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The water bodies in Bangladesh thrive from plastic pollution. Estuaries are pools of environmental contaminants, and the world's largest mangrove forest, Sundarbans' estuary, is no exception. Thus, for the first time, we investigate MPs abundance in the muscle and gastrointestinal tract (GIT) of twenty estuarine species of fish and shellfish of the Sundarbans, as well as the human health risk. MPs abundance was evident in all the samples ranging from 5.37 ± 1.07 to 54.30 ± 16.53 MP items/g wet body weight (dw) in muscle samples and 7.33 ± 1.89 to 205.61 ± 136.88 MP items/g (dw) in GIT samples. The estimated health risk from MPs is substantial, where the average human intake will be 85,710.08 items of MPs per year per capita for the population of Bangladesh. The dominant polymer types observed using ATR-FTIR are PP and PE (17.5 %), PA (17.5 %) in the muscle tissues, and PP and PE (11.11 %), and EVA (11.11 %) in the GITs. Bottom-feeding species, such as demersal and benthic species, are more contaminated. However, the level of MPs in the species shows a negative correlation with the length and weight of the species. This study reveals that MP pollution is widespread and concerning in Bangladesh's Sundarban mangrove estuarine zone.

Current work focus on microplastic (MPs) occurrence in the water, sediment, and aquatic species (fish, crab, and snail) of the Buriganga River, Bangladesh, with an ecological risk assessment perspective. It also includes the distribution of MPs in different river ecosystem segments and the presence of heavy metal (loid)s (HMs) in water, sediments, and MPs surface. The MPs were inspected by stereomicroscope to identify the shapes, color, and size, and Fourier transform infrared (FTIR) spectroscopy was used to characterize polymer types. The samples concentration of four HMs viz., As, Cd, Cr, and Pb were determined by atomic absorption spectrometry (AAS). The possible MPs content in water, sediment, fish, crab, and snail were varied from 0.250 to 0.117 MPs/mL, 3.5-8.17 MPs/g, 0.65-3.82 MPs/g, 3.75-4.28 MPs/g, and 0.84-1.12 MPs/g, respectively. Fibers and fragments were the most dominant shape, less than 0.5 mm was dominant in size, and blue was the dominant color. In the evaluation of the chemical composition of MPs in water, sediment, fish, snail, and crab samples, Polyethylene terephthalate (PETE), Ethylene-vinyl acetate (EVA), High-density polyethylene (HDPE), Acrylonitrile butadiene styrene (ABS), Cellulose acetate (CA), and Nylon were identified. Regarding HMs load, the river demonstrated a highly polluted environment following the abundance pattern CrPbAsCd. SEM-EDAX of MPs was conducted to investigate the surface MP's surface and elemental composition. It reveals that the MPs surface has characteristic flakes, cracks, and adhering particles along with Si, K, Au, C, and O on the surface studied MPs. There is no significant relationship found among the ecosystem segments. However, Ompok bimaculatus species show a negative relationship of MPs distribution with water and sediment. Moreover, according to the ecological risk of MPs pollution in the Buriganga River, it was in category-I, indicating considerable pollution load due to the presence of MPs.

Groundwater contaminated with arsenic is a significant environmental health concern worldwide because of the potential health risk due to ingestion of agricultural products produced to irrigate arsenic-contaminated water. Besides arsenic, heavy metals like Cr, Cd, Pb, Co, and Ni pollution in agricultural soil and foods worldwide has increased in short order. Metals are indefatigable environmental pollutants that cause adverse effects on human health and the main entrance of those toxic metals in the human body through drinking or consuming contaminated foods and water. In this research, we have determined arsenic and other metals concentration in soil and food samples associated with health risk with possible multivariate statistical approaches like principal component and cluster analysis to identify the probable origin. The outcome of soil pollution measurement indices like contamination factor, geo-accumulation index, and enrichment factor revealed that the soil sample is strongly contaminated by arsenic, which is considered an anthropogenic activity. Two rice grains (R-1, R-3) and drumstick (Sajna) exceed the Indian standard of arsenic concentration (As- 1.1 mg/kg) in food. Compared with WHO, all the samples exceeded the WHO limit except Red amaranth in Cu and Pb, Guava in Cr, Cd, and Pb, and Drumsticks in Cu and Cd for food samples. Arsenic and Cd show the highest transfer factor in the soil to food sample. The high value of bioaccumulation index and translocation coefficient indicate that metals absorb in plant tissue both from soil and supplied contaminated water. In the case of daily ingestion of metals, all highly toxic metals like As, Ni, and Pb represent high concentrations and exceed the daily ingestion limit (As- 3µg kg-1day-1, Ni- 1.3µg kg-1day-1, and Pb- 3.57 µg kg-1day-1) developed by FAO/WHO and EFSA. From the potential hazard quotient, values of As and Pb indicate that residents are at high health risk. The results of carcinogenic risk for harmful metals indicate that for rice grain, the values of As, Pb, and Cd are greater than 10 − 6, which suggest that the inhabitant of the investigated area are at very high carcinogenic risk according to USEPA.

Although microplastic (MP) pollution of aquatic ecosystems is a high-priority study topic, the issue of terrestrial environment and textile manufacturing waste has received little attention. Thus, this study was carried out to investigate the presence of MPs in agricultural land near textile industries and textile sludge samples in Bangladesh. Thirty-two soil samples from four agricultural farmland and five sludge samples were collected and analyzed. We show that the MPs content from agricultural farmland soil and textile sludge samples was 2.13 × 10

The concentrations of eleven heavy metals (Pb, Cd, Cr, Fe, Mn, Zn, Cu, Ni, Co, As, and Ag) were assessed in both groundwater and seawater collected from the ship-breaking industrial area of Bangladesh using an atomic absorption spectrometer. The investigation aimed to estimate the water quality and pollution level employing several indices, and its associated health risks for the first time in that area. This study found that Cd, Cr, Fe, Pb, Mn, and Ni were higher in both groundwater and seawater compared with WHO standards. Based on the WQI (water quality index) and EWQI (entropy water quality index) classifications, the quality of most of the groundwater is extremely poor or unsuitable for drinking purposes. Furthermore, the HPI (heavy metal pollution index), HEI (heavy metal evaluation index), and CD (degree of contamination) values of most groundwater and all seawater samples exhibit a higher degree of pollution. In addition, the results of NI (Nemerow pollution index) come to an end that both groundwater and seawater in the study area are mostly polluted by Fe, Mn, Pb, Cr, and Cd. Although the HI (hazard quotient index) values of almost all studied heavy metals in both cases of adults and children are within the safe limit, the HI value of Cr for an adult is near the threshold limit and the maximum HI value of Cr for children exceeds this limit. The carcinogenic risk reveals that Cr, Pb, As, and Cd produce detrimental effects on local people through the direct ingestion of groundwater. The pollution source is identified using principal component analysis and a Pearson correlation matrix as being primarily anthropogenic and attributed to intensive ship-breaking activities or other industries in the area.

The study was performed to evaluate the abundance and characteristics of MPs in water, sediment, and fish samples of three major urban lakes, namely Dhanmondi Lake, Gulshan Lake, and Hatir Jheel Lake in Dhaka, Bangladesh. The abundance of microplastics varied from 0-9 items/L in surface water, 0-16 items/kg in sediment, and 0-17 items/individual; 0-4.88 items/g in the gastrointestinal tract (GIT) of test fish species, respectively. Highest abundance of microplastic in an individual fish was observed in Oreochromis mossambicus from Dhanmondi Lake. The samples were visually observed under a stereo microscope, which showed the dominant type of microplastics in both water and sediment samples were films followed by micro pellets, fragments, fibers, and in fish samples pellets and foams were dominant. According to the Fourier Transform Infrared analysis (FTIR) the dominant polymers in the analyzed samples were High density polyethylene (HDP), Ethylene Vinyl Acetate (EVA), Polyvinyl chloride (PVC), Polycarbonate (PC), Cellulose Acetate (CA), and Polypropylene (PP). In water and sediment samples of Gulshan Lake, MPs were relatively higher than in other lakes, and in fish samples of Dhanmondi Lake MPs were higher. The results of this study indicate that MPs were abundant in studied lakes and suggested a high level of microplastic contamination occurred not only in the water and sediment but also in the resident fishes. The implication of the finding suggests that the presence of MPs in urban lakes has raised concerns about the potential human health impact.

Indexical assessment coupled with a self-organizing map (SOM) and positive matrix factorization (PMF) modeling of toxic metal(loid)s in sediment and water of the aquatic environment provides valuable information from the environmental management perspective. However, in northwest Bangladesh, indexical and modeling assessments of toxic metal(loid)s in surface water and sediment are still rare. Toxic metal(loid)s were measured in sediment and surface water from an urban polluted river (Ichamati) in northwest Bangladesh using an atomic absorption spectrophotometer to assess distribution, pollution levels, sources, and potential environmental risks to the aquatic environment. The mean concentrations (mg/kg) of metal(loid)s in water are as follows: Fe (871) Mn (382) Cr (72.4) Zn (34.2) Co (20.8) Pb (17.6) Ni (16.7) Ag (14.9) As (9.0) Cu (5.63) Cd (2.65), while in sediment, the concentration follows the order, Fe (18,725) Mn (551) Zn (213) Cu (47.6) Cr (30.2) Ni (24.2) Pb (23.8) Co (9.61) As (8.23) Cd (0.80) Ag (0.60). All metal concentrations were within standard guideline values except for Cr and Pb for water and Cd, Zn, Cu, Pb, and As for sediment. The outcomes of eco-environmental indices, including contamination and enrichment factors and geo-accumulation index, differed spatially, indicating that most of the sediment sites were moderately to highly polluted by Cd, Zn, and As. Cd and Zn content can trigger ecological risks. The positive matrix factorization (PMF) model recognized three probable sources of sediment, i.e., natural source (49.39%), industrial pollution (19.72%), and agricultural source (30.92%), and three possible sources of water, i.e., geogenic source (45.41%), industrial pollution (22.88%), and industrial point source (31.72%), respectively. SOM analysis identified four spatial patterns, e.g., Fe-Mn-Ag, Cd-Cu, Cr-Pb-As-Ni, and Zn-Co in water and three patterns, e.g., Mn-Co-Ni-Cr, Cd-Cu-Pb-Zn, and As-Fe-Ag in sediment. The spatial distribution of entropy water quality index values shows that the southwestern area possesses "poor" quality water. Overall, the levels of metal(loid) pollution in the investigated river surpassed a critical threshold, which might have serious consequences for the river's aquatic biota and human health in the long run.

Microplastic pollution is a global concern, mainly due to its adverse effects on organisms and ecosystems. However, our knowledge of its impact on humans, in particular, is still very limited. Thus, while we have not gathered definitive information on their consequences, studies that aim to identify the MP's sources constitute subsidies to better understand the various exposure pathways to these pollutants. Thus, we investigated the possible presence of MP-like particles in teabag samples (of different brands) obtained in Dhaka, Bangladesh. Surprisingly, all analyzed samples (five brands) were contaminated with MPs. Fragments and fibers were identified in a higher percentage, and a wide variety of colors was identified, with a predominance of brown, blue, and red colors. Scanning electron microscope images of teabags exhibited net-like structures of fiber particles with a smooth surface. Furthermore, we observed irregularly shaped MPs and rougher surfaces and fragments in the process of detachment from the main fiber, oxidation flakes, and fracture-like. The average size of these pollutants was between 200.6 and 220.7 μm, and the polymer types identified via Fourier-transform infrared spectroscopy (FT-IR) were polytetrafluoroethylene, high-density polyethylene, polycarbonate, nylon, polyvinyl chloride, polytetrafluoroethylene, ethylene-vinyl acetate, cellulose acetate, and acrylonitrile butadiene styrene, the last three being the most frequent in the analyzed samples. Finally, we noticed that MPs from tea bags in Dhaka could cause an average emission of 10.9 million grams of MPs/year. Although the teabags analyzed in our study are not "complemented with the appealing flavor of MPs", it is very likely that tea ingestion in Dhaka is accompanied by the concomitant ingestion of plastic particles making teabags an important route of human exposure to these micropollutants.

This study was aimed to evaluate eggplant's growth-enhancing activity of chlorpyrifos and diazinon-degrading endophytic and rhizospheric soil bacteria isolated from cauliflower and tomato roots and the rhizospheric soil of rice roots, respectively. The identified endophytes belong to the Acinetobacter, Enterobacter and Klebsiella genera, while rhizospheric soil isolates belong to Pantoea, Acinetobacter, Kosakonia, Morganella, Enterobacter, and Klebsiella genera with species variation and genetic distances. All the strain's consumed 100% (50 mg/5 mL) chlorpyrifos and diazinon after 14 days of exposure, except for Pantoea sp. HSTU-Sny4 (84%) and Kosakonia sp. HSTU-ASn39 (42%). The strain's exhibited N-fixation, P-solubilization, indole-3-acetic acid (IAA), and ACC-deaminase production capabilities. The individual strain's and consortium treatment enhanced eggplant growth at germination, seedling, vegetative and reproductive stages. Plant growth-promoting genes, e.g., nif-cluster, chemotaxis, phosphates, sulfur, abiotic stress, chemotaxis, biofilm formation and organophosphorus insecticide-degrading genes were annotated in Klebsiella sp. HSTU-Sny5 and Morganella sp. HSTU-ASny43 genomes. Importantly, the mixed consortium supplemented with 40% urea-treated eggplants demonstrated similar growth parameters compared to the 100% urea eggplants. Plenty of insecticide-degrading proteins belonged to HSTU-Sny5 and HSTU-ASny43 strain's and had interacted with 100 different insecticides as confirmed in virtual screening. This research has a significant role in reducing the application of chemical fertilizer and bioremediation of pesticides in agriculture.

The endophytic bacterium Burkholderia contaminans NZ was isolated from jute, which is an important fiber-producing plant. This bacterium exhibits significant growth promotion activity in in vivo pot experiments, and like other plant growth-promoting (PGP) bacteria fixes nitrogen, produces indole acetic acid (IAA), siderophore, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. B. contaminans NZ is considered to exert a promising growth inhibitory effect on Macrophomina phaseolina, a phytopathogen responsible for infecting hundreds of crops worldwide. This study aimed to identify the possibility of B. contaminans NZ as a safe biocontrol agent and assess its effectiveness in suppressing phytopathogenic fungi, especially M. phaseolina. Co-culture of M. phaseolina with B. contaminans NZ on both solid and liquid media revealed appreciable growth suppression of M. phaseolina and its chromogenic aberration in liquid culture. Genome mining of B. contaminans NZ using NaPDoS and antiSMASH revealed gene clusters that displayed 100% similarity for cytotoxic and antifungal substances, such as pyrrolnitrin. GC-MS analysis of B. contaminans NZ culture extracts revealed various bioactive compounds, including catechol; 9,10-dihydro-12’-hydroxy-2’-methyl-5’-(phenylmethyl)- ergotaman 3’,6’,18-trione; 2,3-dihydro-3,5- dihydroxy-6-methyl-4H-pyran-4-one; 1-(1,6-Dioxooctadecyl)- pyrrolidine; 9-Octadecenamide; and 2- methoxy- phenol. These compounds reportedly exhibit tyrosinase inhibitory, antifungal, and antibiotic activities. Using a more targeted approach, an RP-HPLC purified fraction was analyzed by LC-MS, confirming the existence of pyrrolnitrin in the B. contaminans NZ extract. Secondary metabolites, such as catechol and ergotaman, have been predicted to inhibit melanin synthesis in M. phaseolina. Thus, B. contaminans NZ appears to inhibit phytopathogens by apparently impairing melanin synthesis and other potential biochemical pathways, exhibiting considerable fungistatic activity.

Substantial quantity of fish has been imported to Bangladesh without adequate food safety assessment which can pose a serious health risk to local people. This study analyzed the trace metals and organochlorine pesticides residues and the associated human health risk in 33 imported fishes (9 species) from four countries (India, Myanmar, Oman and United Arab Emirates) collected from three different ports (Benapole, Bhomra, and Chittagong) of Bangladesh with invoice lists from the port authorities. Trace metal concentrations were determined using graphite furnace absorption spectrometry and flame absorption spectrometry. The two organochlorine pesticides (Aldrin and Chlordane) residues were determined by GC-MS and found as below detection level (BDL). The trace metal concentrations (mg/kg-ww) in imported fish samples ranged as: As: 0.008 to 0.558; Pb: 0.004 to 0.070; Cr: 0.010 to 0.109; Cd: 0.00 to 0.083; Ni: 0.011 to 0.059; Co: BDL to 0.067; Mn: BDL to 0.0780; Fe: 1.780 to 10.77; Cu: 0.055 to 0.632; and Zn: 0.898 to 9.245. Concentrations of As and Cd were higher than the food safety guideline. Considering the source country of imported fishes, fish samples from Oman were mostly contaminated by the trace metals. The estimated daily intake (EDI) was higher for As and Cr. However, the target hazard quotient (THQ) for individual metal and total THQ for combined metals were lower than 1, indicating no apparent non-carcinogenic health risk for consumers. But target cancer risk (TR) was higher for As, and Ni and the values exceeded the acceptable range indicating a high carcinogenic risk for the local people. Therefore, extensive monitoring of these toxic chemicals is needed prior to import these fishes to the country. Given the self-sufficiency in fish production this study also argues whether Bangladesh needs to import the fishes at all.

In this study, banana stalk was used as a feedstock to produce hydrochar by hydrothermal carbonization (HTC). The effect of varying carbonization temperature (160 to 200 °C), varying reaction time (1 to 3 h) on yield, and higher heating value (HHV) of hydrochar was examined. With increasing temperature and reaction time, the hydrochar yield varied from 57.8 to 75.3%, whereas HHV varied from 18.1 to 18.9 MJ/kg. The carbon content, energy density, and energy recovery of all of the hydrochars were improved after conversion. The decrease of the O/C and H/C values was in agreement with the increasing coalification of hydrochars with increasing the severity of HTC conditions. The surface characteristics and thermal degradation properties of hydrochars were also assessed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The low ash and sulfur content after the HTC process indicates that banana stalk hydrochar can be a potential raw material for energy production.

Aim: The current study explores the proximate and elemental contents of three different medicinal plants, namely Cuscuta reflexa (whole plant), Cassia tora (stem) and Cassia fistula (seed pot) that have been grown in Bangladesh. Methodology: Macro (Na, K, Ca, Mg), micro (Fe, Cu, Mn, Zn, Ni, Cr) and heavy metal (Pb, Cd, As) elements, present in C. reflexa (Whole plant), C. tora (stem), and C. fistula (seed pod) were analyzed quantitatively by flame photometer and atomic absorption spectroscopy (AAS). Results: The minerals of the plants were found in substantial amounts (Na: 13763.75-16419.42 ppm, K: 6053.49-25864.92 ppm, Ca: 18912.16-2298.77 ppm, Mg: 1570.25-4602.23 ppm, Fe: 58.99-222.43 ppm, Cu: 3.16-11.61 ppm, Mn: 15.89-54.53 pm, Zn: 0.0367-50.2665 ppm, Ni: 0.9878-4.7186 ppm, Cr: 0.3279-0.8281 ppm, Pb: 0.3590-1.5030 ppm, Cd: 0.0016-0.0068 ppm and As: 0.0148-0.0675 ppm). Conclusion: It is evident that the investigated medicinal plants are enriched in some macro and micro nutrient, such as Na, K, Ca, Mg, Fe etc which are important for biological metabolism and human health. On the other hand the heavy metals are present in trace amount which indicate the plants are safe for medicinal uses.

To understand the mechanistic pathway of arsenic (As) enrichment and mobilization in groundwater (southeastern Bangladesh) and to evaluate the water quality as well as associated health risks, a suite of systematically collected groundwater samples (depth: 17-61 m) were analyzed. Arsenic concentrations (μg L

Tannery wastewater is a significant cause of chromium (Cr) contamination in land and water. This study assessed Cr contamination caused by the discharge of tannery wastewater in the Dhaleshwari River and identified possible native plants for phytoremediation of Cr. Water, soil and sediments samples were collected from upstream and downstream of the wastewater discharge channel of Savar tannery industrial estate situated on the bank of the river. Samples of root, stem, leaf and fruit of four selected plants (i.e., Eichhornia crassipes, Xanthium strumarium L., Cynodon dactylon, Croton bonplandianum Baill.) were also collected from those sampling points. The total Cr in acid digested samples were determined by flame atomic absorption spectrometry. High concentrations of Cr were detected in the water, soil and sediment samples collected near the wastewater discharge channel. Of all the plant species, Xanthium strumarium L. exhibited high translocation factors (TF) and bioconcentration factors (BCF) for Cr. Based on the findings of this study Xanthium strumarium L. is preferable as a native species for phytoremediation of Cr.

Heavy metal pollution in agricultural soils and food crops around the ship breaking area is of great environmental and human health concern. In this work, we have spectroscopically determined the concentrations of Cd, Pb, Fe, Mn, Zn, Cr, Cu, and Ni in agricultural soils and commonly consumed vegetables, fruits, and rice grain collected from the Sitakunda ship breaking area of Chittagong, Bangladesh, in order to evaluate their contamination levels and probable human health risk with a multivariate statistical approach. Multivariate analyses such as principal component analysis and cluster analysis of the analytical data indicate a significant metal contamination in the samples which could be attributed to industrial activities such as ship breaking. The results of soil contamination evaluation indices such as enrichment factor, geo-accumulation index, and contamination factor demonstrated that the soils around the ship breaking area are mainly contaminated by Cd, Pb, Zn, and Cu while food crops were mostly contaminated by Zn, Cr, and Cu. The Pb contaminated the olive and teasle gourd while Cd contamination in rice grain was at the threshold limit for health hazard. Mn was slightly accumulated in banana. Transfer coefficient values of Cd, Zn, and Cu for almost all food crops were higher than other metals, and Cd showed the highest transfer. Estimated daily intake values for Ni exceeded the standard limit (1.3 μg kg−1 day−1). Target hazard quotient values of Cu, Zn, Pb, and Cd indicate that the local inhabitants who consume the contaminated food crops are being exposed to potential health risks.

The present study was conducted for the first time to appraise the water quality, irrigation feasibility, and human health risk of surface water in heavy industrial and urban establishments from a coastal city of Bangladesh. Surface water samples were collected from the hilly terrain comprised of Plio-Pleistocene to Miocene-sediments throughout the study area. The ranges of pH were 5.35 to 7.58, EC values were 42.3 to 2440 µS cm−1, and turbidity were 2.53 to 1570 NTU, respectively. The overall physicochemical condition of water samples revealed that the water was unsuitable and also unsafe for domestic use. A bias-free systematic sampling and analyzed parameters invoke that surface water quality is deteriorated by Cr (52.2), Mn (532), Fe (4797), Mg (31445), K (29213), Co (69.0), Ni (39.5), and Pb (22.4 µg L−1) contamination and make the surface water unsuitable for drinking, cooking, fisheries, and other purposes. Anthropogenic activities (e.g., domestic, industrial, agricultural, etc.) intensified by climate change-induced sea-level rise are mainly responsible for the source apportionment of metal pollution in the study region. However, the surface waters of the studied sites are allowed to use for irrigations, except for Karnaphuli river due to high alkali hazards. Furthermore, the existence of toxic metal-induced non-carcinogenic and carcinogenic risks does not allow inhabitants to use this water for household works.

Overexploitation of groundwater, sea level rising, shrimp cultivation, etc. are the main causes of seawater intrusion in the coastal aquifers which is a growing concern around the globe. So to evaluate the seawater intrusion in the coastal aquifers of southern Bangladesh (Paikgachha, Khulna), water quality parameters such as pH (7.75–8.82), EC (371–5320 µS cm−1), TDS (182–2790 mg L-1), salinity (0.1–2.8 ppt), Na+ (14.8–1376 mg L-1), K+ (2.71–19.4 mg L-1), Ca2+ (33.2–192 mg L-1), Mg2+ (25–138 mg L-1), Cl- (18.2–3168 mg L-1), HCO3− (205–840 mg L-1), and CO32− (6.22–149 mg L-1) for 20 composite water samples, along with the hydro-geo-physical entities were utilized. Additionally, groundwater quality distributions were also appraised for identifying the suitable water sources for drinking and irrigation. Most of the sampling sites possessed mainly NaCl-type groundwater where Na+ and Cl- contents were 2–6 times higher than the recommended limits. Indices-based calculations indicated that only 35% of the sampling sites can provide good quality drinking water whereas groundwaters from >50% of sampling sites were unsuitable for irrigation. Statistical approaches reveal the potential seawater intrusion with trivial evidence of carbonate mineralization. Distributions of seawater intrusion vulnerability among the studied area were specified by the GALDIT index. The central (30%), southern (25%), and northern (45%) parts were identified as high, moderate, and low vulnerable zones, respectively due to saline water. Thus, considering the heterogenic distribution of seawater intrusion vulnerability among the studied unconfined aquifers, more intimate and detailed groundwater investigations are required on a periodical basis to explore water for drinking and irrigation.

Dhaka was established as a provincial capital of the Mughal ruler on the north-eastern bank of the Buriganga River during 1608-10. This river has enormous significance to the residents of Dhaka. Not only it surrounds the city, but also it provides important services to the residents including water supply, navigation, recreation, sanitation, fish production, tourism, biodiversity and flood control. A study was carried out to observe the ecological health hazards and their risk to human health of the Buriganga River. The samples were analyzed to determine water quality. The study showed that the water is high in biological oxygen demand (BOD), chemical oxygen demand (COD), Electrical conductivity (EC), Total dissolved solid (TDS), Salinity, Alkalinity, Turbidity and low in dissolved oxygen (DO) which revealed huge environmental health risks and possible ecological disruption of this river.J. Environ. Sci. & Natural Resources, 10(1): 75-80 2017

Arsenic (As) concentration and geochemical analysis of groundwater as well as core sediments of 20 tube wells revealed the uppermost aquifer (20–40 m of depth) groundwater As concentrations ranging from 2.34 to 586.96 μg L−1, and groundwater geochemical conditions change from oxidized to gradually more reduced as higher concentrations of As increased with depth. The highest sediment As levels (25 mg kg−1) were found within the shallow depth (15 m). The groundwater of the study area is of Ca-HCO3 type, where Ca is the dominant metal with high concentrations of As, Fe, and Mn but low levels of NO3− and SO42−. The trace elements Fe, Mn, and As exceed the WHO and DoE standard in groundwater which clearly indicated As contamination except some few areas where less Fe and Mn are released in aquifer water from sediment. The contaminated As zone also corroborated with the GIS study. Considerable variability with depth and location is noted in the levels of As, Fe, and Mn in groundwater, and from these levels it can be seen that the groundwater of Rajarampur village of Chapai Nawabganj Paurasava is more reduced than the groundwater of Baragharia. Groundwater in Baragharia village contains low concentration of As below the WHO standard (

In this work, fifteen chemical elements viz., Pb, Cd, Cr, As, Ag, Mn, Fe, Co, Ni, Cu, Zn, Na, K, Ca, and Mg were estimated in the coal mine-impacted soil samples sourced from Barapukuria coal mine area of Bangladesh using atomic absorption spectrometer and flame photometer for assessing their contamination levels with an implication to human health and environment. The level of considered elements was found to be lower compared to their corresponding world normal limit, except for Zn. Physicochemical properties of soils such as pH, oxidation-reduction potential, and electrical conductivity, as measured using a multiparameter meter in aqueous solution, indicated the acidic nature of soils with the presence of considerable oxidizing and ionic substances. Principal component, cluster, and correlation analyses ascertained the probabilistic anthropogenic sources of elemental contaminations and significant inter-parameter associations. These analyses suggest that Zn, Cu, Ni, Co, Cd, Mn, and As in soil originated from anthropogenic activities, particularly from the adjacent coal mining operations, indicating a common source of origin. Enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), ecological risk factor (Er), potential ecological risk index (RI), and human health risk assessment of chemical elements were employed for evaluating the impact of potentially hazardous elements in soils on surrounding environment and local residents. EF values suggest a significant enrichment of Ag, As, Zn, Cd, Pb, Co, Ni, Mn, and Cu in soils having anthropogenic origin while K, Cr, Ca, Na, and Mg originated from geogenic sources. The Igeo and CF data indicate a considerable accumulation of Cd, As, Ag, and Zn in the soil. A moderate risk potential was manifested by the Er and RI indices posing a threat to the soil environment. The non-carcinogenic threat was observed mostly among the children cohort due to the preponderance of these elemental concentrations.

This research paper provides the formulation idea of herbal ultrasound gel that is of good quality. In this formulation some available chemicals and natural ingredient were used which has no harmful effect to human skin. Chemicals that used were poly acrylic acid, sodium benzoate, glycerine, food grade color, tri-ethanolamine and natural ingredient is aloe vera extract which shows effective activity against allergic, irritation and inflammation problem due to its synergistic property. Firstly, aloe gel was extracted by ethanol extraction. Gel was formulated combining all ingredients. To justify the effectiveness of any formulation, results of evaluation tests are very important. For this, necessary physicochemical properties such as appearance, transparency, consistency, homogeneity, pH, thermal stability, conductivity, spreadability, viscosity etc. were evaluated. The results were satisfactory. No microbial growth was found during the incubation period for the prepared ultrasound gel. Also, no adverse effect to the human skin like irritation, allergy, inflammation etc. was observed. Ultrasound gel usually acts as a conductive medium and the conductivity result provides the information about the image quality. Conductivity of this formulated gel was 4.05 µS/cm. Using this formulated ultrasound gel during ultrasonography, clear image was found which was also of good quality. The overall results suggest that this formulation can be considered as successful and used with no harmful effect compared to the synthetic ones.

The study was conducted to analyze the chemical parameters and major anionic contents of water from Taltola and Mullahbari Pond at Santosh, Tangail during the months from January to March 2014. Chemical parameters such as pH, EC, DO, TDS, BOD and Alkalinity of all water samples were ranged from 7.56 to 7.78, 239.7 to 342 μS/cm, 4.3 to 5.7 mg/L, 123.7 to 175 mg/L, 2.1 to 2.63 mg/L and 87 to 154 ppm, respectively. On the other hand, the anions such as F - , Cl - , NO 2 - , NO 3 - , SO 4 -- were ranged from 0.221 to 3.8, 16 to 24, 2.5 to 3.8, 0.96 to 1.67 and 1.99 to 17.93 mg/L, respectively. In case of Br - the anionic value of water sample was not detectable. DOI: http://dx.doi.org/10.3329/jesnr.v7i2.22213 J. Environ. Sci. & Natural Resources, 7(2): 89-92 2014

This paper describes the preparation and characterization of mixed ligand complexes of Co(II) and Fe(III) ions with malic acid and heterocyclic amines. The general formula of the complexes are as follows: [M(MA)L2] and K[M(MA)2L2] (where, M = Co(II) (1-4), Fe(II) (5-8); MA = C4H4O5 (1-4), 2C4H4O5 (5-8); L = C6H5N (1), C6H7N (2), C9H7N (3, 4), 2C6H5N (5), 2C6H7N (6), 2C9H7N (7-8). The complexes were prepared in the solid form and characterized by elemental analysis, conductivity and magnetic measurements, infrared and electronic spectroscopic studies. The infrared spectra of the complexes confirmed the coordination of metal ion with ligands. The Co(II) complexes are assumed to have tetrahedral and the Fe(III) complexes have octahedral structure based on the electronic spectra and magnetic measurements. Their antibacterial and antifungal activity has also been evaluated by the disc diffusion methods against fourteen pathogenic bacteria (five gram positive and nine gram negative) and fourteen fungi. Complexes [Co(II)(MA)(4-pico)2] showed the highest antibacterial activity against all bacteria tested (when, MA= C4H4O5 and 4-pico = C6H7N). DOI: http://dx.doi.org/10.3329/bpj.v15i2.12589 Bangladesh Pharmaceutical Journal 15(2): 177-181, 2012

In addition to arsenic, the groundwater in Bangladesh is often found to be contaminated with manganese whose permissible limit set by WHO being 400 ppb in drinking water. Since most arsenic removal technologies (ARTs) are designed to remove As and not to remove Mn, during field testing and verification of performance of ARTs under the Bangladesh Environmental Technology Verification-Support to Arsenic Mitigation (BETV-SAM) project of BCSIR, it has been found that only the Sono technology using Fe0 as arsenic removal medium which can also remove Mn to produce Mn safe drinking water but others such as Alcan, Read-F household, Sidko, Nelima, Shawdesh cannot. During field testing of these technologies under the BETV-SAM project, it has been attempted to treat Mn by a traditional chlorine oxidation method to produce Mn safe drinking water. Concentrations of dissolved As (T), As (III), Fe, Mn and pH in the considered well water for manganese treatment were in ranges of 125 - 1247 ppb, 116 - 1127 ppb, 1.40 - 15.5 ppm, 505 - 2245 ppb and 7.0 to 7.5, respectively. The required chlorine dose and time for treatment of manganese in 20 L water have been found to be 6.2 - 12.4 ppm and 1 - 2 h, respectively. Keyword: Arsenic; Manganese; ART; Verification; Chlorine; Iron. DOI: http://dx.doi.org/10.3329/bjsir.v46i3.9033 BJSIR 2011; 46(3): 291-296

The Bangladesh Environmental Technology Verification - Support to Arsenic Mitigation (BETV-SAM) program objectively assessed thirteen arsenic removal technologies (ARTs) that had been submitted for performance verification, and selected seven technologies for the field testing and performance verification. Each technology was deployed to five hydrogeologically distinct regions of Bangladesh and was tested on five wells (with replicate units installed and tested on two wells). Raw and treated water samples were collected at regular intervals and were analysed for arsenic and other water quality parameters. The data were analysed using standard statistical software and the performance of individual ARTs have been evaluated and compared with the proponent's claim. Two technologies (STAR & CIWP) performed well while five other technologies performed poorly and their claims were rejected. The results of the first-round of the BETV-SAM field testing and performance verification program presented and discussed in this paper, may be important from a technological design and development point of view. Key words: Arsenic removal technology; Field testing; Performance verification; Water quality parameters. DOI: 10.3329/bjsir.v45i4.7325 Bangladesh J. Sci. Ind. Res. 45(4), 289-302, 2010