Environmental health researchers at Harvard School of Public Health have identified caulking and sealing materials as an unrecognized and possibly widespread source of polychlorinated biphenyl (PCB) contamination in schools and buildings constructed in the 1960s and 1970s.
They conclude that a survey of masonry buildings from that era is necessary to determine where in the U.S. these materials had been used, and that caulking should be routinely analyzed for PCBs and managed appropriately to reduce potentially significant health risks.
The study is published in the July 2004 issue of Environmental Health Perspectives.
PCBs are a set of persistent organic chemicals that are known carcinogens and that have significant toxic effects on the immune system, reproductive system, nervous system and endocrine system. Production of PCBs was halted in the U.S. in 1977, but they persist in the environment. Although the principal use of PCBs was in “closed systems” such as electrical transformers, capacitors and other equipment where the PCBs were encased, they were also used in a range of “open system” products, including building materials.
HSPH researchers led by Robert Herrick, Senior Lecturer on Industrial Hygiene in the Department of Environmental Health, carried out an investigation of 24 buildings in the Greater Boston Area. The investigation revealed that one-third of the buildings contained caulking materials with PCB content exceeding U.S. Environmental Protection Agency standards of 50 parts per million, in some cases containing nearly 1,000 times the standard. The buildings where elevated PCB levels in caulking were found included schools, university buildings and other public buildings.
The investigation was prompted by studies done in Finland and by the recent case of a University of Rhode Island building that was found to be contaminated by caulking material containing PCB concentrations 600 times higher than the EPA limit and which resulted in an EPA-mandated cleanup program.
Studies in Finland have correlated PCB content in caulking with PCB content in the air and in the blood of construction workers handling these materials during renovation work. A German study found elevated blood levels of PCBs in teachers working in school buildings with contaminated caulking. Finland has gone so far as to remove these caulking materials from all buildings in the country, and Sweden is preparing rules for a similar abatement.