These components had been used.

Caulking found to end up being unrecognized way to obtain PCB contamination Environmental health researchers at Harvard School of Public Health have determined caulking and sealing materials as an unrecognized and perhaps widespread way to obtain polychlorinated biphenyl contamination in schools and buildings constructed in the 1960s and 1970s. They conclude a survey of masonry structures from that period is essential to determine where in the U.S . These components had been used, and that caulking ought to be routinely analyzed for PCBs and handled appropriately to lessen potentially significant health threats.