Induction of EROD activity in European eel (Anguilla anguilla) by different polychlorobiphenyls (PCBs)

The present study investigated EROD activity in European eel (Anguilla anguilla) to see if this is a suitable biomarker for PCBs. Time-course and dose-response studies were carried out with PCB-77. Various PCBs were then tested; those chosen have shown induction in previous studies. Aroclor 1254 was included as an example of a commercial PCB mixture. Results showed that EROD activity remains high three weeks after induction by PCB-77; EROD activities increased in a dose dependant manner but increases were not linear. Eels treated with Aroclor 1254 induced much lower EROD activities. The order of induction decreased from 2,3,7,8-TCDD to PCB-77 to PCB-169. PCBs 105, 118 and 153 produced levels of EROD activity close to the controls. The European eel seems to be a sensitive tool as a biomarker for the most toxic PCBs (non-ortho substituted) but has a low response to Aroclor 1254 unlike many other species.