Update of risk assessment models for the indirect human exposure
Herziening van risicobeoordelingsmodellen voor de indirecte humane blootstelling
26 May 2012, PDF |
53 pages |
Rikken MGJ, Lijzen JPA
RIVM Report 601516011
This report describes the research into the methodology of the indirect human exposure models using two risk assessment tools, EUSES and CSOIL. Alternatives are proposed to the methodology of the indirect human exposure models, considering that their validity often remains unclear. The current plant model proved to function as an appropriate exposure route from air and soil to crops. However, improvements such as adding the particle-bound transport to leaves and using separate parameters for roots and leaves are recommended. The two equations describing the indirect exposure via fish seem sufficiently valid. Nevertheless, measured data is uncertain and the equation for hydrophobic substances leaves room for improvement. Large uncertainties for meat and milk are to be expected in the model, especially for hydrophobic chemicals. The method estimating the purification factors for the ingestion of drinking water can be seen as being rough and near worst case in its application. This method must also be updated, preferably with more European experimental data. The ingestion of soil should also include the ingestion of house dust, because part of this dust originates in the soil. In addition to the mentioned improvements, this report proposes further research for the different exposure routes.