PCB Risks in Fires, Accidents, and the Printing Industry: Part B Risk Estimation and Application to PCB Fires and Printing Inks
Strategies in the Workplace
Risk estimation and its applicability to groups with past exposures to polychlorinated biphenyls (1336363) (PCBs) are discussed. The principles of risk assessment are reviewed. Risk assessment can be considered to consist of four steps: identifying and evaluating the hazard, evaluating the dose effect relation, identifying the conditions of exposure, and assessing the probability of a health hazard. It is noted that risk assessment is usually applied to future and potential exposures; however, it can be extended to cover past exposures. In the case of past PCB exposure, the approach may involve selecting biological markers, such as serum PCB concentrations or fat dioxin content, which can be used to estimate absorbed dose. Examples of applying risk assessment to past PCB exposures are given. These include a PCB fire in an office building in Binghampton, New York, a transformer fire in San Francisco, California, and the exposure of pressmen to a newspaper ink that contained 3,3'-dichlorobiphenyl (2050671). Risk assessment using data from the Binghampton fire estimated that the risk of an additional case of cancer was 1 per million. In the case of the transformer fire, it was estimated that a large proportion of the individuals exposed to the fire probably had significant exposure to PCBs and polychlorinated dibenzofurans and could incur an increased risk of long term adverse health effects in the future. The latency period for the health effects, however, was difficult to predict. In the PCB containing ink, based on the PCB content of fat biopsies, it was predicted that the exposed pressmen would not have a significantly increased risk of developing long term adverse health effects.