Influence of distributional shape of substance parameters on exposure model output.
Uncertainty of environmental concentrations is calculated with the regional multimedia exposure model of EUSES 1.0 by considering probability input distributions for aqueous solubility, vapor pressure, and octanol-water partition coefficient, K(ow). Only reliable experimentally determined data are selected from available literature for eight reference chemicals representing a wide substance property spectrum. Monte Carlo simulations are performed with uniform, triangular, and log-normal input distributions to assess the influence of the choice of input distribution type on the predicted concentration distributions. The impact of input distribution shapes on output variance exceeds the effect on the output mean by one order of magnitude. Both are affected by influence and uncertainty (i.e., variance) of the input variable as well. Distributional shape has no influence when the sensitivity function of the respective parameter is perfectly linear. For nonlinear relationships, overlap of probability mass of input distribution with influential ranges of the parameter space is important. Differences in computed output distribution are greatest when input distributions differ in the most influential parameter range.
Lessmann
Kai
K
Institute of Environmental Systems Research, University of Osnabrück, 49069 Osnabrück, Germany.
Beyer
Andreas
A
Klasmeier
Jörg
J
Matthies
Michael
M
D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000008:administration & dosage / Q000633:toxicity; D006801:Humans; D015233:Models, Statistical; D009010:Monte Carlo Method; D018570:Risk Assessment; D012995:Solubility
D004785:Environmental Pollutants