A comparison of accumulation and depuration effect of dissolved hexavalent chromium (Cr6+) in head and muscle of bighead carp (Aristichthys nobilis) and assessment of the potential health risk for consumers

In this study, bighead carp (Aristichthys nobilis) were exposed to waterborne Cr6+ of 0.01, 0.1, 1 and 5 mg/L for 14 days and subsequently transferred to clean water for another 14 days. The Cr6+ contents in some edible parts, such as dorsal muscle, ventral muscle and head were detected. The Cr6+ concentrations in the three parts were in the order of: head > ventral muscle > dorsal muscle with significant increase during exposure period and remarkable decrease when kept at clean water during depuration stage. The head contained higher fat than that of muscle and the Cr6+ levels of these parts showed significantly positive correlation with fat content, however, the Cr6+ contents in the separated fat were extremely low. The Cr6+ levels determined in tissues can tell a real story rather than the correlation coefficient. Fish head poses a higher potential health risk than muscle due to heavy metals pollution.