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Comparison of three fish bioaccumulation models for ecological and human risk assessment and validation with field data. Hana Smítková, Jan Hendriks, Mark Huijbregts. Bioaccumulation models are integrated: because of financial, practical and ethical constrains
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Comparison of three fish bioaccumulation models for ecological and human risk assessment and validation with field data Hana Smítková, Jan Hendriks, Mark Huijbregts
Bioaccumulation models are integrated: • because of financial, practical and ethical constrains • for estimating environmental transport • for estimating human exposure • like tools that can be used for: • rapid and • quantitative assessment of the hazards and risks organic substances • Fish bioaccumulation models, which were compared: • human exposure: • EUSES • CalTOX • environmental exposure: • OMEGA
The concentration in fish can be calculated: • Q represents: • the bioconcentration factor for fish (BCFfish) • in models EUSES and CalTOX • the bioaccumulation factor (BAFfish) • in model OMEGA • CalTOX • seven compartment multimedia human exposure model • is a risk assessment model that integrates a multimedia environmental fate model with a multiple pathway exposure • the bioconcentration factor of fish in CalTOX is taken from Mackay (1982):
EUSES • European Union System for the Evaluation of Substances, version 2.0 • is designed to facilitate the risk assessment of a broad range of substances • is based on the EU Technical Guidance documents • if log Kow ≤ 6 then: • if log Kow > 6 then:
OMEGA • is based on classical fugacity theory • is based for accumulation kinetics of organic substances as a function: • of the octanol-water partition ratio • of the chemical • of the weight, • of the lipid content, • of trophic level of the species • the basic equation for OMEGA is given by: • in case of steady state, this gives:
Scheme of fresh water and marine food chain applied in this comparison
all models are virtually similar up to a log Kow of 6 • for substances with a log Kow higher than 6 the curve of model EUSES decreases parabolic • OMEGA bioaccumulation outcomes approximately show a linear increase • the OMEGA-outcomes are close to the fish bioconcentration outcomes of the model CalTOX
To compare the fish bioaccumulation model with measured field data, the organism-suspended matter concentration ratio was calculated by:
comparison of three models: • EUSES • CalTOX • OMEGA - primary carnivores (5% lipid content) • with chemicals compounds from: • ■ chlorobiocides • ● chlorobiphenyls • ▲ halobenzenes • for fresh water fish Rutilus rutilus
comparison of three models: • EUSES • CalTOX • OMEGA - primary carnivores (5% lipid content) • with chemicals compounds from: • ●chlorobiphenyls • + haloalkanes • x phenylethers • for marine fishes Ammodytes species, Chasmichthys gulosus, Clupeidae, Clupea harengus, Eutriglia gurnardus, Osmerus eperlanus and Pleuronectes platessa
comparison of three models: • EUSES • CalTOX • OMEGA - lean secondary carnivores (5% lipid content) • with chemicals compounds from: • ● chlorobiphenyls • + haloalkanes • x phenylethers • for marine fishes Gadus morhua, Merlangius merlangus, Platichthys flesus, Pollachius virens, Solea solea and Trisopterus luscus
comparison of three models: • EUSES • CalTOX • OMEGA - fat secondary carnivores (20% lipid content) • OMEGA - fat secondary carnivores(20% lipid content) depends on BCF from water only • with chemicals compounds from: • ■ chlorobiocides • ● chlorobiphenyls • ▲ halobenzenes • ♦ nitrobenzenes • for fresh water fish with 20% lipid content Anguilla anguilla
Conclusion • All models are similar up to a log Kow 6. • For more hydrophobic compounds (log Kow > 6), the models EUSES and OMEGA, based on water exposure only, decrease parabolic. • OMEGA curves with food as an additional exposure route are almost linear. • These OMEGA curves are very close to those of the model CalTOX. • The comparison to field data show that assimilation from food needs to be incorporated. • Incorporation of lipid content improves exposure assessment for human and ecological risks substantially, because lipid content of fish is also very important. • Empirical organism-suspended matter concentration ratios do not confirm the difference between primary and secondary carnivores.