Assessment of the Bioactivity of Creosote-Contaminated Sediment by Liver Biotransformation System of Rainbow Trout

A sediment site in the Lake Jämsänvesi (municipality of Petäjävesi, Finland) contaminated by creosote was investigated to assess the possible ecotoxicological risks it may cause to benthic animals, including ones which may arise due to physical measures in remediating the site. It is suggested that polycyclic aromatic hydrocarbons (PAHs) are bioavailable to fish and other aquatic animals during exposure to contaminated water, sediment, and food. In order to assess toxicological risks of sediment contents to fish, juvenile rainbow trout (Onchorhynchus mykiss) were intraperitoneally dosed with extracts of the creosote-contaminated sediments and their elutriates. This was compared to pristine lake sediment spiked with creosote. Activity of CYP1A1 in trout liver was measured as ethoxyresorufin O-deethylase (EROD). When compared to vechicle controls and the pristine reference sediment (0.9–1.3 pmol/min/mg PMS protein), the extract of creosote-contaminated sediment of Lake Jämsänvesi induced EROD activity up 20–30 times with a dose of 100 mg/kg [total PAHs (mg)/(kg) in fish]. The rise of EROD was associated with increasing levels of PAH metabolites in bile, analyzed as 1-OH pyrene equivalents.