Estimating Grass-Soil Bioconcentration of Munitions Compounds from Molecular Structure

Area of Science:

• Environmental Chemistry
• Plant Physiology
• Toxicology

Background:

• Munitions compounds can contaminate soil and water.
• Understanding their uptake by plants (bioconcentration) is crucial for environmental risk assessment.
• Previous models often require extensive experimental data.

Purpose of the Study:

• To develop and validate a partitioning-based model for estimating munitions compound bioconcentration in grasses.
• To utilize polyparameter linear free energy relationships (pp-LFERs) for predicting partition coefficients.
• To assess the contribution of different partitioning steps to overall plant uptake.

Main Methods:

• A partitioning model was developed using pp-LFERs to estimate partition coefficients.
• Inputs for pp-LFERs were molecular descriptors derived solely from chemical structures.
• The model predicted plant concentrations and was validated against experimental data.

Main Results:

• The model accurately predicted bioconcentration of munitions compounds in grasses.
• A root-mean-square error of 0.429 was achieved in validation.
• Partitioning into the plant cuticle was identified as a dominant factor in bioconcentration.

Conclusions:

• The developed pp-LFERs model effectively estimates munitions compound bioconcentration in plants.
• Molecular structure alone is sufficient input for risk assessment.
• This approach facilitates environmental risk assessment for munitions and related compounds.