Probabilistic assessment factors for human health risk assessment. A practical guide

Abstract

This practical guide was written for the application of probabilistic distributions of default assessment factors in human health risk assessments.RIVM, the National Institute of Public Health and the Environment and TNO, the Netherlands Organisation for Applied Scientific Research developed the use of probabilistic assessment factors as a first step towards further national and international harmonisation.Consensus was reached on the nature of distributions of several human assessment factors.The proposed distributions will be applied in risk assessments of new and existing substances and pesticides prepared at RIVM and TNO.A format for this type of probabilistic risk assessment is also presented in this document.* The whole distribution is increased by one (shifted to the right) since by definition the intraspecies factor cannot be smaller than unity ** Assumes equal heterogeneity in rats and humans *** Based on Slob and Pieters (1998) * These extrapolation steps are incorporated in the combined default distributions.Point estimates are to be used for the other extrapolation steps.* These extrapolation steps are incorporated in the combined default distributions.Point estimates are to be used for the other extrapolation steps.