Accumulation characteristics of heavy metals and dietary risk assessment of Bellamya aeruginosa in the Xiangjiang River, Lake Dongting Basin

Abstract

To provide food safety information of Bellamya aeruginosa in Hunan, six populations from urban sections along Xiangjiang River, Lake Dongting Basin were collected for analyzing their bioaccumulation characteristics of six heavy metals (As, Cd, Pb, Cu, Zn and Cr)in foot and visceral masses. The pollution and dietary risk of heavy metals were also assessed using different approaches, including the single factor pollution index method, the weekly/monthly average intakes method and the target hazard quotient (THQ)method, respectively. The results showed that the average bioaccumulation values of As, Cd, Pb, Cu and Zn in the foot were 0.92, 1.65, 0.90, 13.01 and 67.62 mg/kg, respectively, while Cr was not detected. The excesses of As, Cd, Pb and Cu in the foot were 87.06%, 27.06%, 24.72% and 2.35%, respectively. The average bioaccumulation values of As, Cd, Pb, Cu, Zn and Cr in the visceral masses were 9.61, 3.21, 3.75, 33.58, 169.05 and 1.23 mg/kg, respectively. The excesses of As, Cd, Pb, Cu and Cr in the visceral masses were 100%, 71.76%, 65.88%, 14.12% and 75.8%, respectively. The mean and maximum weekly intakes of As, Pb, Cu, and Zn for adult in all analyzed sections were lower than the tentative weekly tolerable intake reference value (PTWI)proposed by the Joint FAO/WHO Joint Committee of Experts on Food Additives (JECFA). However, the average monthly Cd intake of adults along the Zhuzhou sections exceeds the monthly tolerance intake reference value, and the maximum value is 3.44 times of the reference value. The maximum monthly Cd intake of adults in the Yongzhou and Xiangtan sections are 1.16 and 1.68 times of their corresponding reference values, respectively. Except As, the THQ value of Bellamya aeruginosa was far less than 1, but all TTHQ values were equal or greater than 1. Overall, the results indicated that the B. aeruginosa in the six urban sections along Xiangjiang River were under a certain pollution, especially in Hengyang, Xiangtan and Zhuzhou. Furthermore, the amount of heavy metal bioaccumulation in the visceral masses of the B. aeruginosa in each river section was higher than that of the foot. Therefore, there are potential health risks of B. aeruginosa via long-term consumption by residents along the Xiangjiang River.