Heavy metal contamination and risk assessments in the surface water of Tanguar Haor, Bangladesh

• Cu and Cr are mostly responsible for water contamination. • The concentrations of Cr and Pb in water exceed international standard limits. • The carcinogenic risk assessment indicates a significant cancer risk for humans. • The Pearson correlation shows that pollution originates from anthropogenic sources. Heavy metal pollution, distribution, and health concerns in Tanguar Haor's surface water were evaluated in this study. Overall, the concentration of heavy metals was as follows: Ni > Cr > Pb > Zn > Cu > Mn. Cu significantly contaminated most water samples, according to the enrichment factor ( EF ), contamination factor ( CF ), pollution load index ( PLI ), and potential ecological risk ( PER ). As Cr influenced the heavy metal evaluation index ( HEI ) and heavy metal pollution index ( HPI ), Tanguar Haor water is severely contaminated. The hazard index ( HI ) and particular hazard quotients ( HQ s) for adults and children demonstrated no non-carcinogenic heavy metal risk from cutaneous exposure. In addition, every station discovered that the values of Cr and Pb were much beyond the permitted limit given by the Bureau of Indian Standards (BIS), the Environment Conservation Rules (ECR), and the World Health Organization (WHO). Both adults and children have significant Cr's carcinogenic risk. However, adults are more vulnerable to both carcinogenic and non-carcinogenic risks. Thus, S12, near Barek Tila station, is severely toxic and dangerous. Pearson correlation showed a substantial positive correlation between Cu-Mn, Ni-Cu, Cu-Pb, and Cr-Ni, suggesting the same origins, whereas Zn and Mn were uncorrelated, showing separate origins. Primary metal contamination in Tanguar Haor, Bangladesh, comes from agricultural, household, and industrial wastes directly dumped into the waterways. Excessive metal contamination may affect local water quality, fish, food, livelihoods, and public health. Regional water quality must be monitored for metal levels to protect human and environmental health.