Predicting plant uptake of organic chemicals from soil or air using octanol/water and octanol/air partition ratios and a molecular connectivity index
✍ Scribed by Deanna L. Dowdy; Thomas E. McKone
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 104 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0730-7268
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
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~ow~) as predictors of BCRs from the soil matrix into above‐ or below‐ground vegetation tissues. Calculated octanol/air partition coefficient (K~oa~) values are compared with calculated K~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~ow~ and MCI approaches have a similar level of precision for predicting BCRs from soil solution into roots and, among MCI, K~oa~ and K~ow~; K~oa~ is somewhat more precise and valid than MCI and K~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~oa~ values and measured air‐to‐plant BCRs and indicate a need for more experimental measurements from which more accurate models may be developed.