Predicting plant uptake of organic chemicals from soil or air using octanol/water and octanol/air partition ratios and a molecular connectivity index
- Univ. of California, Davis, CA (United States). Dept. of Environmental Toxicology
- Univ. of California, Berkeley, CA (United States). School of Public Health
A bioconcentration ratio (BCR) represents the ratio of the concentration of a chemical found in an exposed biological system, such as a plant or fish, to the concentration in the exposure medium (water, soil, or air). A comparison is made of the precision and accuracy of the molecular connectivity index (MCI) and the octanol/water partition coefficient (K{sub ow}) as predictors of BCRs from the soil matrix into above- or below-ground vegetation tissues. Calculated octanol/air partition coefficient (K{sub oa}) values are compared with calculated K{sub ow} and MCI values as predictors of measured air-to-plant BCRs. Based on a statistical evaluation of explained variance, residual error, and cross-validation, this evaluation reveals that the MCI provides higher precision, greater ease of use, and a more cost-effective method for predicting the potential bioconcentration of a chemical from soil into above-ground vegetation. Statistical analyses of the various methods reveal that both the K{sub ow} and MCI approaches have a similar level of precision for predicting BCRs from soil solution into roots and, among MCI, K{sub oa} and K{sub ow}; K{sub oa} is somewhat more precise and valid than MCI and K{sub ow} for estimating uptake, but all have limited accuracy as bioconcentration predictors. These latter results are derived mainly from the paucity of both reliable K{sub oa} values and measured air-to-plant BCRs and indicate a need for more experimental measurements from which more accurate models may be developed.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 561949
- Journal Information:
- Environmental Toxicology and Chemistry, Vol. 16, Issue 12; Other Information: PBD: Dec 1997
- Country of Publication:
- United States
- Language:
- English
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