Seasonal Variations and Health Risk of Heavy Metals in the Muscle of Crucian Carp (Carassius auratus) Cultured in Subsidence Ponds near Suzhou, East-Central China

Abstract

Concentrations of Cd, Cr, Zn, Pb, Cu, Mn, and Ni in the muscle of Carassius auratus collected from the subsidence ponds near Suzhou were detected in four different seasons. Mean levels of Cd, Cr, Zn, Pb, and Cu in fish muscle, except Mn and Ni, were below the benchmarks for safe limits as recommended by various authorities worldwide. In general, the metals’ concentrations found during winter were comparatively higher than those of the other seasons. Correlation study exhibited diverse relationships among the metals in different seasons, and a few significant relationships were found between metal level and fish size. Potential noncarcinogenic and carcinogenic health risks related to the metals in C. auratus were assessed using cancer risk-assessment guidelines approved by the US Environmental protection Agency. Although Mn and Ni concentrations exceeded the limits in some ponds, the calculated daily and weekly intakes of Cd, Cr, Zn, Pb, Cu, Mn, and Ni through fish consumption were significantly lower than the permissible limits. In relation to the noncarcinogenic and carcinogenic risks to human, health risks posed by metals in winter were much higher, and all the risks posed by heavy metals alone and in combination were lower than the safe limits. Consequently, consumption of C. auratus from the subsidence ponds on regular basis was considered safe.