Metal Bioaccumulation in the Muscle of the Northern Pike (Esox lucius) from Historically Contaminated River and the Estimation of the Human Health Risk

The impact of the long-term historical contamination of the Mrežnica River with textile industry wastewaters on metal/metalloid bioaccumulation in the muscles of the young northern pike (Esox lucius) (0+ to 3+) was evaluated, as well as the association of bioaccumulated metal/metalloid concentrations in the muscle with fish physiology. Increased levels of several elements (As, Bi, Cs, Co, Cu, Zn), bioaccumulated in fish muscle, were occasionally found in front of the former factory, but the obtained metal/metalloid concentrations in muscle were in general either comparable or even lower than in the fish from moderately contaminated freshwaters. Calculated target hazard quotients indicated that the current risk for humans, arising from consumption of the northern pike meat originating from a historically contaminated section of the Mrežnica River, was negligible. The influence of biological factors, especially seasonal physiological changes, on metal/metalloid bioaccumulation was confirmed, indicating the importance of the involvement of these parameters in the freshwater pollution assessment, but also in the estimation of the human health hazard. The increased bioaccumulation of several metals/metalloids in fish muscle at a historically contaminated site pointed to the need for continuous supervision of fish health and biodiversity in freshwaters impacted by currently suspended long-term contamination sources.