A comprehensive analysis of health risks from metal contamination in the Sundarbans mangrove forest ecosystem in Bangladesh.

Objectives: The metal contamination levels in soil, water, and fish samples from the Sundarbans in Bangladesh were thoroughly examined. Key pollutants were identified using Principal Component Analysis (PCA), and pollution and health risks were evaluated using indices like TRI, Igeo, and Pearson correlation coefficients. Metal concentrations (Mn, Cu, Zn, Pb, Cd, Cr, As, Ni, Hg) were analyzed in various regions of the Sundarbans. In addition, the study extensively evaluated pollution severity and toxicity using indices like PLI, MPI, and TRI to assess the health risks associated with consuming fish. Methods: The study utilized different techniques to evaluate metal pollution in the Sundarbans. Fifteen locations were sampled for soil, water, and fish and then analyzed for metal concentrations using AAS. To evaluate the health risks related to fish consumption, the study measured the Estimated Daily Intake (EDI) and examined bioconcentration patterns in various fish species. Risk assessments utilized indices like Pollution Load Index (PLI), Metal Pollution Index (MPI), Toxicity Risk Index (TRI), Enrichment Factor (EF), Geoaccumulation Index (Igeo), and Contamination Factor (CF). Statistical methods such as Pearson correlation coefficients and PCA were used to assess the connection between metal concentrations and pollution risks. Specific contamination levels were emphasized using contamination factors and modified contamination factors. Results: Significant levels of metal contamination were uncovered in the Sundarbans during the study. Pb, Cd, Mn, Ni, Hg, and Cr were detected at high concentrations in soil, water, and fish samples from fifteen sites. Soil showed moderate pollution (Igeo: 1–2) for Mn, Pb (highest 1.7783), and Zn (lowest-1.2153). Water had Pb with the highest Igeo of 1.9951. Fish showed the highest Igeo values for Pb at 1.9259 and Cd at 1.9510. The Gangetic mystus had a high EDI of Zinc (Zn) at 2.3 µg/kg body weight per day, posing health risks if consumed. The concentration of mercury in Goby fish was 0.45 mg/kg, whereas Pama croaker had only 0.12 mg/kg of zinc. High Total Target Cancer Risk values of (1.7 × 10³), PLI 3.2–5.6, MPI 2.7–4.8, and TRI 4.1–6.3 underscored severe pollution. The EF values ranged from 4.5 to 7.2, and Pb (3.2) and Cd (2.8) showed significant geoaccumulation as per the Igeo. The CF indicated significant contamination, ranging from 2.5 to 6.1. The results of Pearson correlation coefficients and PCA confirm that pollution risks have a significant impact on both aquatic life and human health. Conclusion: The study uncovered severe metal contamination in soil, water, and fish samples from the Sundarbans. High TRI values indicated substantial toxicity risks, threatening ecosystems, human health, and water quality. Principal Component Analysis identified critical pollutants, revealing that Pb, Cd, Mn, Ni, Hg, and Cr levels were dangerously high. Immediate action is needed to mitigate these risks, especially for children consuming contaminated fish, highlighting urgent health and environmental concerns. [ABSTRACT FROM AUTHOR]