Trace elements in Mytella strigata and Perna viridis from three Chinese coastal regions: comparison and safety assessments.

Food safety concerns affect life health. Mussels are a significant source of high-quality marine protein in China, but their ability to bioaccumulate heavy metals raises concerns regarding food safety, warranting further investigation. This study compares the concentrations of seven trace elements include six heavy metals (Cd, Cr, Hg, Pb, Cu, Zn) and harmful element inorganic arsenic (iAs) in the soft tissues of two mussel species, i.e. the invasive Mytella strigata (Hanley, 1843) and the native, commercially important Perna viridis (Linnaeus, 1758), collected from same habitats of Haikou, Shanwei, and Zhanjiang, China. The results revealed species-related variations in trace elements concentrations. Zinc (Zn) exhibited the highest concentration, while cadmium (Cd) and mercury (Hg) had the lowest levels in both mussel species. M. strigata was more proficient in accumulating iAs, Cu, and Pb than P. viridis, but was less efficient in accumulating Cd. Correlation analysis showed significant positive correlations between iAs-Pb and iAs-Zn (p < 0.05). Heavy metal pollution and food safety evaluations indicated that iAs had the highest single-factor pollution index in both species across all locations. The Nemerow comprehensive indices for M. strigata from both Shanwei and Zhanjiang, and P. viridis from Zhanjiang, exceeded 3, indicating severe pollution. Target hazard quotient analysis of iAs suggested a potential health risk for M. strigata from Shanwei. Therefore, the trace elements and food safety of wild mussels, especially invasive mussels, should draw more attention.