A comparison of model estimates and measurements of PCB levels in soil and produce near New Bedford Harbor

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:191296

Cullen, A ^[1]

---

1. Harvard School of Public Health, Boston, MA (United States). Dept. of Environmental Health

Soil and produce samples collected from 4 areas 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 probability/frequency distributions of predicted levels. The probability/frequency distributions were generated using Monte Carlo simulation and simple partitioning models based on measurements of PCBs in air from a related survey. Although the modeled distributions were associated with broad uncertainty bounds, it was observed that even the lower fractiles exceeded measured levels in most cases. For some cases the models over-predicted the median measurements by more than two orders of magnitude. How does one interpret, use and refine such results and to what extent is over-prediction generally occurring? PCB transport from the sediments and the resulting concentrations in the water column, air, soil and plants are observed to respond to a variety of factors which vary broadly in space and time, such as meteorological and tidal cycles and disturbances. In the past year efforts to remediate the harbor by dredging have altered the system significantly. Thus, to gain insight the authors are repeating the comparison described above. Results reflecting the increased levels of PCBs in air during dredging will be presented along with the results of the original work.

• OSTI ID: 191296
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOLOGICAL ACCUMULATION
COMPARATIVE EVALUATIONS
ENVIRONMENTAL EXPOSURE PATHWAY
ENVIRONMENTAL TRANSPORT
FORECASTING
LAND POLLUTION
MASSACHUSETTS
MATHEMATICAL MODELS
MONITORING
MONTE CARLO METHOD
POLYCHLORINATED BIPHENYLS
REMEDIAL ACTION
US SUPERFUND