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River water and sediment embody environmental characteristics that give valuable eco-environmental information. Due to rapid industrialization, the aquatic environment of any urban river can be seriously polluted by heavy metals (HMs). The global concern is caused by heavy metal pollution because of its potential harm to aquatic ecosystems and human health. In the Bhairab River, Bangladesh, surface sediment concentrations of globally alarming toxic metals such as arsenic (As), chromium (Cr), cadmium (Cd), and lead (Pb) were measured to determine the ecological and human health risks of the riverine ecosystem. The average As, Cr, Cd, and Pb concentrations in water were 3.55, 31.74, 1.44, and 23.82 μg/L, respectively, and in sediment were 4.13, 34.17, 1.66, and 25.46 mg/kg, respectively. During the winter, metals in sediment were higher than during the summer. For most sediment samples, the enrichment factor (EF), contamination factor (CF), geoaccumulation index (I geo), pollution load index (PLI) of As, Cr, Cd, and Pb indicated moderate contamination. The potential ecological risk (PER) in sediment followed the descending order of Cd > As > Pb > Cr. The contamination level of toxic metals implied that the condition is frightening and probably severely affecting the aquatic ecology of this riverine ecosystem. [ABSTRACT FROM AUTHOR]

Rooftop cultivation of vegetables is considered as a potential food source for urban population. However, rooftop products in the urban area can be contaminated by different types of pollutants like toxic metals and polycyclic aromatic hydrocarbons (PAHs). The present study is the first that investigated the concentrations of toxic metals and PAHs in rooftop soils and vegetables grown in the urban and peri-urban areas of Bangladesh. Red amaranth and Spinach were selected for rooftop cultivation, and both soil and vegetable samples were collected and analyzed for determining the concentrations of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) as toxic metals, while naphthalene, fluorene, phenanthrene, anthracene, pyrene, benzo(a)anthracene, and chrysene as PAHs. The study observed that urban rooftop soil and vegetables were highly contaminated with toxic metals and PAHs as compared to peri-urban rooftop samples. The metal concentrations were found in order of Zn > Cu > Pb > Cd, however, Pb and Cd concentrations in urban vegetables exceeded the safe limit. On contrary, negligible concentrations of PAHs were detected in both urban and peri-urban rooftop vegetables. The values of health risk indices revealed that the concentrations of toxic metals and PAHs in urban rooftop vegetables would not pose any carcinogenic and non-carcinogenic health risks for adults and children and thus are considered to be safe for consumption. The findings of this study will provide scientific evidence to the policy makers and public administrations for urban agriculture based policy formulation as well as will encourage the city dwellers towards urban rooftop agricultural practices. [ABSTRACT FROM AUTHOR]

Toxic metal contamination in foodstuff is a major concern for public health and human beings are continuously exposed to toxic metals through consumption of cereals, pulses, vegetables, fruits, and other crops grown in the metals contaminated soil. The present study was conducted to investigate the concentrations of chromium (Cr), nickel (Ni), copper (Cu), arsenic (As), cadmium (Cd), and lead (Pb) in foodstuffs and their possible human health risks in Jhenaidah and Kushtia districts, Bangladesh. The range of Cr, Ni, Cu, As, Cd, and Pb in the studied foodstuffs were 1.57–12.52, 1.71–37.78, 1.97–16.67, 0.36–3.72, 0.00–4.02, and 1.04–10.88 mg/kg dw, respectively. Multivariate principal component analysis revealed significant anthropogenic contributions of Cr, Cu, As, and Pb in the studied foodstuffs. 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) of the studied metals, excluding Cr, from all foodstuffs were higher than 1, indicating that if people consume these types of foods in their diet, they might pose risk to these metals. The estimated target carcinogenic risk of As was higher than USEPA standard (10−4), indicating increased risk of cancer for adults and children in the study area. [ABSTRACT FROM AUTHOR]

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 (Cfi), geoaccumulation index (Igeo), 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, Igeo, Cfi, 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. [ABSTRACT FROM AUTHOR]

Metal accumulation (As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) in Korotoa River sediment was studied in order to determine the metal content, distribution, sources, and their possible ecological impacts on the riverine ecosystem. Our study found significant spatial patterns of toxic metal concentration and principal coordinate analysis (PCoA) accounted for 45.2% of spatial variation from upstream to downstream. Metal contents were compared to sediment quality standards and found all studied metal concentrations exceeded the Threshold Effect Level (TEL) whereas Cr and Ni surpassed probable effect levels. All metal concentrations were higher than Average Shale Value (ASV) except Mn and Hg. The positive matrix factorization (PMF) and absolute principal component score-multiple linear regression models (APCS-MLR) were applied to identify promising sources of metals in sediment samples. Both models identified three potential sources i.e. natural source, traffic emission, and industrial pollution, which accounted for 50.32%, 20.16%, and 29.51% in PMF model whereas 43.56%, 29.42%, and 27.02% in APCS-MLR model, respectively. Based on ecological risk assessment, pollution load index (7.74), potential ecological risk (1078.45), Nemerow pollution index (5.50), and multiple probable effect concentrations quality (7.73) showed very high contamination of toxic metal in sediment samples. [Display omitted] • Toxic metals contamination with sources in the sediment of Korotoa River were studied. • Principal coordinate analysis accounted for 45.2% of spatial variation. • Both PMF and APCS-MLR model identified natural source, traffic emission, and industrial pollution. • PLI, PER, P N , and mPECQ showed very high contamination of metals in sediment. [ABSTRACT FROM AUTHOR]