Fish tissues contamination with some metals (Fe, Mn, Zn, Pb, Cu, Co, Ni, Cr, Cd) from the lower Nitra river

Abstract

In this study, the heavy metal (Fe, Mn, Zn, pb, Cu, Co, Ni, Cr, Cd) contamination of selected fish tissues (muscle, liver and kidney) was determined. A total of 56 fish individuals, belonging to five species (Chub – Leuciscus cephalus, Common carp – Cyprinus carpio, Prussian carp – Carassius auratus, Roach – Rutilus rutilus, and Wels catfish – Silurus glanis) were collected from the river Nitra at 16.4th – 21.6th river kilometres (in the area of Nové Zámky) in September 2004 using an electrofishing technique. Obtained samples of fish muscle, liver and kidney were analyzed by an atomic absorption spectrophotometer (AAS) Pye Unicam SP9. The concentrations of metals (in mg.kg-1 wet weight basis) in analyzed tissues ranged as follows: muscle: Fe 3.70–21.10, Mn 0.27–1.50, Zn 3.72–42.82, Pb 0.08–34.59, Cu 0.26–1.82, Co 0.06–0.28, Ni 0.02–0.29, Cr 0.09–0.28, Cd 0.06–2.76; liver: Fe 14.41–179.54, Mn 0.51–6.12, Zn 11.96–197.54, Pb 0.13–10.21, Cu 1.03–18.04, Co 0.00–0.69, Ni 0.00–10.60, Cr 0.05–0.66, Cd 0.10–3.29; kidney: Fe 48.90–131.28, Mn 0.70–3.04, Zn 18.84–317.39, Pb 0.11–14.57, Cu 0.99–5.98, Co 0.15–4.00, Ni 0.03–1.12, Cr 0.11–0.97, Cd 0.25–10.60. Monitored metals in the majority of cases were accumulated more in kidney and liver, and less in muscle. Significant interspecific differences among metals accumulation in tissues (except for lead accumulation in muscle and liver, nickel in all tissues, chromium in muscle, and cadmium in internal organs) were detected. From the viewpoint of safe fish consumption, the concentrations of lead and cadmium as high risk metals exceeded the maximum permissible limit in analyzed samples. On this account, fish from the lower Nitra River are not safe for human consumption