The Accumulation of Toxic Elements (Pb, Hg, Cd, As, and Cu) in Red Swamp Crayfish (Procambarus clarkii) in Qianjiang and the Associated Risks to Human Health

SIMPLE SUMMARY: Consumers have expressed concern regarding the food safety of aquatic products in light of escalating global environmental pollution. The potential accumulation of heavy metals in red swamp crayfish, an omnivorous aquatic species, may present a significant risk to human health. Hence, a comprehensive multi-point sampling was carried out in Qianjiang, the foremost export city in China, followed by a meticulous risk evaluation of the red swamp crayfish originating from Qianjiang. In the study, we found eight significant interaction relationships that may be utilized to construct predictive models for the spatial distribution of heavy metals in crayfish tissue. The findings indicate that the abdomen muscle of crayfish does not present any discernible risk to human well-being. However, a minute fraction of crayfish hepatopancreas samples exhibited excessive levels of arsenic, rendering it inadvisable for excessive consumption. ABSTRACT: Due to rapidly expanding crayfish consumption worldwide, the food safety of red swamp crayfish (Procambarus clarkii) is of great concern. China is the largest consumer and producer of crayfish globally. As of yet, it is unknown whether the main crayfish production cities in China are within safe levels of toxic heavy metals and metalloids. For 16 consecutive years, Qianjiang city ranked first in China in processing export volumes of red swamp crayfish. This study presents a comprehensive analysis of the enrichment levels and associated health risks of the species in Qianjiang. In our research, samples of four crayfish tissues, including the head, hepatopancreas, gills, and muscles, were collected from 38 sampling sites distributed in Qianjiang to evaluate the concentration levels of five heavy metals (Pb, Hg, Cd, As, and Cu). The concentration levels of all five metals in muscle did not surpass the national standard. Furthermore, eight significant correlations have been found. For further in-depth assess risk of crayfish in Qianjiang, estimated daily intake (EDI), target hazard quotient (THQ), carcinogenic risk (CR), and estimated maximum allowable consumption rates (CR(mm)) were evaluated in the abdomen muscle and hepatopancreas. The THQ values for each metal were found to be less than 1, while the CR values were below 10(–6). Additionally, the CR(mm) for adults was determined to be 17.2 meals per month. These findings, based on the analysis of five metallic elements included in this study, suggest that the consumption of crayfish abdomen muscle in Qianjiang does not pose any significant health risks. However, it is noteworthy that certain regions exhibit elevated levels of arsenic in the hepatopancreas, surpassing the national standard, thereby rendering them unsuitable for excessive consumption. In general, the findings can be used to provide guidance for safe dietary practices in China.