BIOCONCENTRATION OF GASEOUS ORGANIC-CHEMICALS IN PLANT-LEAVES - COMPARISON OF EXPERIMENTAL-DATA WITH MODEL PREDICTIONS

This literature study is performed to support the implementation of tw o models in a risk assessment system for the evaluation of chemicals a nd their risk for human health and the environment (Uniform System for the Evaluation of Substances [USES] 1.0). One of the exposure pathway s for humans and cattle is the uptake of chemicals by plants. In this risk assessment system the transfer of gaseous organic substances from air to plants modeled by Riederer is included. A similar model with a more refined approach, including dilution by growth, is proposed by T rapp and Matthies, which was implemented in the European version of th is risk assessment system (EUSES). In this study both models art evalu ated by comparison with experimental data on leaf/air partition coeffi cients (bioconcentration factors [BCFs]) found in the literature. For herbaceous plants both models give good estimations for the leaf/air p artition coefficient up to 10(7), with deviations for most substances within a factor of Eve. For the azalea and spruce group the fit betwee n experimental BCF values and the calculated model values is less adeq uate. For substances for which Riederer estimates a leaf/air partition coefficient above 10(7), the approach of Trapp and Matthies seems mor e adequate: however, few data were available.