Accumulation of dioxins and induction of cytochrome P450 1A4/1A5 enzyme activities in common cormorants from Lake Biwa, Japan: Temporal trends and validation of national regulation on dioxins emission

► Temporal trends of dioxins accumulation in common cormorants from Japan were examined. ► Neither dioxins levels nor CYP1A activities declined clearly during 2001 and 2008. ► We propose a continuous monitoring study on dioxins levels in wildlife from Japan.