Risk assessment on crayfish eating-related cadmium exposure among consumers in Jiangsu province

  Objective   To investigate crayfish eating-related cadmium exposure risk among consumers in Jiangsu province for providing evidences to food safety risk assessment by relevant departments.

  Methods   Cadmium contents were detected for a total of 408 crayfish samples (20, 220, and 168 samples of juvenile, adult, and precooked crayfish) randomly collected from farmers′ markets, supermarkets, wholesale markets and catering units in four municipalities/prefectures of Jiangsu province from June 2011 to September 2014. An on-site questionnaire survey was conducted among 377 crayfish consumers selected with multistage random sampling in 25 restaurants providing crayfish dishes in five municipalities/prefectures of Jiangsu province during July – September, 2014 to establish an intake assessment model for estimating crayfish eating-related cadmium exposure among the consumers.

  Results   The average cadmium content of the crayfish was 0.23 ± 0.72 mg/kg, with significantly higher content of head specimens than that of tail specimens (0.45 ± 0.97 vs. 0.01 ± 0.02 mg/kg) and higher content of juvenile crayfish specimens than that of adult/precooked crayfish specimens (1.11 ± 1.91 vs. 0.19 ± 0.68/0.18 ± 0.38 mg/kg) (all P < 0.05). For the consumers, the monthly amount of crayfish consumed was 0.56 ± 1.01 kg/month; the average monthly crayfish eating-related cadmium intake was 1.76 ± 3.56 μg/kg, with the 90th percentile of 4.71 μg/kg and upper limit of 8.57 μg/kg; and the cadmium intake accounted for 7.04%, 18.84% and 34.29% of the monthly tolerated intake (PTMI) and the margin of safety (MOS) values corresponding to the intakes were 14.20, 5.31 and 2.92, respectively. The average monthly crayfish eating-related cadmium intake could differ significantly by different eating behaviors, with estimated intakes of 0.09 ± 1.73, 2.44 ± 3.56, and 6.64 ± 3.26 μg/kg for the consumers eating only tail, both tail and head, and only head of crayfish, respectively (F = 33.718, P < 0.001). There was no significant difference in the monthly crayfish eating-related intake of cadmium among consumers at various ages (P > 0.05). The monthly MOS value of cadmium intake due to crayfish consumption was > 1 for the consumers of different ages and eating different body parts of crayfish, indicating that the risk of cadmium exposure for crayfish consumers in Jiangsu province was acceptable.

  Conclusion  The risk of crayfish eating-related cadmium exposure for crayfish consumers in Jiangsu province is within an acceptable range, but the cadmium content of the head and juvenile crayfish is high, and long-term consumption of large amounts of crayfish may cause health hazards. The results suggest that it is better for consumers not to eat head of crayfish and juvenile crayfish to decrease cadmium exposure.