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As a cereal crop, maize ranked third place after wheat and rice in terms of land area coverage for its cultivation, and in Bangladesh, it ranked second place after rice in its production. As the substitution of wheat products, maize has been used widely in baking for human consumption and animal fodder. However, maize grown in this soil around the coal-burning power plant may cause heavy metals uptake that poses a risk to humans. The study was conducted at the maize fields in the Ganges delta floodplain soils of Bangladesh to know the concentration of eight heavy metals (Ni, Cr, Cd, Mn, As, Cu, Zn, and Pb) in soil and maize samples using an inductively coupled plasma mass spectrometer (ICP-MS) and to estimate the risk of heavy metals in maize grains. Mean concentrations of heavy metals (mg/kg) in soil were in decreasing order of Zn (10.12) > Cu (10.02) > Mn (5.48) > Ni (4.95) > Cr (3.72) > As (0.51) > Pb (0.27) > Cd (0.23). The plant tissues showed the descending order of heavy metal concentration as roots > grains > stems > leaves. BCF values for As, Cd, Pb, and Mn in roots were higher than 1.0, indicating considerable accumulation of these elements in maize via roots. Total hazard quotient (ƩTHQ) of heavy metals through maize grain consumption was 3.7E+00 and 3.9E+00 for adults and children, respectively, indicating non-cancer risk to the consumers. Anthropogenic influences contributed to the heavy metals enrichment in the Ganges delta floodplain soils around the thermal plant, and potential risks (non-carcinogenic and carcinogenic) were observed due to the consumption of maize grain cultivated in the study area., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The degradation of the environment due to numerous industrial practices has emerged as a major issue globally, particularly in a country like Bangladesh. The present study dispenses information about heavy metal (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb) contamination in some frequently consumed vegetables, namely, ash pumpkin, potato, bitter gourd, buffalo spinach, snake gourd, and pointed gourd grown in an industrially prone location and their repercussion on consumers' health. Proton-induced X-ray emission (PIXE) technique was used as the major analytical tool to detect heavy metal concentrations. Mean concentration and the range of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb in vegetables were detected (4.81 ± 2.79, 2.43-10.94), (497.57 ± 258.08, 181.24-886.67), (644.49 ± 298.40, 179.56-998.78), (38.88 ± 14.31, 18.88-60.12), (58.11 ± 12.58, 42.55-84.79), (137.24 ± 48.37, 71.99-208.98), (123.31 ± 63.62, 49.97-256.09), (8.09 ± 2.69, 4.29-14.94), and (4.16 ± 2.95, 1.22-9.98) mg/kg (dry weight basis), respectively. An extreme level of heavy metal contamination in vegetable samples was notified regarding the estimated metal pollution index (MPI) and Nemerow pollution index (P) value, which underpinned the health risk values. The estimated hazard index (HI) value stipulated high risk in all varieties of vegetables regardless of age group and cadmium (Cd) was found as the major contributor. Concerning the carcinogenic risk index (CR) for single elements, the value of Co, Ni, and Cr was approximated far above the USEPA threshold risk limit (CR>1E-04). Moreover, total carcinogenic risk (TCR) for all varieties of vegetables exceeded the safety threshold value for both the age group and children, in particular, were found most vulnerable. The outshot of the present study divulged associated health risks for the population group by the heavy metals via dietary intake of vegetables., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

This study aims to assess seasonal and spatial variations, contamination status, ecological risks, and metal sources (Ni, Pb, Cr, Cu, Mn, and Zn) in human-afforested mangrove sediments in a deltaic region. Five sampling locations were sampled during dry and wet seasons. Heavy metal concentrations followed the order: Mn > Zn > Ni > Cr > Cu > Pb. Metal loads, except Cu and Pb, were higher during the dry season, aligning with national and international recommendations. Sediment quality guidelines, contamination factor, geoaccumulation index, enrichment factors, and pollution load index indicated uncontaminated sediment in both seasons. Potential ecological risk assessment showed low risk conditions in all sites. However, modified hazard quotient indicated moderate pollution risk from all metals except Pb. Analysis suggests anthropogenic sources, particularly evident near shipbreaking yards in Sitakunda. While initially uncontaminated, ongoing metal influx poses a potential risk to mangrove ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The widespread occurrence of heavy metals in aquatic environments, resulting in their bioaccumulation within aquatic organisms like fish, presents potential hazards to human health. This study investigates the concentrations of five toxic heavy metals (Pb, Hg, Zn, Cu, and Cr) and their potential health implications in two economically important fish species ( Otolithoides pama and Labeo bata ) from a subtropical estuarine wetland system (Feni estuary, Bangladesh). Muscle and gill samples from 36 individual fish were analyzed using energy dispersive X-ray fluorescence (EDXRF). The results revealed that the average quantities of heavy metals in both fishes' muscle followed the declining order of Zn (109.41-119.93 mg/kg) > Cu (45.52-65.43 mg/kg) > Hg (1.25-1.39 mg/kg) > Pb (0.68-1.12 mg/kg) > Cr (0.31-5.82 mg/kg). Furthermore, Zn was found to be present in the highest concentration within the gills of both species. While the levels of Cu, Zn, and Cr in the fish muscle were deemed acceptable for human consumption, the concentrations of Pb and Hg exceeded the permissible limits (>0.5 mg/kg) for human consumption. Different risk indices, including estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic or target risk (TR), revealed mixed and varying degrees of potential threat to human health. According to the EDI values, individuals consuming these fish may face health risks as the levels of Zn, Cu, and Cr in the muscle are either very close to or exceed the maximum tolerable daily intake (MTDI) threshold. Nevertheless, the THQ and HI values suggested that both species remained suitable for human consumption, as indicated by THQ (<1) and HI (<1) values. Carcinogenic risk values for Pb, Cr, and Zn all remained within permissible limits, with TR values falling below the range of (10 -6 to 10 -4 ), except for Zn, which exceeded it (>10 -4 ). The correlation matrix and multivariate principal component analysis (PCA) findings revealed that Pb and Cr primarily stemmed from natural geological backgrounds, whereas Zn, Cu, and Hg were attributed to human-induced sources such as agricultural chemicals, silver nanoparticles, antimicrobial substances, and metallic plating. Given the significance of fish as a crucial and nutritious element of a balanced diet, it is essential to maintain consistent monitoring and regulation of the levels and origins of heavy metals found within it.

Microplastics (MPs) as hazardous contaminants has drawn the rapid attention of the general public due to their omnipresence and adverse impacts on ecosystems and human health. Despite this, understanding of MPs contamination levels in the estuarine ecosystems along the Bay of Bengal coast remains very limited. This research focused on the presence, spatial distribution, morpho-chemical characteristics and ecological implications of MPs in water and sediment from five key estuaries (Meghna, Karnaphuli, Matamuhuri, Bakkhali, and Naf rivers) within the Bengal delta. Out of the five estuaries, the Meghna exhibited the least amount of MPs in both surface water (150.00 ± 65.62 items/m 3 ) and sediment (30.56 ± 9.34 items/kg). In contrast, the highest occurrence of MPs was recorded in Karnaphuli river water (350.00 ± 69.22 items/m 3 ) and Matamuhuri river sediment (118.33 ± 26.81 items/kg). ANOVA indicated a statistically significant distinction (p < 0.01) among the examined estuaries. Most identified MPs were fibers and < 0.5 mm in size in both water and sediment samples. Transparent MPs were dominant in both water (42.28%) and sediment (45.22%). Besides violet, red, blue, pink and green colored MPs were also observed. Various polymer types, including PE, PP, PET, PS, Nylon, EVA, and ABS, were detected, with PE being the dominant one. Based on the polymer risk index (PHI), the estuaries were classified as hazard level V, signifying a severe level of MP contamination. However, the potential ecological hazardous index (PHI), potential ecological risk index (RI), and pollution load index (PLI) indicated moderate pollution levels. This study offers initial insights into the pollution caused by MPs in major estuaries of Bengal delta, which policymakers can utilize to implement suitable management strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Microplastics (MPs) have gained a serious attention as an emerging contaminant throughout the world because of their persistence and possible risks to aquatic ecosystems and human well-being. However, knowledge on MPs contamination from sub-tropical coastal systems is limited, and no study has been conducted on the MPs contamination in sediment from one of the highest sediment-laden estuaries, Meghna River, in the world. This is the first study to examine the quantity, morpho-chemical characteristics and contamination risk level of MPs from this large scale river. MPs were extracted from the sediment samples of 10 stations along the banks of the estuary by density separation, and then characterized using a stereomicroscope and Fourier Transform Infrared (FTIR) spectroscopy. The incidence of MPs varied from 12.5 to 55 item/kg dry sediment with an average of 28.67 ± 10.80 item/kg. The majority (78.5%) of the MPs were under 0.5 mm in size, with fibers being the most (74.1%) prevalent MPs type. Polypropylene (PP) was found to be the predominant polymer (53.4%), followed by polyethylene (PE, 20%), polystyrene (PS, 13.3%), and polyvinyl chloride (PVC, 13.3%). The highest occurrence of PP indicted the MPs in the estuary might be originated from clothing and dying industries, fishing nets, food packages, and pulp industries. The sampling stations were contaminated with MPs as shown by the contamination factor (CF) values and pollutant load index (PLI), both of which were >1. This study exposed new insights on the status of MPs in the sediments of the Meghna River, laying the groundwork for future research. The findings will contribute to estimate the global share of MPs to the marine environment., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Bilal Ahamad Paray reports financial support was provided by King Saud University., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The identification and description of novel plastic forms, such as pyroplastics and plastiglomerates, in coastal areas raised several concerns in the field of plastic pollution. Under the growing literature in the field, the present study preliminarily reports the occurrence of novel plastic forms on Cox's Bazar beach, Bangladesh. The description of the novel plastic forms agrees with the literature, mostly consisting of lithic and biogenic elements within a synthetic polymer matrix (HDPE, LDPE, PP, and PET identified). Several knowledge gaps regarding the interaction between the novel plastic forms and colonizing organisms, as well as the leaching rates of plastic additives, remain to be addressed as crucial points to understand their implications. Illegal waste dumping and burning were identified as the primary catalysts for the emergence of new plastic forms in Cox's Bazar. Overall, researchers must reach a baseline consensus regarding the methodologies and next steps in the field., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Functioning of coastal wetland habitats is essential for the ecosystem integrity and sustainability of coastal development that enables human progress along transitional waterways. However, these habitats are continuously being affected by a variety of pollutants including metallic elements. In this study, seasonal variation, pollution status and ecological risks of heavy metals (Cr, Mn, Co, Ni, As, Cu, Zn and Pb) in surface sediment of the several types of coastal wetlands (estuaries, mudflats, sandy beaches, mangroves, and saltmarshes) were detected by using X-ray fluorescence (EDXRF) spectrometry. The results showed that the mean concentration level of metals in the surficial sediment samples followed the order of Cu (84.06 ± 8.60 μg/g) > Zn (51.00 ± 8.97 μg/g) > Mn (38.25 ± 11.34 μg/g) > Cr (3.52 ± 0.91 μg/g) > Pb (0.27 ± 0.13 μg/g) > Co (0.24 ± 0.13 μg/g) > As (0.21 ± 0.12 μg/g) > Ni (0.16 ± 0.08 μg/g). In comparison to the pre-monsoon period, the post-monsoon season had higher concentrations of heavy metals while the overall accumulation level of metals in the wetlands exhibited a pattern of estuarine wetland (28.47 ± 31.35 μg/g) > mangrove (22.23 ± 30.79 μg/g) > mudflat (21.79 ± 29.71 μg/g) > sandy beach (21.47 ± 28.15 μg/g) > saltmarsh (21.28 ± 30.02 μg/g). Although, the pollution assessment indices e.g., contamination factor (CF), degree of contamination (CD), geoaccumulation index (I geo ) and pollution load index (PLI) showed minimal levels of contamination in the studied sites, enrichment factor (EF) suggested greater enrichment of the metals in the pre-monsoon season but with the lowest ecological risk (RI < 40) in both seasons. Cluster analysis, principal component analysis (PCA), and Pearson's correlation were performed to determine the sources of heavy metals in collected samples which specified that Pb, As, Co and Ni predominantly came from natural sources whereas Cu, Mn, Zn and Cr emerged from anthropogenic sources such as industrial effluents, domestic wastewater, fertilizer or pesticide consumption on farmland along the riverbank, vessel emissions, and the confluence of tributary rivers., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Bilal Ahamad Paray reports financial support was provided by King Saud University., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Potentially toxic elements (PTEs) such as Hg, As, and Pb have become concentrated in the aquatic ecosystem as a result of increased human activities. However, these substances frequently have synergistic or antagonistic effects on the human body or other animals. As a result, there are concerns world-wide that commercially available food products, especially fish, may be contaminated with hazardous elements. In this study, samples of four selected fishes, Gutum ( Lepidocephalichthys guntea ), Baim ( Macrognathus pancalus ), Baila ( Glossogobius giuris ), Meni ( Nandus nandus ) were analyzed from one of the largest freshwater wetlands (designed as a Ramsar Site) in South Asia to evaluate PTEs contamination status and human health risk assessment. The result demonstrated that the degree of contamination for six PTEs decreased in the following sequences for fish: Fe > Zn > Cu > Pb > As > Hg. The edible part of G. giuris had the maximum value for Hg (0.42 μg/g dw), while N. nandus predominantly accumulated As (<0.41 μg/g dw). The estimated daily intake (EDI) values ranged from 0.003 to 1.75, which was much lower than the recommended values. The hazard index (HI), THQ, total target hazard quotient (TTHQ) scores through consuming fish followed the decreasing order of Fe > Hg > Cu > Zn > Pb. The values for each index were less than 1, indicating that there were no substantial health risks for the consumers. The carcinogenic risks (CR) derived from the intake of Pb ranged from 4.92 × 10 -8 to 4.14 × 10 -8 for males and 5.45 × 10 -8 to 4.59 × 10 -8 for females, which also did not exceed the standard limit (1.00 × 10 -6 ). This study demonstrated that, under the existing consumption rate, there was no potential health harm to consumers from consuming the studied fishes. This study offers a chance to regularly check PTEs in this environment, reducing the contamination of heavy metals.

Aquatic ecosystems are exceedingly contrived due to industrial dispenses, as a huge amount of toxicants especially heavy metals are released, causing drastic effects on aquatic lives and the human body. This study was performed to assess the quality of point-source industrial wastewater at varying percentage levels and their subsequent hazardous effect on fish (Anabas cobojius) and human health. The perceived value revealed that water quality parameters declined with the increase of wastewater concentration and trace metal evaluation index (TEI) ascertained a high level of water pollution due to Cr, Mn, Fe, Co, Ni, Cu, Zn, and As content for all percentages of wastewater. Concentration of wastewater and culture treatment duration largely impacted on fish mortality rate, body dis-pigmentation, mucus secretion rate, coagulation of mucus all over the body, and accumulation of heavy metals by fish samples. Metal pollution index (MPI) indicated low contamination of fish by the measured elements. Zn and Hg exceeded the threshold limit of target hazard quotient (THQ > 1) and contributed significantly to non-carcinogenic health implications for both the population group. Maximum hazard index in adults and children was observed to be 10.638 and 16.548 for 100% effluent at 96-h exposure period and the overall HI value manifested a very high to medium significant health effects regardless of age. Carcinogen Pb showed insignificant risk but Cr and Ni showed extremely high to medium-high risk for both the population group, and children were found more vulnerable receptors than adults. However, source of heavy metals in wastewater and fish samples stipulated anthropogenic sources., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Estuarine contamination by Microplastics (MPs) is a mater of serious concern since these areas offer the society valuable ecosystem, economic, and recreational services such as breeding and feeding ground for fish, carbon fixation, nutrients recycling and port development. The Meghna estuary, located along the Bengal delta coast, provides livelihoods for thousands of peoples in Bangladesh, and served as breeding ground for national fish, Hilsha shad. Therefore, knowledge and understanding on any kind of pollution including MPs of this estuary is essential. In this study, the abundance, characteristics and contamination assessment of MPs from the surface water of a Meghna estuary were investigated for the first time. The results demonstrated that MPs were present in all samples and the abundance ranged from 33.33 to 316.67 item/m 3 with a mean value of 128.89 ± 67.94 item/m 3 . Morphological analyses resulted in four types of MPs such as fibers (87%), fragments (6%), foam (4%), and films (3%) with the majority of these being colored (62%) and smaller (<0.5 mm) in size (88%). On the other hand, FTIR analysis for chemical characteristics confirmed five types of polymers, including polythene (PE), polystyrene (PS), polythene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC). The area was determined to be moderately to severely contaminated with MPs based on contamination factor (CF) values (6.18 ± 2.08 to 2.50 ± 1.0) and the pollutant load index (PLI) value (1.94 ± 0.33) as these values were > 3-6 for CF, and >1 for PLI. These results can be utilized to develop policy for the protection of this important environment., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mohammed Fahad Albeshr reports financial support was provided by King Saud University., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Contamination of fish species with potential toxic elements (PTEs) has caught the prime attention globally including Bangladesh. The present study enlightened on the accumulation, origin, and associated health implications of Mn, Fe, Cu, Zn, As, Hg, Pb, and Cr in ten varieties of fish species collected from the heavily polluted river Buriganga. Levels of PTEs in the studied fish species were found within the legislative value suggested by the World Health Organization (WHO) and Federal Environmental Protection Agency (FEPA) except for Fe, Cu, Zn, and Hg and can be assembled as Zn > Fe > Cu > Mn > Cr > Hg > As > Pb. The origin of PTEs in fish species apportioned mostly anthropogenic coupled with natural sources. Among the anthropogenic sources, industrial wastewater, recycling of leaded and lithium-ion batteries, metallurgical industries, shipyards, tannery, cosmetics, and chemical industries are the major contributors. This study identified children are exposed to As and Zn as their estimated targeted hazard quotient (THQ) value exceeded the threshold limit of safety, whereas adults are exposed to As only. The estimated, hazard index (HI) for children was found more than four times of adults; however, both the population groups are in vulnerable situation considering HI value (HI > 1), indicating possible non-carcinogenic health risk. Moreover, cumulative cancer risk TCR appraised that all the fish species exceeded the threshold limit of > 1E-03 for children and > 1E-04 for adults, which are level VII and level V contamination state for child and adult, respectively, and manifested consumption of the studied fishes arises a high probability for lifetime cancer risk., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The coastal zone of Bangladesh, with a population density of 1278 people per square kilometer, is under serious threat due to heavy metal pollution. To date, many studies have been conducted on the heavy metal contamination in soils, water, aquatic animals, and plants in the coastal zone of Bangladesh; however, the available information is dispersed. In this study, previous findings on the contamination levels, distributions, risks, and sources of heavy metals in sediments and organisms were summarized for the first time to present the overall status of heavy metal pollution along coastal regions. Earlier research found that the concentrations of various heavy metals (HMs), particularly Co, Cd, Pb, Cu, Cr, Mn, Fe, and Ni in water, sediment, and fish in most coastal locations, were above their permissible limits. High concentrations of HMs were observed in sediments and water, like Cr of 55 mg/kg and 86.93 mg/l in the ship-breaking areas and Karnaphuli River, respectively, in coastal regions of Bangladesh. Heavy metals severely contaminated the Karnaphuli River estuary and ship-breaking area on the Sitakundu coast, where sediments were the ultimate sink of high concentrations of metals. Sedentary or bottom-dwelling organisms like gastropods and shrimp had higher levels of heavy metals than other organisms. As a result, the modified PRISMA review method was used to look at the critical research gap about heavy metal pollution in Bangladesh's coastal areas by analyzing the current research trends and bottlenecks., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

As a precursor to risk assessment and risk management through consuming contaminated seafood, food safety needs to be quantified and assured. Seaweed is an increasing dietary component, especially in developing countries, but there are few studies assessing uptake rates of contaminants from this route. As such, the present study determined likely human uptake due to the trace elemental (Fe, Mn, Ni, Cu, Zn, Se, Hg, and As) concentrations in the edible red seaweeds (Rhodophyta) Gelidium pusillum and Hypnea musciformis, growing in the industrialised Cox's Bazar coastal area of Bangladesh. Metal and metalloid concentrations in G. pusillum were in the order (mg/kg): Fe (797 ± 67) > Mn (69 ± 4) > Ni (12 ± 5) > Zn (9 ± 4) > Cu (9 ± 4) >Se (0.1 ± 0.1) > Hg (0.1 ± 0.01), and in H. musciformis: Fe (668 ± 58) > Mn (28 ± 5) > Ni (14 ± 2) > Zn (11 ± 5) > Cu (6 ± 4) >Se (0.2 ± 0.03) > Hg (0.04 ± 0.01). Despite the industrial activities in the area, and based on 10 g. day -1 seaweed consumption, it is concluded that these concentrations pose no risk to human health as part of a normal diet according to the targeted hazard quotient and hazard index (THQ and HI) (values < 1). In addition, and as a novel aspect for seaweeds, Selenium Health Benefit Values (Se-HBV) were determined and found to have positive values. Seaweed can be used as an absorber of inorganic metals for removing contamination in coastal waters. The results are a precursor to further research regarding the efficiency and rate at which seaweeds can sequester metal contamination in water. In addition, management techniques need to be developed thereby to control the contaminant inputs., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Toxic metal pollution is a global issue, and the use of metal-accumulating plants to clean contaminated ecosystems is one of the most rapidly growing ecologically beneficial and cost-effective technologies. In this study, samples of sediment and three mangrove species (Excoecaria agallocha, Avicennia officinalis, Sonneratia apetala) were collected from the world’s largest mangrove forest (along the Northern Bay of Bengal Coast) with the aim of evaluating metal concentrations, contamination degrees, and phytoremediation potentiality of those plants. Overall, the heavy metals concentration in sediment ranged from Cu: 72.41−95.89 mg/kg; Zn: 51.28−71.20 mg/kg; Fe: 22,760−27,470 mg/kg; Mn: 80.37−116.37 mg/kg; Sr: 167.92−221.44 mg/kg. In mangrove plants, the mean concentrations were in the order of E. agallocha > A. officinalis > S. apetala. The mean (± SD) concentration of each metal in the plant tissue (root) was found following the descending order of Fe (737.37 ± 153.06) > Mn (151.13 ± 34.26) > Sr (20.98 ± 6.97) > Cu (16.12 ± 4.34) > Zn (11.3 ± 2.39) mg/kg, whereas, in the leaf part, the mean concentration (mg/kg) of each metal found in the order of Fe (598.75 ± 410.65) > Mn (297.27 ± 148.11) > Sr (21.40 ± 8.71) > Cu (14.25 ± 2.51) > Zn (12.56 ± 2.13). The contamination factor (CF) values for the studied metals were in the descending order of Cu > Sr > Zn > Fe > Mn. The values of Igeo (Geo-accumulation index) and CF showed that the area was unpolluted to moderately polluted by Zn, Fe, Mn, Cu and Sr. Enrichment factor (EF) values in both sampling stations portrayed moderate to minimum enrichment. Phytoremediation potentiality of the species was assessed by bio-concentration factor (BCF) and translocation factor (TF). BCF values showed less accumulation for most of the heavy metals (<1) except Mn which was highly accumulated in all mangrove plants. The translocation factor (TF) values depicted that most of the heavy metals were strongly accumulated in plant tissues (>1). However, the BCF value depicts that Mn was highly bioconcentrated in E. agallocha, but the translocation on leaves tissue were minimum, which reveals that E. agallocha is phytoextractor for Mn, and accumulated in root tissues. All the examined plants can be used as phytoextractors as they have bioconcentration factors <1 and translocation factors >1. However, A. officinalis is clearly more suitable for metal extraction than S. apetala and E. agallocha in terms of hyper-metabolizing capabilities.

In this study, we combined atmospheric pressure cold plasma, a novel treatment technology, with an absorption technique with soybean husk to remove Pb and Cd from milk. Different combinations of treatment duration, voltage, and post treatment retention time were used to determine the effectiveness of cold plasma. Soybean husk was used for metal extraction, and it was observed that when the milk samples were plasma treated with a discharge voltage of 50 kV for 2 min and held for 24 h, the highest mean elimination of about 27.37% for Pb and 14.89% for Cd was obtained. Reactive oxygen and nitrogen species produced from plasma treatment were identified using Optical Emission Spectra analysis. A high voltage of 50 kV plasma for a 2 min duration could produce 500 ± 100 ppm of ozone concentration inside the treated package. The value of ΔE, which indicates overall color difference measurement, was significantly (p < 0.05) higher in all the treated samples than control samples. However, in the frequency range from 0.01 to 100 Hz, there was not much difference between the control and treated sample in the frequency sweep test. The identified functional groups at different wavenumbers (cm−1) in the treated samples were found to be similar compared to the control samples.

Heavy metal (HM) contaminated soil can affect human health via ingestion of foodstuffs, inhalation of soil dust, and skin contact of soil. This study estimates the level of some heavy metals in soils of industrial areas, and their exposures to human body via dietary intake of vegetables and other pathways. Mean concentrations of Cr, Fe, Cu, Zn, As and Pb in the studied soil were found to be 61.27, 27,274, 42.36, 9.77, 28.08 and 13.69 mg/kg, respectively, while in vegetables the respective values were 0.53, 119.59, 9.76, 7.14, 1.34 and 2.69 mg/kg. Multivariate statistical analysis revealed that Fe, Cu, Zn, and Pb originated from lithogenic sources, while Cr and As are derived from anthropogenic sources. A moderate enrichment was noted by Cr, As, and Pb in the entire sampling site, indicating a progressive depletion of soil quality. The bioaccumulation factor (BCF) value for all the vegetables was recorded as BCF < 1; however, the metal pollution index (MPI) stipulates moderately high value of heavy metal accumulation in the vegetable samples. Hazard Index (HI) of >0.1 was estimated for adults but >1 for children by direct soil exposure, whereas HI < 1 for both children and adults via dietary intake of vegetables. Estimated Total carcinogenic risk (TCR) value due to soil exposure showed safe for adults but unsafe for children, while both the population groups were found to be safe via food consumption. Children are found more vulnerable receptors than adults, and health risks (carcinogenic and non-carcinogenic) via direct soil exposure proved unsafe. Overall, this study can be used as a reference for similar types of studies to evaluate heavy metal contaminated soil impact on the population of Bangladesh and other countries as well.

Particle-induced X-ray emission (PIXE) method was used in this present research to identify the elements present in selected vegetable samples to show the possible influence in the metal absorption by the vegetables grown in a saline region of Rampal area of Munshiganj District, Bangladesh. The data acquisition setup is calibrated using a 2.5-MeV proton beam in the current ranges of 5nA to 15nA. The detector was used to measure the X-rays emitted during the irradiation. Data acquisition system MAESTRO-32 was used to measure the spectrum picks, and concentration calculation has been done by GUPIX/DAN-32 software. The purpose of this study is to determine the concentration of heavy and trace elements in these samples and to give current information on their safety for consumption. The result shows that K, Ca, and Fe have the highest concentrations, while lead exhibits the lowest but alarming rates compared to reference materials. The findings were likened to IAEA-V-10, IAEA-359, SRM 1515 (apple leaf), and SRM 1573a (tomato leaf). The outcomes of the present investigation demonstrate that these samples are not devoid of health risks in intake., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The focus of this study was to determine the depth-wise variability of physicochemical properties (i.e., pH, TOC, TN, and EC), and heavy metals (i.e., Pb, Cu, Zn, As, and Cr) concentration, and the associated biological and ecological risks of the mangrove sediment. The accumulation of metal contents and the phytoremediation and phytoextraction were also investigated in a mangrove species, Acanthus ilicifolius. The mangrove sediment consists of a higher proportion of sand fraction (56.6-74.7%) followed by clay (10-28%) and silt (10.1-15. 7%) fractions. The concentrations (mg/kg) of Pb, Cu, Zn, As, and Cr were ranged from 22.05-34.3, 8.58-22.77, 85.07-114, 5.56-12.91, and 0.98-5.12 in all the sediment layers. The hierarchy of the mean metal concentration in sediment was Zn (102 mg/kg) > Pb (25.6 mg/kg) > Cu (14.8 mg/kg) > As (8.79 mg/kg) > Cr (2.74 mg/kg) respectively. The examined metal concentrations were below the respective average shale values (ASVs). The degree of environmental, ecological, and biological risks was minimal according to various pollution indices like geoaccumulation index (I geo ), contamination factor (CF), and pollution load index (PLI). According to sediment quality guidelines (SQGs), the adverse biological risk effect was not likely to occur. The result of the potential ecological risk index (PERI) demonstrated that the study area was in the low-risk condition as the corresponded RI value < 100. A combined influence of geogenic and anthropogenic factors was identified as the metal sources by multivariate analysis. The study found that the accumulation rate of the metal contents was higher in leaves than that of roots. The mean descending metal concentration values were Zn (107) > Pb (28. 7) > Cu (16.9) > As (11.2) > Cr (4.99) in leaves and Zn (104.32) > Pb (27.02) > Cu (15.29) > As (10.39) > Cr (3.80) in roots. The translocation and bioaccumulation factors of heavy metals suggested that the mangrove plant species, A. ilicifolius can be used for phytoremediation and phytoextraction since the bio-concentration factor and translocation factor > 1. The studied species exhibited the metal tolerance associated with two following strategies, metal exclusion, and metal accumulation. However, excess metal tolerance can impact the surrounding marine environment., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Assessment of elemental contamination is emerging research in the present world. Metals are hazardous to the environment and people's health when metals concentration might exceed the tolerable level. In this research, 12 elements (i.e., Mn, Ni, Cu, Zn, As, Se, Sr, Co, Pb, Fe, Rb, and Ti) were assessed using the energy dispersive X-ray fluorescence (EDXRF) method in water and sediment samples in four (4) different spawning grounds of Tenualosha ilisha at the confluence of the Meghna River in Bangladesh. A comparative analysis was performed for the first time among four sampling spots, i.e., Chandpur, Bhola, Sandwip, and Hatiya, assessed all possible risk indices-it is a unique thing. Several risk indices were solved to determine the degree of sediment pollution for all 12 elements, e.g., degree of contamination (C d ):6.5-7.01, the modified degree of contamination ( m C d ): approximately 0.7, the pollution load index (PLI): 0.45-0.51, etc. where all the indices' results showed low or baseline levels of pollution. According to the enrichment factor (EF) computation, slight enrichment of examined metals except Pb and Zn was found. In addition to these, the ecological risk factor (E r ) found in the following order (pollution level: low): Cu > Pb > Zn among the four stations. Moreover, a spatial incline of metal accumulation was observed among the four spots: Bhola < Sandwip < Hatiya < Chandpur based on the risk index (RI) set value. However, a strong positive correlation (p < 0.05) between Ca and Fe, Ti and Fe, Ti and Mn, Mn and Fe, Fe and Sr were observed while Ca, and Co were strongly negatively correlated (r = minus (-)0.60, p < 0.05). The cluster analysis was performed and got an asymmetrical cluster among the sampling stations. This study recommends assessing the heavy metal concentration in biological samples, particularly in Hilsha fish., Competing Interests: The authors declare no conflict of interest., (© 2021 The Author(s).)

Although coastal water marine algae have been popularly used by others as indicators of heavy metal pollution, data within the Bay of Bengal for the estuarine Cox's Bazar region and Saint Martin's Island has remained scarce. Using marine algae, the study herein forms an effort in biomonitoring of metal contamination in the aforementioned Bangladesh areas. A total of 10 seaweed species were collected, including edible varieties, analyzed for metal levels through the use of the technique of EDXRF. From greatest to least, measured mean metal concentrations in descending order have been found to be K > Fe > Zr > Br > Sr > Zn > Mn > Rb > Cu > As > Pb > Cr > Co. Potential toxic heavy metals such as Pb, As, and Cr appear at lower concentration values compared to that found for essential mineral elements. However, the presence of Pb in Sargassum oligocystum species has been observed to exceed the maximum international guidance level. Given that some of the algae species are cultivated for human consumption, the non-carcinogenic and carcinogenic indices were calculated, shown to be slightly lower than the maxima recommended by the international organizations. Overall, the present results are consistent with literature data suggesting that heavy metal macroalgae biomonitoring may be species-specific. To the best of our knowledge, this study represents the first comprehensive macroalgae biomonitoring study of metal contamination from the coastal waters of Cox's Bazar and beyond., (© 2021. The Author(s).)

Chicken is one of the major protein sources and more affordable for the population of Bangladesh. Its quality monitoring is of high priority for food safety and public health risk assessment. This study determined metals (Fe, Cu, Zn, As, Ni, Cr, Sr, Hg, and Pb) in chickens from different farms of a high production area of Dhaka, Bangladesh, using an energy-dispersive X-ray fluorescence spectrometer to calculate the health risk through chickens consumption. In most cases, the toxic metals (As, Ni, Cr, Hg, and Pb) showed very high concentrations in different parts of chickens, especially livers that contained several times higher concentrations than the maximum allowable concentration (MAC). Analytical results showed some feed and water contain high concentrations of As and Cr that might be bioaccumulated in chicken. The estimated daily intake (EDI) for all metals was below the provisional tolerable daily intake (PTDI) values except As and Fe in few farms. Target hazard quotients (THQs) for most metals were less than 1 but THQs of As and Cr of few farms were higher than 1, indicating that the consumer would possess As- and Cr-based health hazards. Total target hazard quotient (TTHQ) of 42% for composite and 36% for body parts samples were > 1, suggesting potential health risk. The probabilistic risk and individual samples cancer risk (TR) were exceeded the acceptable level (10 -4 ) for As and 75% of composite and 58% of body parts of chicken showed acceptable limit (10 -6 to 10 -4 ) for Pb, indicating that the peoples might be exposed to lifetime cancer risk in the long run., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study was carried out to characterize the biogeochemical and physicochemical properties of landfill leachate from Matuail Sanitary landfill site, Dhaka, Bangladesh. In addition, the study also aimed to identify the photodegradation of landfill leachate under natural sunlight. The leachate pH was slightly alkaline (7.87-8.07) with a minimum level of dissolved oxygen, and low BOD 5 /COD ratio that are indicators of the matured methanogenic phase. Ca, Fe, Br, Rb, Cu was present in a considerable amount. A trace amount of Sr, Co, As, Pb, Cr was found in the leachate sample. Fourier Transform - infrared (FTIR) spectra of all three samples had five major peak regions notably at 3440-3450 cm -1 (O-H groups of water), 1638 cm -1 (C=O Amide I, carboxylates C=C, aromatic ring modes, or alkenes), 1385-1390 cm -1 (deformation of the C-H bond in CH 2 and CH 3 , or the asymmetric stretching of COO¯), 1115 cm -1 (stretching of the C-O bond in phenol ethers and phenols) and 605 cm -1 (S-O bends of sulfates). In addition to the appearance of new peak, peak shifting on the 2 nd -day and 5 th -day phototreatment are in compliance with the 34% TOC reduction. From analyzing three-dimensional excitation/emission (3D-EEM) spectra of the raw sample pyrene-like or humic-like peak A (Ex 255/Em 465), soil fulvic-like peak M p (Ex 315/Em 450), and humic-like peak C (Ex 370/Em 455) was found indicating more humified characteristics of the mature landfill site. From 1-hour to 6-hours phototreatment, all three substances slightly lost fluorescence intensity. From the 2 nd day to the 5 th day of photo-treatment, two unknown photo-product was identified within Ex 210/Em 457 and Ex 205/Em 408 at peak A region. Fluorescence intensity lost was 65% for peak A and 44% for peak C. Soil fulvic-like peak M p was absent on the 5 th day of photo-treatment., Competing Interests: The authors declare no conflict of interest., (© 2021 The Authors.)

In industrial areas, increased human activities generate high emissions of metals that contaminate the environment, and eventually affect human health. Therefore, this study aims to investigate the sources of toxic elements in indoor dust samples, and to evaluate possible health risks due to expose of human body through dermal contact, inhalation, and ingestion. A total 36 indoor dust samples were collected from the windows of twelve (12) industrial buildings, which are facing the main roads in the biggest export process zone (DEPZ) in Dhaka City, Bangladesh. The indoor dust samples were analyzed using X-ray fluorescence (XRF) technique for the determination of Cu, Zn, As, Pb, Fe, Cr, Co, Ni, K, Ca, Ti, Rb, and Sr. This investigation revealed that Cu, Zn, Pb, Fe, and Sr concentrations were slightly higher in various degree than that of the background value in soil recommended by the Chinese Environmental Protection Administration (CEPA). Subsequently, ANOVA (α = 0.05, p < 0.001) test and %RSD values (33% to 168%) showed that the concentrations of these metals were present non-homogeneously in different sampling points. However, statistical analysis and several geochemical indices have been proposed that these heavy metals might be come in indoor dust samples because of anthropogenic events. This investigation also showed that the most-extreme permissible hazard index (HIs) levels known as non-cancer risk for As, Mn, and Zn because of dust exposure in the study area were below than that of the safe limit (HI = 1) but with an exception of Pb (HI = 1.9E+00) for children. On the other hand, the degree of cancer-causing risk linked with exposure to arsenic in indoor dust (i.e., 0.502E-06 to 0.121E-05) falls within the range of threshold values (10 -6 to 10 -4 ). Therefore, following USEPA health risk models, it has been suggested that these metals present in indoor dust samples might not have significant impact on causing non-cancer and cancer risk to children and to adult at this moment in the DEPZ area, Bangladesh. However, a continuous monitoring should be needed to assess more accurately the non-cancer and cancer risk to children and adult., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

As a cheap source of high-quality protein, healthy fats and essential nutrients, dried fish is a common item in the daily diet of the Bangladesh populace. In this study, ten types of widely consumed dried fish (H. neherius, T. lepturu, P.chinensis, P. affinis, A. mola, P. microdon, I. megaloptera, C. dussumieri, L. calcarifer, and G. chapra) were analyzed for Cr, Mn, Fe, Co, Cu, Zn, Se, Rb, Hg, Pb, Ni and As by using an Energy Dispersive X-ray Fluorescence (EDXRF) technique. The concentration of the studied metals was found in the order Fe > Zn > Hg > Cu > Se > Cr > Mn > Co > Rb > Pb, while As and Ni were below the limit of detection. All fish species showed moderate to high pollution, where the species H. Neherius and P. Chinensis are the most and least polluted ones, respectively. The probable source of contamination is the leaching from the drying pans into the fish samples, atmospheric deposition, anthropogenic contamination, etc. of the water body where these fish were harvested. The calculated hazard index for the general population was below the maximum limiting value (i.e., < 1) except for Hg to children. The carcinogenic risk showed values lower than the acceptable limit for cancer risks (10 -6 to 10 -4 ). Periodic monitoring of trace metals in the aquatic organisms along with fish is recommended to avoid any unexpected health hazards caused by the toxic heavy metals via fish consumption., (© 2021. The Author(s).)

Studies from around the world have suggested salt marshes or coastal wetlands can be used as sites for phytoremediation of metals. However, no investigations have been conducted to assess metal accumulation and translocation capabilities of salt marsh macrophytes from Bangladesh coastal area. The aim of this study was to evaluate the uptake and translocation of eight metals, Fe, Zn, Mn, Cu, Co, Rb, Sr, and Pb in Porteresia sp. from the six salt marsh sites of Bangladesh. The leaf, shoots and root tissues of Porteresia sp. samples were analyzed for metals by using the energy-dispersive X-ray fluorescence (EDXRF). The decreasing trend of metal concentrations was, in roots; Fe > Mn > Pb > Cu > Zn > Sr > Rb > Co, in shoots; Mn >Fe > Cu > Pb > Zn > Sr > Rb > Co, in leaves; Fe > Mn > Cu > Pb > Zn > Rb > Sr > Co. Generally, roots of the Porteresia sp. showed high accumulation of the metals when compared to shoots and leaves suggesting relevant availability in the sediment. Pb was the only metal with concentrations significantly higher in the leaves and shoots than in the root. Except for Pb, bioaccumulation concentration factor (BCF) for all metals was lower than 1 in plant organs indicating poor absorption and bioavailability of metals. Higher value (>1) of BCF for Pb infers the species can potentially be used for Pb phytoremediation. However, the translocation factor (TF) confirmed the diversified mobility of the metals from below-ground part to above-ground parts for all the measured metals in the salt marsh species. Highest mobility was observed for Mn and Pb. But it was hard to find any regular trends among all the metals and all the sites., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Meghna River Estuary, the largest estuarine system (GBM, Ganges-Brahmaputra-Meghna) in Bangladesh, is a major spawning ground of national fish, Hilsha shad. In this study, we collected 24 surface sediment and 24 water samples from the entire lower estuary (4 sites, 3 sampling points from each site, 2 replicas from each sampling point) to detect trace/heavy metals. Sediment samples were collected from the top surface soil (0-5 cm) using Ekman grab sampler and water samples from 5 cm below the surface layer using plastic water bottles. After collection, sediment and water samples were preserved as necessary using HNO 3 (for water). Immediately after reaching the laboratory, sediment samples were dried in an oven at 70°C until the constant weight gained. The metals were then analyzed using energy-dispersive X-ray fluorescence method (EDXRF) and calculated the metal concentrations. In total, 12 metals were detected and the average value (mg/Kg) of all metals for sediment samples followed the descending order of Fe > Ca > K >Ti >Sr >Zr >Rb> Cu > Zn >Pb >As > Ni, and for water the order (µg/mL) of Fe >Ti > Ca > Co >Mn > Ni > Zn >Sr > Cu > As > Se . Besides, several physicochemical parameters i.e. water pH, soil pH, temperature, salinity, dissolved oxygen, hardness, and alkalinity of the 12 sampling points were also measured in-situ using handheld instruments., Competing Interests: There is no competing interest., (© 2020 The Author(s).)

Contaminants in road dusts can directly pose significant human health risks through oral ingestion, particle inhalation, and dermal contact. Therefore, this study has been designed to analyze heavy metal contaminations in 88 street dusts collected from the 22 high traffic sites and industrial areas of the Southeast Asian Megacity: Dhaka (capital of Bangladesh) using energy dispersive X-ray fluorescence (EDXRF) spectroscopy. This study revealed that the maximum Pb, Cd, Zn, Cr, Ni, As, Mn and Cu contents in the street dust samples were 18.9, 11.6, 239.2, 144.3, 37.1, 8.1, 261.5 and 49.6 mg/ kg respectively in which Ni and Pb concentration were 2 times, and Cd concentration was 200 times higher than the background level in soil; and As concentration was slightly higher than soil background level. The spatial distribution of heavy metal concentrations in street dust samples in Dhaka City was revealed that the hot spot areas of Pb, Ni, Cd and As were mainly associated with heavy traffic and industrial activities. The risk assessment strategies were used for this study for identifying the routes of exposure through oral ingestion, inhalation, and dermal contact by the fine particles (~75 μm) of street dust, especially for children based on the US EPA health risk models. Both non-carcinogenic and carcinogenic risks of heavy metals were characterized in street dust samples. Results based on the hazard index (HI), in the case of non-cancer effect, the ingestion of dust particles of children and adults in Dhaka City appeared to be the route of exposure to street dust that results in a higher risk for heavy metals, followed by dermal contact. This study revealed that the inhalation of re-suspended particles through mouth and nose were almost negligible. It was also noticed that children were experiencing the potential health risk due to HI for Cr (1.04), which was slightly higher than the safe level 1, and Cd (0.69) was close to the safe level 1. Reversely, cancer risk for Cr (i.e. 4.27 × 10 -6 ) was fallen within the range of threshold values (10 -4 to 10 -6 ) and As (i.e. 9.59 × 10 -7 ) was close to the upper limit of threshold values (10 -4 to 10 -6 )., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Samples for sediment and two species of native mangrove plants were collected from seven sampling sites for assessing the level of metal contamination. Results of the studied metals displayed the order of pollution as Fe > Ti > Zr > Rb > Zn > Sr > Pb > Y > Cu > Cr > As accordingly. Geoaccumulation index and contamination factor revealed that the sediment samples were unpolluted to moderately polluted by Zn, Fe, Ti, Rb, Y, and Zr. Ecological risk factor depicted a pollution-free condition in the study areas. PCA, CA, and correlation coefficient indicated that the source of the metals in the environment was anthropogenic. Bioconcentration factor values were found to be below 1 in both plant species. Conversely, transfer factor values for most heavy metals were found to be >1 in both plant species, which reflects the phytoremediation ability of plants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

It is considered that cow's milk is almost complete food for human as it provides most of the micronutrients and macronutrients. The cow's milks are essential for the growth and development especially for children. The main compositions of cow's milk are protein, fat, carbohydrates, vitamins and minerals which are well defined. Presently, the study of micronutrients and toxic elements in cow's milk has been widely carried out particularly in the industrialized and polluted regions because of its possibility of contamination, and thereby health risk of the consumers. The elemental composition in local cow's milk samples in Bangladesh is not well studied yet. The present study was therefore aimed to determine the level of heavy metals (Cr, Ni, As, Cd, Hg, Pb, Mn, Cu, Zn and Fe) in cow's milk using EDXRF technique. Subsequently, the experimental data was used to calculate the human health risk through the intake of both powder and liquid cows' milk available in Bangladesh. The results showed that powder milk contains significantly higher concentration of heavy metals than liquid milk samples. The HRI (health risk index) and HI (hazard index) values for most of the elements in all milk samples were within the safe limit (<1.0) or close to safe limit (≤1.0) with an exception of Hg. However, HRI value for Hg in powder milk samples for both children and adult showed a value higher than one (>1). MPI (metal pollution index) value for powder milk samples are very high compared to other type of milk samples analyzed in this study. Therefore, it has been suggested that heavy metal contamination through local powder milk samples might have significant negative impact (threat) on human health.

An assessment of the dietary risk of heavy metal exposure to humans is important since it is the main source of exposure. This study aimed to estimate the degree of contamination and assess the probable health risk in the prawn food chain. In prawn feed, the concentrations of metals were detected in the following order: Hg > Co > Pb > Cd. The concentrations of heavy metals in prawn were the highest for Co and lowest for Cd. Trace amounts of As and Cr were detected in the analyzed sample. Target hazard quotients for heavy metals for adults were >1 for Pb, Cd, Hg, and Co, and for children, the same were high for Co and Hg, indicating significant health risks upon dietary exposure. All the prawn samples contained nine-fold and fourteen-fold higher concentrations than the maximum acceptable levels for Pb and Hg, respectively (0.5 mg kg -1 ; WHO/FAO). Human health risk due to the Co exposure is quite alarming as the level of exposure was found to be very high. In the prawn samples intended for human consumption, the hazard index (HI) was highest in the samples obtained from Bagerhat (3.25 in flesh and 3.26 in skin), followed by the samples obtained from Satkhira (2.84 in flesh and 3.10 in skin) and Dhaka City Corporation (2.81 in flesh and 3.42 in Skin); this indicates a potential risk of prawn consumption obtained from Southeast Bangladesh. This is particularly problematic as this area accounts for the majority of prawn production and export of the country., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

To study the compositional trends associated with the spatial and layer wise distribution of heavy metals as well as the sediment response towards the untreated chemical wastes, we have analyzed river (Buriganga, Bangladesh) sediments by instrumental neutron activation analysis (INAA) and energy dispersive X-ray fluorescence (EDXRF). In nine sediment samples 27 elements were determined where Na, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Zn, As, Rb, Cs, La, Ce, Sm, Dy, Hf, Th and U were determined by INAA and Cu, Sr, Ba, Hg and Pb were determined by EDXRF. Pollution level and the origin of pollutants were evaluated by the aid of geo-accumulation index (Igeo), enrichment factor (EF), pollution load index (PLI) and the inter-element correlation analysis. Major elements are somehow buffered even though the pollution level is severe while the trace metals seem to be highly responsive. Among the heavy metals, Cr is the dominant pollutant, though the pollution level varies systematically with the sampling depth and the distance from the contamination source. Positive linear correlation between Cr and Zn (0.94) ensures the similar anthropogenic source(s) for these two metals, but the sediments of this study respond differently depending upon their geochemical behavior. Rare earth elements (here La, Ce, Sm and Dy), Th and U seem to have crustal origin and the Th/U ratio varies from 2.58 to 4.96., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Although the tobacco production and consumption rate in Bangladesh is very high and a substantial portion of premature deaths is caused by tobacco smoking, the status of heavy metals in tobacco plants has not yet determined. This study, therefore, investigated the concentrations of Cu, Ni, Cd, Pb, Cr, and Zn in tobacco plants and their surrounding agricultural soils in Kushtia District, Bangladesh. The geochemical maps showed a similar spatial distribution pattern of the analyzed metals and identified Shempur, Kharara, Taragunia, and Shantidanga as metal hot spots. Geoanalytical indexes were applied to assess the extent of soil contamination, and the results depicted that the soils of Shempur, Kharara, Taragunia, and Shantidanga were moderately contaminated where Cd contributed the most to contamination degree (C d) in spite of its relative low content. However, other five areas in Kushtia District were suggested as uncontaminated according to both C d and pollution load index (PLI). The hazard quotient (HQ) and hazard index (HI) showed no possible indication of human health risks via ingestion of agricultural soils. This study also determined that human activities such as excess application of commercial fertilizers, animal manures, and metal-based pesticides were the sources of Cu, Ni, Cd, and Cr enrichment in soils and that the metals into tobacco plants were transported from the soils. The present study conclusively suggested that regulation of improper use of agrochemicals and continuous monitoring of heavy metals in tobacco plants are needed to reduce the tobacco-related detrimental health problems in Bangladesh.

The concentrations of Cr, Cd, Pb, Hg, and As in water, poultry meat, fish, vegetables, and rice plants obtained from the area adjacent to the Hazaribag tannery campus, Dhaka, Bangladesh, were estimated and compared with permissible levels established by the WHO and FAO and levels reported previously by other authors. The metal contents were in the following order according to the concentration in contaminated irrigation water: Cr > Pb > As > Hg > Cd. Mean concentrations of Cr, Pb, Hg, and As in irrigated water were above the permissible levels, whereas the results were below the permissible levels for Cd. The metal concentrations in poultry meat, fish, rice, and vegetables were in the following orders: Pb > Cr > Cd > Hg > As, Pb > Cr > Cd > As > Hg, Pb > As, and Cr > Pb > Cd > As > Hg, respectively. The mean concentrations of metals in poultry meat, fish, rice, and vegetables were much higher than the permissible levels. The trends of weekly intake of heavy metals (WIMs) from poultry meat, fish, rice, and vegetables were as follows: Pb > Cr > Cd > Hg > As, Pb > Cr > Cd > As > Hg, Pb > As, and Cr > Pb > Cd > As > Hg, respectively. WIMs for all the metals were lower than the provisional maximum weekly intake recommended by WHO/FAO and USNAS.

Metal contamination in agricultural soils is of increasing concern due to food safety issues and potential health risks. Accumulation of Heavy and trace metals in vegetables occur by various sources but soil is considered the major one. Consumption of vegetables containing (heavy/trace) metals is one of the main ways in which these elements enter the human body. Once entered, heavy metals are deposited in bone and fat tissues, overlapping noble minerals and cause an array of diseases. The present study aimed to investigate the concentration of different metals in agricultural soil and vegetables grown on those soils and to evaluate the possible health risks to human body through food chain transfer. Contamination levels in soils and vegetables with metals were measured and transfer factors (TF) from soil to vegetables and its health risk were calculated accordingly. Results showed that concentration of Si, Ba, K, Ca, Mg Fe, Sc, V, Cr, Cu, Zn, As, Mn, Co, Ni, Se, Sr, Mo, and Cd in soil is higher than the World Average value and Al, Ti and Pb is lower than the World Average value whereas concentration of toxic elements like As, Co, Cu, Mn, Pb, Se, Ni, V and Zn in vegetable samples are below the World Average value. The intake of toxic metals (Fe, Cu, Mn, Zn Co, Cr, V, Ni, Pb and Cd) from vegetables is not high and within the permissible limit recommended by WHO, Food & Nutritional Board and US EPA. The Hazard Quotient (HQ) for Fe, Cu, Co, Cr, V, Ni, Pb, Mn, Zn and Cd were calculated which showed a decreasing order of Cd>Mn>Zn>Pb>Cu>Fe>Ni>V=Co>Cr. Highest HQ value found for Cd (2.543) which is above the safe value.