Soil Plant and plant mammal transfer factors

In order to assess the lifetime hazard of ingestion exposure of man to new substances, the RIVM Assessment System for New Substances links environmental concentrations in water and soil to human exposure applying transfer factors. This report discusses indirect human exposure to new substances via consumption of fruits, vegetables, grains, meat and dairy products. A limited validation study of the RIVM Assessment System for New Substances had previously shown that this part of the needed further study with regard to the estimation of transfer factors. On the basis of an evaluation of recent research in this area, the present report proposes what is considered to be an improvement of the RIVM Assessment System for New Substances. Being aware of a persisting high degree of uncertainty in the model estimate, it is recommended to use the biotransfer factor correlations with Kow as determined by Travis & Arms (1988) to estimate the concentration of a substance in meat and dairyproducts. Concerning the uptake of chemicals in plants from soil, it is suggested to estimate the stem concentration factor from the Kow using the extrapolation method based on the experimental work of Briggs et al. (1982, 1983).