A kinetic study on accumulation and depuration of hexavalent chromium in crucian carp (Carassius auratus) reveals the potential health risk of fish head consumption

In this study, crucian carp (Carassius auratus) was exposed to graded levels of waterborne Cr6+ (0, 0.1, 1 and 10 mg/L) for 28 days and subsequently transferred to clean water for 20 days. Fish tissues were collected every 4 days. The Cr6+ levels in tissues were determined and the potential health risks from consuming fish muscle and fish head were assessed. The results indicated that the Cr6+ contents in the head were always higher than those in muscle and that 10 mg/L Cr6+ treatment conferred risk in fish head consumption throughout the entire experimental period. A further kinetic study on the accumulation and depuration of Cr6+ in tissues indicated that compared to muscle, the higher Cr6+ content in fish head was attributed to the greater uptake rate (k1) and kinetic bioconcentration factor (BCFk), although the k1 and BCFk values in the muscle and head were lower than those in the liver, kidney, intestines and gills. The maximum Cr6+ concentrations in tissues at theoretical equilibrium (Cmax) ranged from 0.55 mg/kg in muscle to 112 mg/kg in intestines with exposure to 10 mg/L Cr6+. Moreover, the results of the distributions and transitions of Cr6+ in fish tissues demonstrated that fish head and muscle were short-term storage organs while the kidney was a long-term storage organ for Cr6+. Overall, compare to muscle, fish head has a higher capacity for Cr6+ accumulation, which poses a higher potential health risk to humans, especially to children, once the fish is contaminated by Cr6+.

Automated summary

The study showed that crucian carp exposed to different levels of Cr6+ had higher concentrations in the head compared to muscle, with the head having a greater capacity for accumulation and bioconcentration of Cr6+. Fish exposed to 10 mg/L Cr6+ had higher potential health risks in terms of Cr6+ content in the head, especially for children.