Evaluating the coherence between environmental quality objectives and the acceptable or tolerable daily intake.
Environmental quality objectives (EQOs) for surface water, soil, air, drinking water, and food products are often derived independently. This may result in incoherent EQOs. A set of EQOs is called incoherent if simultaneous exposure to all media which are polluted up to their EQO results in the acceptable or tolerable daily intake (ADI or TDI) being exceeded. This paper outlines an integrated human exposure and uptake model (NORMTOX) which was developed to test the coherence of EQOs. NORMTOX predicts lifetime-averaged daily uptake levels of contaminants and compares these with acceptable or tolerable daily uptake levels. The model deals with variability and uncertainty in put data by using the Monte Carlo simulation technique. The model was applied to test the coherence of Dutch EQOs for benzene, lead, and lindane. The EQOs of these substances turned out to be coherent with probabilities of 100, 23, and 0%, respectively. The variance in the coherence indicators results from interpersonal variability in exposure, consumption, and uptake patterns and from uncertainty in input data due to a lack of knowledge. To prevent incoherent EQOs in the future, induction of a procedure for coherence testing and EQO adjustment is suggested.
Department of Environmental Studies, University of Nijmegen, The Netherlands.
A M
AM
Ragas
M A
MA
Huijbregts
D004781:Environmental Exposure / Q000592:standards*; D004785:Environmental Pollutants / Q000592:standards*; D005506:Food Contamination; D006801:Humans; D009010:Monte Carlo Method; D011634:Public Health / Q000592:standards; D012016:Reference Values; D014881:Water Supply
D004785:Environmental Pollutants