Model applicability in human and environmental risk assessment
Here, we present a mechanistic bioaccumulation model for chemical exchange via air, which is applicable to neutral organic chemicals and various mammals. This model uses chemical- and species-specific inhalation rate constants and exhalation rate con- stants that are estimated based on chemical properties, physiological partition coefficients and species characteristics. The advantage of the model is the relative simplicity and the minimum amount of input- data required, i.e. adult mass of the species, and the octanol–water and air–water partition coefficient of the chemical. We have evaluated the performance of this model for accumulation kinetics of volatile organic compounds in rats, mice and humans. The model produces a fit within a factor of 2–5 from empirical data. This is considered satisfactory for a generic model, as both the external validation data and used model parameters (chemical properties and allometric relationships) are subject to inherent uncertainties. At present, options to evaluate the model for other animal species and for other chemicals were limited and this is an important direction for further research.