A Comparison of Model Estimates and Measurements of PCB Levels in Soil and Produce Near New Bedford Harbor. A. Cullen, University of Washington, Graduate School of Public Affairs, mailbox 353055, Seattle, WA, 98195-3055
Soil and produce samples collected from 4 locations in the vicinity of the New Bedford Harbor Superfund site were analyzed for 55 individual PCB congeners as part of a study of the transport of PCBs from contaminated harbor sediments to environmental media with which humans come into contact. Soil and produce were collected from farms and backyard gardens both upwind and downwind of the contaminated regions of the harbor. Measured PCB levels in soil and produce were compared to levels predicted by environmental fate model simulations. Probability/frequency distributions representing concentrations in environmental media were generated using Monte Carlo simulation and simple partitioning models based on measurements of PCBs in air from a related study. The environmental fate models overpredicted the median measurements by an order of magnitude or more in some cases. Although the modeled PCB concentration distributions were associated with broad uncertainty bounds, it was observed that even their lower fractiles exceeded the concentration measurements in most cases.