Elements in Invasive Redclaw Crayfish Cherax quadricarinatus Pose Human Health Risks in the Largest Floodplain System of South Africa

The Australian redclaw crayfish, Cherax quadricarinatus, has been introduced globally for aquacultural purposes, and invasive wild populations have established in several countries. An increase in population growth, has caused several low-income and rural communities to utilise it as an inexpensive protein source. Despite this introduction, limited research has been done on element accumulation, and the risks for human consumption. This study focused on elemental accumulation in C. quadricarinatus from two rivers in the Phongolo River Floodplain (PRF), South Africa. The non-carcinogenic and carcinogenic human health risks associated with its consumption were calculated. The accumulation order in the PRF was Zn > Cu > Pb > Cr > As > Ni > Hg > Cd. Elevated concentrations of As and Hg, as well as As, Cr, and Ni posed non-carcinogenic and carcinogenic risks, respectively. These results highlight that wild populations of C. quadricarinatus not only pose a threat to aquatic ecosystems but also potentially cause human health risks when consumed.