Biochemical screening of highly toxic aromatic contaminants in river sediment and comparison of sensitivity of biological model systems

Fractions containing polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofirrans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were extracted from river sediments by various extraction methods. The amount of individual pollutants was determined analytically and data compared with biological assays. These were based on the induction of cytochrome P450 1Al (CYPIA1) after treatment with sediment fraction; in two different biological model systems, a mouse hepatoma cell line Hepa-1 and a chick embryo. In the hepatoma cell culture Hepa-1 significant correlations with analytical results were found for fractions containing PCDD/Fs and planar and mono-ortho-chlorinated PCBs. However for PAH fraction an undesirable decrease of P450 1Al induction was observed in higher concentrations of this fraction. This decrease was not observed in the chick embryo liver microsomes and biological responses towards the PAH fractions correlated with analytical data. Comparative investigations demonstrated that the chicken embryo hepatic microsomes were more sensitive for PAHs, and the hepatoma cell line Hepa-1 for PCDD/Fs and planar and mono-ortho-chlorinated PCBs.