Building materials that included asbestos, lead, mercury, and polychlorinated biphenyls (PCBs) are generally believed to have been phased out and banned and are often not considered when analyzing potential occupational exposures. Some of these materials have not actually been banned, and even those that have been may still be present in existing building materials and equipment. Occupational exposures related to the presence of these materials and contact with them during repair, renovation, and routine operational activities is often poorly characterized and misunderstood. Further, governmental agencies involved in regulating these materials may apply differing rules and regulations that vary based on the material, its condition, or the specific activity being performed.
Between 2009 and 2010 we worked with a large municipal waste-water treatment bureau (the Bureau) to develop a strategy to characterize and manage exposures to these "legacy" materials. This bureau operates more than 20 waste-water treatment plants varying in age from 25 to 100 years. Each treatment plant consists of multiple buildings, miles of pipe, and an array of mechanical equipment. We were approached by the bureau after an initial exposure assessment and sampling strategy developed by the bureau was deemed to be too costly to implement.
The initial strategy consisted of extensive bulk sampling in an effort to create a database of the location of all materials containing asbestos, lead, mercury or PCBs (collectively the contaminants of concern or COCs) in the facilities. This initial plan called for the sampling of virtually all painted surfaces and suspected asbestos-containing materials regardless of condition or likelihood of contact or disturbance. This plan relied upon the assumption that the presence of these materials alone presents unacceptable risk to workers; however, the strategy did not assess the condition of materials and the activities performed on them, which are much more accurate indicators of exposure risk. Further, this strategy did not account for the fact that new products could still contain these COCs, nor did it address any new contaminants of concern that might be part of the new products.