Assessment of combined effects of mixtures of contaminants in the fish (Danio rerio) embryo test(178621)

The North Sea and coastal areas of Norway are polluted by compounds originating from multiple sources on land, from offshore installations, maritime vessels and long range atmospheric transport. The identity of these pollutants and their sources are often unknown, but it is well documented that various halogenated compounds (HC), polycyclic aromatic hydrocarbons (PAHs), antifouling compounds, pesticides, industrial chemicals, heavy metals, pharmaceuticals and personal care products (PPCPs) are among the m ost abundantly distributed pollutants in the marine environment. There is little doubt that these chemicals exist as complex mixtures in the recipient and may consequently cause effects through combination toxicity (mixture toxicity). The two most widel y used modelling approaches, concentration addition and independent action, have proved to be good estimates for the combined effect of mixtures in several in vitro studies. Several in vivo studies have also been conducted with various model prediction re sults. More research on combined effect of mixtures on higher organisatorial level is needed to assess the applicability of these models in risk assessment. Regarding the aim to reduce the number of animals used in research, the fish (Danio rerio) embryo test is a good alternative to in vivo fish studies. Assessment of the acute toxicity of combined effect of mixtures in the fish embryo in combination with microarray studies will expand the knowledge of the combined effect of mixtures on higher organisato rial level.