Groundwater and soil contaminated with arsenic (As) are significant environmental health concerns worldwide and have become a serious health issue for millions of Bangladeshis. This contaminated groundwater is commonly used for Boro rice production during the dry season in Bangladesh, leading to long-term As deposition in soils. The consequences of long-term irrigation with As-contaminated groundwater for bioaccumulation in food crops and hence dietary exposure to As and other metals are a threat to the resident. Highly arsenic (292 µg L⁻¹) contaminated groundwater used to irrigate in the study area increases the As content (mean: 24.5 mg kg⁻¹) in irrigated soil than non-irrigated soil (mean: 8.43 mg kg⁻¹). The high enrichment factor (mean: 16.8) and geo-accumulation index (mean: 2.33) revealed that the soil of that particular area is strongly contaminated by As. In paddy, roots showed the maximum As concentration (mean: 139.8 mg kg⁻¹) followed by straws (mean: 5.25 mg kg⁻¹) and grains (mean: 1.23 mg kg⁻¹) where 85–95% As exist in the roots of paddy, and only 0.8–1% As translocate to the harvesting part of the rice in the study area. In food samples, two rice grains (R-1, R-3) and a drumstick (FS-5) exceed the Indian standard of As concentration (As: 1.1 mg kg⁻¹) in food. According to World Health Organization, the metals concentrations in all food samples exceeded the permissible limit except for Cu and Pb in red amaranth; Cr, Cd, and Pb in guava; and Cu and Cd in drumsticks. Higher values of bioaccumulation factor (BAF: 2.94) and the net translocation coefficient (NTC: 6.17) indicate As-accumulation in food from adjacent contaminated soil. Daily metal intake from food consumption suggests that the heavy metal(loid)s like As, Ni, and Pb represent high concentrations and exceed the daily ingestion limits (As: 3 µg kg⁻¹ day⁻¹, Ni: 1.3 µg kg⁻¹ day⁻¹, and Pb: 3.57 µg kg⁻¹ day⁻¹) developed by the Food and Agriculture Organization and European Food Safety Authority. Carcinogenic (> 10^–6) and non-carcinogenic (HQ > 1) health risks of As, Pb, Cd, and Cu suggest that the community was at potential health risk according to the United States Environmental Protection Agency.

The study area is located in the southwestern part of Bangladesh. Twenty-six groundwater samples were collected from both shallow and deep tube wells ranging in depth from 20 to 60 m. Multivariate statistical analyses including factor analysis, cluster analysis and multidimensional scaling were applied to the hydrogeochemical data. The results show that a few factors adequately represent the traits that define water chemistry. The first factor of Fe and HCO₃ is strongly influenced by bacterial Fe (III) reduction which would raise both Fe and HCO₃ concentrations in water. Na, Cl, Ca, Mg and PO₄ are grouped under the second factor representing the salinity sources of waters. The third factor, represented by As, Mn, SO₄ and K is related to As mobilization processes. Cluster analysis has been applied for the interpretation of the groundwater quality data. Initially Piper methods have been employed to obtain a first idea on the water types in the study area. Hierarchical cluster analysis was carried out for further classification of water types in the study area. Twelve components, namely, pH, Fe, Mn, As, Ca, Mg, Na, K, HCO₃, Cl, SO₄ and NO₃ have been used for this purpose. With hierarchical clustering analysis the water samples have been classified into 3 clusters. They are very high, high and moderately As-enriched groundwater as well as groundwater with elevated SO₄.