Water quality is a big concern for the humankind as it is the most important natural resource. Water is polluted by increasing activities of population and the necessity to provide them with goods and services that use water as a vital resource. In this study, surface water samples were collected in the summer and the winter season from Rupsa river, Bangladesh, and pH, electrical conductivity (EC), Cr, Ni, Cu, As, Cd and Pb concentrations were analyzed to assess the metal toxicity, identify the possible sources and determine health risk from metals in water. During the the summer season, the mean concentrations of Cr, Pb, As, Cu, Ni and Cd were measured as 7.20 ± 0.613, 7.09 ± 0.904, 5.45 ± 0.441, 5.36 ± 0.471, 3.85 ± 0.694 and 0.975 ± 0.106 µg/L, respectively, whereas the concentrations were measured as 8.87 ± 0.756, 7.32 ± 0.93, 6.05 ± 0.490, 6.02 ± 0.529, 5.48 ± 0.986 and 1.38 ± 0.151 µg/L, respectively, during the the winter season. Source identification like correlation analysis, Principal component analysis (PCA) and cluster analysis (CA) were applied to identify the source of toxic metals in water. Total heavy metal toxicity load and heavy metal evaluation index values were found to be higher than permissible value except for Cu. According to the ecological risk index classification, 85% of the total samples were found to pose moderate ecological risks, while the rest 15% were found to pose low ecological risks during both seasons. As showed high non-carcinogenic risk on the basis of single element via oral exposure. The hazard index value for oral exposure by male, female and children was found to be 4.17E + 00, 3.67E + 00 and 8.64E + 00, respectively; indicating that non-carcinogenic effects are obvious to occur. The carcinogenic risks of Ni and As due to regular exposure via oral and dermal contact pathways were higher than the standard value (>1.0E-04) which anticipated possible cancer risks to male, female and children in the study area.

Heavy metals are toxic in nature, and their contamination in foodstuff is a matter of concern for human health. The present study was conducted to assess the concentrations of chromium, nickel, copper, arsenic, cadmium, and lead in rice and vegetables and their possible human health risks in Tangail district, Bangladesh. Metals were measured by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion system. The average values of Cr, Ni, Cu, As, Cd, and Pb in rice and vegetables were 16.26, 16.11, 13.99, 2.28, 1.86, and 7.93 mg/kg, respectively. The average metal concentration in rice and vegetable species was in the decreasing order of okra > chili > bitter gourd > papaya > brinjal > bean > bottle gourd > rice > cucumber > sponge gourd > Indian spinach. The estimated daily intake (EDI) values of all the metals except Cu were higher than the maximum tolerable daily intake (MTDI). The target hazard quotients (THQs) values of Ni, Cu, As, Cd, and Pb exceeded the threshold value of 1 through consumption of rice and vegetables, indicating significant health risks to both adult and children. The target carcinogenic risk (TR) of As and Pb through consumption of rice and vegetables was higher than the USEPA threshold level (10⁻⁴). From the health point of view, this study clearly revealed that consumption of these contaminated rice and vegetables definitely poses carcinogenic and non-carcinogenic risks.

The present study was conducted to assess the pollution level and distribution of heavy metals and their ecological and health risk in sediments of the Rupsa River, Bangladesh. Heavy metals were measured by using inductively coupled plasma mass spectrometer. The mean concentration of Cr, Ni, Cu, As, Cd, and Pb in sediments was 25.26, 42.40, 68.81, 9.31, 3.78, and 32.57 mg/kg, respectively. Metals in sediment during winter were higher than summer season. Multivariate principal component analysis revealed significant anthropogenic contributions of Cr, Ni, As and Cd in sediment. The enrichment factor (EF), geoaccumulation index (I_geo), pollution load index (PLI), and contamination factor (Cⁱ_f) demonstrated that most of the sediment samples were heavily contaminated by Cd. The sum of toxic units in most of the sampling sites during winter season was greater than 4, indicating a moderate to serious toxicity of heavy metals in sediment. In view of the potential ecological risk, sediments of Rupsa River showed low to very high potential ecological risk. The chronic daily intake of metals were higher than oral RfD which was the result of metal contamination. The total hazard index for adult and children, about 100% sampling location possess (HI > 1) indicating pose non-cancer risk. The carcinogenic risks from As and Pb at all sites via ingestion and dermal contact were higher than acceptable ranges (10⁻⁴). This study suggested that more attention should be directed to the comprehensive risk assessment of heavy metals of this riverine aquatic environment.

Levels of heavy metals, i.e., chromium (Cr), nickel (Ni), copper (Cu), arsenic (As), cadmium (Cd), and lead (Pb) in surface sediment of Buriganga River, Bangladesh were investigated to assess ecological risk. The mean concentration of Cr, Ni, Cu, As, Cd, and Pb in sediments was 297, 240, 280, 21, 7.7, and 731 mg/kg, respectively. Certain indices, including the enrichment factor (EF), pollution load index (PLI), and contamination factor were used to assess the ecological risk. The mean range of PLI was 2.9 to 13 during winter and 2.4 to 11 during summer season, indicating progressive deterioration of sediment due to metal contamination. The sum of toxic units (∑TUs) for all the sampling sites was greater than 4, indicating a moderate to serious toxicity of heavy metals in sediment. However, the values of Cd ranging from 6.7 to 61 revealed that the examined sediments were strongly impacted by Cd. Considering the severity of potential ecological risk for single metal , the descending order of contaminants was Cd > Pb > Cu > Ni > As > Cr. In view of the potential ecological risk, sediments of Buriganga River showed considerable to very high potential ecological risk.

This study was conducted to assess the potential ecological and human health risk of toxic metals in agricultural soils near the industrial areas of Bangladesh. In this study, six toxic metals (chromium, nickel, copper, arsenic, cadmium, and lead) were assessed in 58 soil samples of five different sampling sites around the industrial areas of Jhenaidah and Kushtia districts in Bangladesh. Toxic metals were measured using inductively coupled plasma mass spectrometer. Potential ecological and human health risk were assessed through enrichment factor (EF), contamination factor (C_fⁱ), geoaccumulation index (I_geo), pollution load index (PLI), toxic unit analysis, chronic daily intake through exposure pathway, hazard quotient, and hazard index. The mean concentrations of Cr, Ni, Cu, As, Cd, and Pb were found to be 5.78, 21.0, 31.8, 8.05, 1.20, and 19.2 mg/kg, respectively. Metals concentrations were found below the recommended value set by Dutch standard, Canadian guidelines, and Australian guidelines except Cd. Principal component analysis indicates that most of the metals in agricultural soils are coming from industrial sector. The mean values of EF, I_geo, C_fⁱ, PLI, and toxic units were found safe level for all metals except Cd. In the view of potential ecological risk (PER), soils from all sampling sites indicated moderate to very high PER. Total target hazard quotients for all the studied metals in total sampling sites were <1 and cancer risk values were <10⁻⁶ indicating low noncarcinogenic and cancer risk for adult and children.