Multivariate Analysis and Characteristics of Selected Potentially Toxic Elements in Muscle Tissue and Hepatopancreas of Oysters (Crassostrea spp.) from Coastal Areas of Quang Ninh: Bioaccumulation Features, Health Risk Assessments and Origin Sources.

The presence of potentially toxic elements (PTEs) in the marine environment poses potential risks to both marine ecosystems and human health. This study investigated concentrations, bioaccumulation patterns, and associated health risks of PTEs in oysters (Crassostrea spp.) collected from the coastal waters of Quang Ninh, Vietnam. Zinc (Zn) had the highest concentrations (65.4 mg/kg in muscle tissue and 56.8 mg/kg in hepatopancreas), wherea mercury (Hg) showed the lowest concentrations (0.0064 mg/kg and 0.0034 mg/kg, respectively) in both organs. There was a positive correlation between shell size and weight with PTE concentrations in both organs, suggesting increased bioaccumulation with long-term exposure to the environment. Principal component analysis (PCA) identified three distinct sources of PTEs: anthropogenic inputs from industrial, agricultural, and transportation activities (PC1, variance 33.0%), mixed anthropogenic and natural sources (PC2, variance 22.9%), and natural sources combined with the impact of coal mining in the region (PC3, variance 16.8%). Health risk assessment using the Risk Quotient (RQ) revealed that cadmium (Cd) in the hepatopancreas posed the most significant health concern, with RQ values exceeding 1 under the worst-case scenarios. These findings provided a valuable scientific basis for regional environmental pollution monitoring and control measures. In addition, the results emphasize the need for continuous monitoring of Cd concentrations for sustainable aquaculture development in the region.