Search

Pollution of sediments by metals is a global issue, with developing countries like Nigeria, having its large PORTION. Niger River, the most valued river in Nigeria, is under serious anthropogenic perturbations with no measures to save the river by concerned authorities. Samplings were conducted at 12 designated stations of the lower reaches of the river within the southern region of Nigeria. The elements (As, Fe, Cu, Pb, Cd, Zn and Hg) were analysed using atomic absorption spectrophotometer. The average levels of As, Fe, Cu, Pb, Cd, Zn and Hg in the river sediments were 12, 115, 18, 11, 0.71, 36 and 0.59 mg/kg, respectively. Certain indices, including the enrichment factor (EF), geoaccumulation index (Igeo), pollution load index (PLI) and contamination factor (CF), were used to assess the ecological risk posed by metals in sediment. Cadmium in five locations (SP4− SP8) and Hg for sites SP4 and SP5, had their Igeo values above 1.0, which implies that these stations were moderately polluted. The EF values for Cd, Hg and As were above 1.5 (EF > 1.5) in sites SP4 and SP5 especially in the dry season, indicating strong enrichment of these elements in sediment to anthropogenic influences. Potential ecological risks of heavy metals in sediment showed weak to very high threat which implies that the condition is much frightening to the biota and inhabitants in the vicinity of the river as well. [ABSTRACT FROM AUTHOR]

In Dhaka megacity (Bangladesh), lakes located in the most exclusive areas are considered crucial urban water bodies. However, these water sources are confronting a heavy load of organic and inorganic pollutants by anthropogenic activities and are being polluted continuously. In this review , 50 relevant published documents on the lake water of Dhaka megacity to highlight the overall water quality status and the potential ecological and human health risks associated with contaminations were studied. The retrieved documents were organized according to the relevant information and examined thoroughly. After a careful review, it was found that most of the lake water in Dhaka city is severely contaminated with heavy metals such as Pb, Cd, Cu, Zn, and Mn with a higher concentration of Pb and Cd than the guideline values for drinking and industrial uses. The physicochemical properties and microbial contamination with an elevated level of fecal coliforms in lake water indicate very poor water quality in all lakes. The EC and TDS in most of the lake water exceeded the standard limits with the highest EC value (4920 µS/cm) for Gulshan Lake. The indices-based water quality assessment revealed considerable heavy metal contamination in the lake's water. Few lakes are found at a minimal level of ecological risks. The assessments of health risk indicate lower non-cancer risk. Overall, it can be inferred that the lake water in the Dhaka megacity does not meet the requirements for domestic, drinking, fishing, and industrial uses. This review study will be helpful for the policymakers and environmentalists to know about the status and sources of pollution in the lake water in the megacity which in turn assist to take necessary actions to mitigate the pollution level from the studied lakes of Dhaka city, Bangladesh. [ABSTRACT FROM AUTHOR]

An effective toxicological assessment of soil-metal bioavailability and plant translocation processes is needed in view of the growing negative impact of trace element pollution on the terrestrial environment and human health. This study was conducted to assess the toxicological processes that regulate the plants' trace element absorption into their tissues, the suitability for human use, the potential sources of trace elements, and the risk to human health, using an integrated research methodology. Soils and sweet potato plants were collected from agricultural fields near the tannery waste disposal sites of Dhaka City, Bangladesh and inductively coupled plasma mass spectrometers (ICP-MS) were used to analyze the essential and toxic elements. The mean concentrations of total elements in soil followed the descending order of Fe > Zn > Mn > Cr > Ni > Pb > Cu > As > Cd and in plant Fe > Zn > Cu > Cr > Ni > Mn > Pb > As > Cd. In the edible tissues of sweet potato, the concentrations of essential and toxic elements exceeded the maximum permissible levels, indicating not safe for human consumption. The translocation factor (TF) revealed that studied elements are more accumulated in the leaves than tubers. The enrichment factor revealed minimal to very high enrichment of essential and toxic elements in the plant parts while the contamination factor showed low to very high contamination. Considering the health risk of toxic elements from plant samples, As and Pb caused non-cancer and cancer risk on human health. However, the present results suggested that regular monitoring of these essential and toxic elements in soil and plants as well as other food materials around the abandoned tannery waste disposal sites are necessary to prevent excessive build-up of these elements in the food chain. [ABSTRACT FROM AUTHOR]

The southwestern coastal areas of Bangladesh have been severely suffering from the scarcity of safe drinking water due to the combined consequences of hydrogeological processes, groundwater depletion, saltwater intrusion, and adverse anthropogenic activities. This concern results in serious public health hazards, particularly for children at primary schools. This study was conducted to evaluate some physiochemical and bacteriological parameters of drinking water from tube wells (TWs) located at primary schools in Kalapara upazila, Patuakhali district, Bangladesh. Water samples were collected from 65 TWs. The levels of the examined parameters recorded the following ranges: pH 6.9–8.3, electrical conductivity 774.3–1987.0 μS/cm, Fe 0.12–15.78 mg/L, As 0.0–0.03 mg/L, and Cl− 9.0–354.0 mg/L. The results revealed that 11% of TWs exceeded the level of Fe recommended by the National Drinking Water Quality Standard in Bangladesh, while other physiochemical parameters fit with the national standards. The bacteriological analysis revealed that 60% of TWs delivered fecal coliform (FC)-free water, while 40% of TWs supplied total coliform (TC)-free water. However, about 26% of TWs had the potential to pose non-carcinogenic health problems for children from As, while only 5% of TWs were found to cause probable non-carcinogenic risks for adults. The calculated carcinogenic risks values for adult male and female were within the USEPA acceptable range (1 × 10−4–1 × 10−6), except for only one sampling point, while four sampling points (6.15% of TWs) exhibited carcinogenic risks for children. This result indicates that the ingestion of drinking water from those TWs may pose lifetime cancer risks to children. [ABSTRACT FROM AUTHOR]

Rice is the staple food of Bangladeshi people and is consumed at least twice a day. Thus, the presence of toxic metals in rice grains has become a major public health concern in Bangladesh. The present research was conducted to investigate the concentrations of toxic metals in rice grains and their possible human health risks in the Tangail district of Bangladesh. Toxic metals were measured by using an inductively coupled plasma mass spectrometer (ICP-MS), and the mean concentrations of toxic metals in rice samples were found in order of Cr > Pb > Ni > As > Cu > Cd. The concentrations of Cr, Pb, As, and Cd in the studied rice grain samples exceeded the FAO/WHO standard values for food samples by 100%, whereas the Ni concentrations by 10%. The principal component analysis (PCA) revealed significant anthropogenic contributions of Cr, Ni, As, and Pb concentrations in rice grains. The metal concentrations in rice grain samples showed strong significant correlations by forming primary clusters with each other. The estimated daily intake (EDI) values of Cr, Ni, As, Cd, and Pb from all samples were higher than the maximum tolerable daily intake (MTDI) allowed. The total targeted hazard quotient (TTHQ) values of Cu, Ni, As, Cd, and Pb also exceeded the threshold value of 1.00, indicating a potential non-carcinogenic risk. The estimated target carcinogenic risk of As was higher than the USEPA threshold level 10−4 (0.0001) indicating increased risk of cancer for adults and children in the study area. [ABSTRACT FROM AUTHOR]

Nitrogen (N) plays a key role for plant life cycle. It is available in agricultural soils as the form of nitrate and ammonium (NH4+) where nitrate (NO3−) is a major nutrient. Plants are able to sense NO3− in their environment, allowing them to quickly respond to the dramatic fluctuations of its availability. As a main feature of plant autotrophy, assimilation of inorganic N is not only of fundamental interest to the crop, but also a crucial factor in crop productivity. Furthermore, over the last couple of years, N sensing has been shown to be affected by different external factors, which act as local signals to trigger systemic signaling coordinated by mobile signals in plants body. During recent years, a breakthrough arising from the improved knowledge is a better understanding of NO3− integration and hormone signaling pathways of plants that explains the extraordinary developmental plasticity of NO3− response. This review highlights the novel aspect of N responsive sensors, transporters, and signaling molecules in plants with a brief introduction on the metabolic pathways and discusses their potential roles in N sensing. [ABSTRACT FROM AUTHOR]

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. [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]

The objective of this study was to determine the distribution of cadmium (Cd) accumulation in tobacco and identify the relationship between soil properties and plant Cd concentration. Forty soil and tobacco samples were collected from the Sichuan Basin, China (Panzhihua, Luzhou, Guangyuan and Yibin). The results showed the highest Cd in soil (2.94 mg kg−1) was in Yibin. Correspondingly, Cd concentrations in tobacco from Yibin were significantly higher than those from the other regions. The Cd concentrations in tobacco from Yibin, Luzhou, Guangyuan and Panzhihua were from 2.22 to 13.14, 0.59 to 2.12, 0.26 to 0.61, 0.10 to 0.37 mg kg−1, respectively. The Cd concentrations in leaves were higher than those in stems and roots. The highest Cd concentrations were in lower leaves, between 0.36 and 13.14 mg kg−1. In Yibin, the Cd in lower leaves nearly exceeded 10 mg kg−1 and the ratio of the Cd tobacco and soil concentrations (the bioconcentration factor, BCF) was 9.41. Path analysis showed soil pH and cation exchange capacity (CEC) were the most significant properties exhibiting direct effects on Cd accumulation. Stepwise multiple linear regression showed that soil Cd, pH, CEC and organic carbon (OC) were the major factors controlling Cd bioavailability to tobacco leaves, explaining more than 94.0% of the variance. The results are useful in predicting the transfer of Cd from soil to tobacco. [ABSTRACT FROM AUTHOR]

Street food business provides low-cost ready-made meals and employments for the marginal people in developing countries. But the lack of good hygiene in the street food shops is a major concern for consumer. This research examined the effect of the socio-demography of vendors and other factors on hygienic practices in street food shops. This cross-sectional study was conducted among 137 street food vendors in the Barishal and Patuakhali cities of Bangladesh. A pre-structured questionnaire was used to collect information on sellers and shops. A logistic regression model was employed to check the effect of the factors on the hygiene practice score of respondents. Among the vendors, only 27.7% recruited an extra employee in their shops and 43.1% had a good score on the hygienic practices. Regression analysis showed that vendors who completed secondary education (AOR = 3.308; 95% CI: 1.560 to 7.015) and recruited extra employee (AOR = 3.381; 95% CI: 1.465 to 7.800) were more likely to have a higher score than the counterparts. The overall hygiene practices of the vendors were not satisfactory. The education of sellers and the employee's assistance will boost the hygienic standards of the street food shops. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the spatio-seasonal variations in water quality and suitability of the Shitalakhya river, an economically important and ecologically critical urban river in Bangladesh, along with associated influencing factors and possible sources of water pollution. Therefore, surface water samples were collected monthly from five sampling sites, and fourteen water quality parameters were evaluated. The results showed that some studied water quality parameters, e.g., temperature, TDS, TA, TH, NO2–, and NO3–, exceeded the maximum allowable limit, whereas statistically significant (p <.05) variations were observed among pre-monsoon (February–May), monsoon (June–September), and post-monsoon (October–January) seasons. The values of water quality index (WQI) exhibited that the water quality was found to be very poor to unsuitable for drinking, fisheries, or aquatic environment. The principal component analysis (PCA) extracted two PCs explaining 91.092% of the total variance, which suggested that the variations in water quality are attributed mainly to point and nonpoint sources of contamination including municipal and industrial wastewater discharge, and agricultural runoff of inorganic fertilizers. The cluster analysis (CA) also showed relative spatial and seasonal variations in river water quality, indicating the influence of hydrological changes and pollution sources. The study revealed that the water of the Shitalakhya river is highly polluted and potentially hazardous for human uses, and thus more attention should be given to safeguard such an important urban river. [ABSTRACT FROM AUTHOR]

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 (Igeo), pollution load index (PLI), and contamination factor (Cif) 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. [ABSTRACT FROM AUTHOR]

Indigenous vegetables are available at low cost but there is little information about their nutritional composition. The study was conducted to compare the nutritional status of exotic and indigenous vegetables. Most indigenous vegetables contained more minerals than exotic vegetables. Potassium was the most abundant macro-element (135–746 mg/100 g) followed by phosphorus (16–98 mg/100 g). The most calcium was in leaves of Colocasia esculenta (L) (238 mg/100 g). The most magnesium (91 mg/100 g) and Vitamin-C (76 mg/100 g) was in Nymphaea nouchali (Burman) bulb, and Brassica oleracea (L), respectively. Regular consumption of indigenous vegetables may meet nutritional requirements in the human diet. [ABSTRACT FROM AUTHOR]

Heavy metals contamination is a serious threat for the toxicity and bioaccumulation in food chain. Aquatic environment contamination has become a global concern because they have toxic effects on fishes. The concentration of heavy metals like arsenic (As), chromium (Cr), cadmium (Cd) and lead (Pb) in commercially fishes (Tenualosa ilisha, Gudusia chapra, Otolithoides pama, Setipinna phasa, Harpadon nehereus, Polynemus paradiseus, Sillaginopsis panijus and Pampus chinensis) collected from Karnaphuli River in Bangladesh were (fish muscles) assessed with health risk during summer and winter season. These heavy metals are toxic in nature and can come to human food chain through fish consumption. The mean concentration of As, Cr, Cd and Pb was found 1.59, 0.73, 0.41 and 1.13 mg/kg in summer and 1.81, 0.92, 0.52 and 1.45 mg/kg in winter, respectively. Cr and Pb concentration of all fish species were found to be higher than Food and Agriculture Organization (FAO)/(WHO) tolerable concentration assuming these metal pose risk to human. The hazard quotients value of heavy metals in Harpadon nehereus was found higher than one resulting non-carcinogenic risk for consumption of this fishes. Carcinogenic risk value for As and Pb were remaining 10−6 to 10−4 indicating continuously consumption of studied fish samples may cause cancer risk. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This research was conducted to assess the concentration of six heavy metals ie, chromium (Cr), nickel (Ni), copper (Cu), arsenic (As), cadmium (Cd) and lead (Pb) in different foods associated with health hazard inference in Bangladesh. The range of Cr, Ni, Cu, As, Cd and Pb in food samples were 0.45–47.7, 0.22–38.6, 0.43–47.4, 0.72–6.05, 0.001–6.70 and 0.21–35.9 mg/kg, respectively. The estimated daily intake values of all the metals except Cu were higher than the maximum tolerable daily intake. The target hazard quotients of all metals were higher than 1 through consumption of cereal and vegetables, indicating significant health risks to both adult and children. The total carcinogenic risk (CR) of As (9.84E–01) was higher the threshold level (1.0E–06) and 9.84E–01 for Pb clearly revealed that consumption of these food items definitely poses cancer risks to the Bangladeshi population. [ABSTRACT FROM AUTHOR]

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 factorwere 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, thevalues 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. [ABSTRACT FROM AUTHOR]