CORRELATION OF THE EQUILIBRIUM AND KINETICS OF LEAF AIR EXCHANGE OF HYDROPHOBIC ORGANIC-CHEMICALS

A simple fugacity-based model is presented describing the equilibrium and kinetics of uptake by leaves of hydrophobic organic chemicals in the vapor state from the atmosphere. A correlation is suggested for the leaf-air bioconcentration factor as a function of the chemicals' water-air and octanol-air partition coefficients and the leaf properties of air, water, and octanol-equivalent volume fractions. The octanol-air partition coefficient (which can be evaluated from the octanol-water and air-water partition coefficient) is suggested as the key partitioning descriptor for hydrophobic chemicals. A correlation for the leaf clearance rate constant is suggested in terms of two empirical leaf-specific transport parameters and the control-air partition coefficient.