastic (glue used to seal the insulation to the front panel).
The Phase II results indicate levels of PCBs found within materials, unlike the air, dust or wipe sampling conducted during Phase I.
The PCB levels in Phase II were found in materials from the high-rise and in the two-story, low-rise portions of the building. The lecture halls in the building have no windows.
"The results show compelling evidence of possible source materials," said J. Vernon Wyman, assistant vice president for business services. "These findings, however, need to undergo additional scrutiny and verification," he added.
"The window systems themselves contain materials with PCBs in them," said Kevin Coghlan, technical director of EH&E. "These findings do suggest multiple sources of PCBs," he added.
"The caulking compound, applied to the masonry around the opening cut for the aluminum window frame, is not accessible," said Coghlan.
"You cant touch it, you cant ingest it, and it was difficult to get at it in order to provide the samples, " said Wyman, adding, however, "it does suggest this material has been present since the date of construction of the building in 1972."
Prior to the Phase II sampling, EH&E reviewed the professional literature regarding PCB containing materials as well as the architectural plans and building specifications for Chafee. This review identified a number of building materials added during the manufacturing process that might contain PCBs. The elevated levels found were consistent with those measured in products that have been associated with indoor residues of PCBs and described in the professional literature.
The findings on the building materials do not change any of the results from the Phase I testing in which levels of PCBs were assessed in air samples, dust in the room unit ventilators, and samples wiped from desks and other surfaces in the physical work spaces.
In the Phase I sampling, the wipe samples showed no detectable levels of PCBs in any of the four lecture halls or the eight-story office tower. Two of three wipe samples in the two-story low-rise portion of the building showed no detectable levels of PCBs. The third sample was slightly above the limit of detection.
At the time, Coghlan said the results of the wipe samples were encouraging because they suggested surfaces that people touch were not widely contaminated.
However, Phase I findings from tests on exterior window gaskets on the fifth floor showed PCB levels of 4.2 parts per million and 30 parts per million. Coghlan theorized at the time that these gaskets could be one source of the PCBs measured in dust and air.
Dust in the unit ventilators from all of the floors in the Chafee office tower was tested, and detectable concentrations ranged from 8.2 to 81 parts per million. In the Phase I investigation, the highest PCB concentration was measured in ventilator dust from the first floor at 81 parts per million (ppm). While there is a federal OSHA standard for air samples, there is no similar standard for the material found in dust from the ventilators.
The air samples collected in the Phase I investigation from the lobby, lecture halls, and the low-rise section of the building did not have detectable levels of PCBs. The second floor of the high rise also showed no detectable levels of the compound. However, PCBs found in air samples from the fourth floor of the high-rise ranged from approximately 0.1 microgram to almost 0.4 micrograms per cubic meter of air.
While those were the highest levels of the compound detected in any of the air samples collected, they are still well below the conservative recommendation by the National Institute of Occupational Safety and Health of 1.0 microgram per cubic meter of air.
The Phase II portion of the investigation also included an assessment of the air flow and air transfer dynamics of the high rise section of the building. Measurements were taken on each floor of the high rise. EH&E examined the airflow associated with the HVAC ventilation system in the building to determine the release of potential suspect materials as well as potential exposure pathways to better understand the Phase I sampling results.
The highest PCB results were measured in an electric motor capacitor and a lighting ballast. Both were in good condition. The PCBs are sealed in these products and cannot readily enter the environment unless they are damaged. They are not considered possible sources, unless a ballast catches fire or a capacitor leaks. There was no evidence of either fire or leaks.
The next step is to verify that the PCB profile in the suspect materials matches the PCB profile of the dust. This information can then be used to develop the cleanup protocol and remediation guidelines and assist in the establishment of clean-up goals.
Samples of gaskets, caulking and other materials (glazing compound, mastic, and foam) that tested high for PCBs will be analyzed further at a North Carolina lab to measure the individual constituents (congeners) to determine specific matches, if any, with the PCBs found in dust. Ten dust samples (five from the high-rise and five from the two-story, low-rise and lecture halls) will also be sent to the lab for PCB, dioxin, and furan congener analysis. It will take about three weeks for this congener analysis.
The information can also be used to better characterize the potential exposures to the occupants and may also be used to refine the epidemiological and medical assessment that is currently under development.
For a detailed listing of the Phase II testing results, see the Chafee web page, accessible from the URI home page at www.uri.edu.
For information: Linda A. Acciardo, (401)-874-2116