Heavy metal enrichment analysis and edible evaluation of giant salamander cultured in Wulong

【Objective】To study the breeding environment quality of Wulong giant salamander and its potential risk to human health by consuming，which could provide reference for the cleaner production and quality improvement of giant salamander.【Method】The heavy metal contents of copper（Cu），lead（Pb），zinc（Zn），chromium（Cr），nickel（Ni）and manganese（Mn）in the water of the breeding base of Wulong giant salamander and the muscle and liver tissues of 1-year-old and 3-year-old giant Salamander were determined by flame atomic absorption spectrophotometry，the migration and enrichment characteristics of heavy metals were analyzed. The pollution degree of heavy metals was evaluated by single factor pollution index method and Nemerow comprehensive pollution index method. Bioconcentration factor （BCF），bioaccumulation factor（BAF），target hazard quotient（THQ），and total target hazard quotient（TTHQ）were used to evaluate the potential human health risks of eating tissues and organs of giant salamander.【Result】The average contents of Cu，Pb，Zn，Cr，Ni and Mn in the cultured water as well as muscle and liver of giant salamanders were 0.0030，0.0280，0.0008，0.0030，0.0105 and 0.0061 mg/L respectively，and 1.0002，0.3616，8.3566，0.0230，0.0075 and 0.1982 mg/kg respectively. These levels did not exceed food quality standards in China，indicating no obvious heavy metal contamination in the aquaculture water. However，the Pb content in the muscle and liver tissues of the giant salamander exceeded the limit set by the Food and Agriculture Organization of the United Nations，the World Health Organization（FAO/WHO），and the European Commission（0.3 mg/kg），posing a potential risk of Pb pollution. The accumulation capacity of Zn and Cu in the muscle and liver was strong，and BCF of Zn increased with the age of the giant salamander， with higher accumulation observed in the liver compared to muscle tissue，making liver consuming more risky. Both THQ and TTHQ were below 1，suggesting no obvious health risks associated with consuming giant salamander tissues. However，Pb contributed greatly to TTHQ.【Conclusion】Consumption of giant salamander from the Wulong breeding base poses no obvious risk of heavy metal exposure to human and is considered safe. Nevertheless，it is essential to strengthen the control of Pb sources in aquaculture water and monitor Pb levels in giant salamanders to enhance the food safety of giant salamander products from Wulong，Chongqing.