Comments of the General Electric Company on the U.s. Environmental Protection Agency’s Human Health Risk Assessment for the Housatonic River Site – Rest of River

presenting additional information, views, and analyses that may help to refine the HHRA to be more reflective of the potential for exposures and risks due to polychlorinated biphenyls (PCBs) in the Rest of River portion of the Housatonic River and its floodplain. These comments generally follow the structure of the Peer Review Charge developed by EPA. As such, they first discuss each of the three risk assessments in the HHRA – the Direct Contact Assessment, the Fish and Waterfowl Consumption Assessment, and the Agricultural Products Consumption Assessment – focusing primarily on the inputs affecting exposure. They then discuss more general issues, including the approaches and values used in the HHRA to assess toxicity, which are critical issues affecting all three risk assessments. (The following sections of this Executive Summary reference in parentheses the corresponding sections of the comments where the points are discussed in more detail.) At the outset, it should be noted that, although the HHRA relies on hypothetical exposure and risk estimates, there are some actual empirical data that relate to exposures and health risks in the Housatonic River area. For example, in 2002, GE consultants conducted an intensive Floodplain User Survey of recreational use of the floodplain areas in the most contaminated part of the floodplain (the stretch between the East/West Branch Confluence and Woods Pond) (TER, 2003). Much of the floodplain in this stretch (apart from residential properties) consists of wetlands or backwaters and/or dense vegetation, with only certain specific areas, such as trails and other recreational areas, more accessible to human use. Consistent with these physical characteristics, the survey showed that the majority of floodplain areas receive little or no recreational use and that only a relatively few areas have regular recreational use. In addition, data collected by the Massachusetts Department of Public Health (MADPH, 1997) on PCB levels in blood collected from individuals in the area who were identified as having a high potential for PCB exposure showed that the blood PCB levels in non-occupationally exposed individuals in this survey were, in fact, within the normal background range. Further, the latest cancer incidence data reported by ATSDR (2002) for the local area show that cancer i rates for the towns adjacent to the most contaminated portion of the river are not elevated and not associated with areas having high PCB concentrations. These site-specific real-world data provide an important backdrop for evaluating the hypothetical assumptions …