title: Uncertainty in octanol-water partition coefficient: implications for risk assessment and remedial costs.
abstract: The assessment of human health and ecological risks at chemically contaminated sites often includesthe use of models to assess chemical transport, fate, and exposure/toxicity. These models require input data on a variety of physical and chemical properties for each compound of concern. Small changes in some of these parameters may result in significant differences in estimated human health or ecological risks and in the extent of required remediation efforts. The octanol-water partition coefficient (Kow) for hydrophobic organic compounds is one such parameter, particularly because it is often used to estimate additional partitioning and bioaccumulation parameters. Unfortunately, there is considerable variability among tabulated Kow values for many compounds of concern. This paper assesses the implications of using various values of Kow to calculate health-protective polychlorinated biphenyl (PCB) sediment quality objectives (SQOs) in a case study using a simplified food chain model and the range of Kow values available from or recommended by the U. S. EPA. For the site and Kow values considered in this study, which are a snapshot of values available in the spring of 2004, the SQOs differ by as much as a factor of 5. This range of SQOs is estimated to correspond to a difference in remediation costs of $48 million.
authors.affiliation: Cambridge Environmental Inc., 58 Charles Street, Cambridge, Massachusetts 02141, USA. linkov@CambridgeEnvironmental.com
authors.forename: Igor
authors.initials: I
authors.lastname: Linkov
authors.forename: Michael R
authors.initials: MR
authors.lastname: Ames
authors.forename: Edmund A C
authors.initials: EA
authors.lastname: Crouch
authors.forename: F Kyle
authors.initials: FK
authors.lastname: Satterstrom
mesh_terms: D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants; D005399:Fishes; D020387:Food Chain; D019015:Geologic Sediments / Q000032:analysis; D006801:Humans; D007700:Kinetics; D008962:Models, Theoretical; D000442:Octanols / Q000032:analysis*; D009930:Organic Chemicals; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012987:Soil / Q000032:analysis; D014481:United States; D014861:Washington; D014867:Water / Q000032:analysis*; D014873:Water Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical
chemical_list: D004785:Environmental Pollutants; D000442:Octanols; D009930:Organic Chemicals; D012987:Soil; D014873:Water Pollutants; D014874:Water Pollutants, Chemical; D014867:Water