Organophosphorus insecticides mineralizing endophytic and rhizospheric soil bacterial consortium influence eggplant growth-promotion.

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.

Chromium Contamination from Tanning Industries and Phytoremediation Potential of Native Plants: A Study of Savar Tannery Industrial Estate in Dhaka, Bangladesh.

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.

Chemical and physicochemical characterization of effluents from the tanning and textile industries in Bangladesh with multivariate statistical approach.

Industrial effluents are one of the foremost concerns relating to the anthropogenic environmental pollution. The effluents from the tanning and textile industries in Dhaka, Bangladesh, were characterized chemically and physicochemically with multivariate statistical techniques. The concentrations of heavy metals viz., Pb, Cd, Cr, Mn, Fe, Ni, Cu, and Zn were determined by atomic absorption spectrometer while concentrations of anions viz., F-, Cl-, NO2-, NO3-, and SO42- were measured by ion chromatograph. The physicochemical parameters viz., temperature, pH, electrical conductivity (EC), salinity, turbidity, dissolved oxygen (DO), and biological oxygen demand (BOD) were measured by a multiparameter meter while total suspended solids (TSS) and total dissolved solids (TDS) were measured gravimetrically. This study showed that effluents from both industries demonstrated high levels of TSS, TDS, EC, and heavy metals. Tannery effluents have lower pH and DO, and higher BOD, Cl-, SO42-, and Cr concentrations while textile dyeing effluents have higher pH, NO2-, and NO3- concentrations, compared to the standard limits promulgated by the Bangladesh government. Multivariate statistical techniques such as cluster analysis and principal component analysis along with the correlation matrices showed significant association among the measured parameters and identified pollution sources as well as effluent types in the study area which could be linked to the processes used in textile dying and tanning industries. This study will be useful for identifying pollutants emanating from the two industries and will guide future industrial aquatic studies where multiple industrial runoffs are concerned.

Techniques for quantification of organochlorine pesticides from a validated method by using gas chromatography-electron capture detector.

Organochlorine pesticides (OCPs) are persistent organic compounds found in aquatic environments worldwide. A well-validated and well-established analytical method is crucial for detecting OCPs in the environment. In this study, an analytical method for quantifying OCPs in water was developed and evaluated. Here, the range of linearity, reproducibility, uncertainty, specificity, method detection limits (MDL), and special emphasis on detection and quantitation limits were assessed. Recovery studies were performed to measure the accuracy and precision of the method. This method exhibited excellent linearity in the range of 2.5-20 µg/L for all compounds. As none of the targeted compounds was detected in the chromatograms of the blank sample with no baseline noise, the limits of detection (LOD) and limits of quantification (LOQ) were determined using the linear regression method, external calibration curve slope, and laboratory fortified blank-based detection. All compounds showed different LOD and LOQ values, depending on the approach used. In particular, endosulfan sulfate, methoxychlor, endrin ketone, H. epoxide, heptachlor, and 4,4'-DDT exhibited high detection limits. The recovery percentage of the 15 compounds at 5 µg/L spiked concentration was between 50 and 150 %, which is consistent with the accuracy of the APHA method. Except for endosulfan sulfate, the relative standard deviations of all other compounds were below 20 %, indicating good precision. This method has also been applied to real water samples. This validation technique is reliable, sensitive, simple, rapid, easy to comprehend, and reproducible. The application of this method in the real water samples was also conducted. Only α-BHC and γ-Chlordane were detected in the water sample.

An industrially potent rhamnolipid-like biosurfactant produced from a novel oil-degrading bacterium, Bacillus velezensis S2.

Surfactants can reduce the interfacial surface tension between two immiscible liquids making them a desirable component for various industrial applications. However, the toxic nature of chemical surfactants brought immense attention towards biosurfactants. Being biodegradable, biosurfactants are eco-friendly and considered safer for different commercial uses. This study focused on the production of biosurfactant from an oil-degrading bacteria and its functional efficacy for prospective industrial applications. Here, a promising oil-tolerant strain, Bacillus velezensis S2 was isolated from oil contaminated sites which showed >50% degradation of convoluted crude oil within 28 days in comparison to a control. The isolate was then found to produce an excellent surface-active compound with an emulsification index of 67.30 ± 0.8% and could reduce the surface tension up to 36.86 ± 0.36 mN m-1. It also manifested a critical micelle concentration of 45 mg L-1 while reducing the surface tension from 72 to 30 mN m-1. When extracting biosurfactant from isolated bacteria, ethyl acetate extraction showed 1.5 times greater efficacy than chloroform : methanol extraction. The purified biosurfactant was characterized using TLC, 1H NMR, 13C NMR, FTIR, elemental analyses and spectrophotometric techniques leading to its identification as a rhamnolipid. The stability of produced biosurfactant at higher temperature (up to 180 °C) was determined by thermal analysis, endorsing its application in high temperature reservoir conditions. Additionally, the extracted biosurfactant showed excellent foaming efficacy with insignificant antibacterial and cytotoxic responses, which indicates their potential application in cleaning and cosmetics industries. Thus, the present study outlines a bi-functional novel isolate Bacillus velezensis S2 which could play a significant role in oil remediation from the environment as well as serve as a potential source of non-toxic and eco-friendly biosurfactants for various industrial applications.

Origin, spatial distribution, sediment contamination, ecological and health risk evaluation of trace metals in sediments of ship breaking area of Bangladesh.

Eleven trace metals (Cd, Cr, Fe, Mn, Cu, Ni, Co, Zn, As, Pb, and Ag) in sediments of Bangladesh's ship breaking area were measured by an atomic absorption spectrometer to determine origin, contamination extent, spatial distributions, and associated ecological and human health hazards. This study found considerable quantities of Pb, Cd, Mn, Zn, and Cu when compared with standards and high levels of Pb, Cd, Zn, Cu, As, and Ag contamination according to pollution evaluation indices. Different indices indicate most of the sampling sites were highly polluted. However, spatial distribution maps indicate that trace metals were predominantly deposited in the northern and southern region. The ecological risk index revealed that Cd has the highest while Pb and As had moderate risk. Based on the health index values, Zn for both adults and children were higher than the safe limit while Mn, Pb, Cr, As, Fe, Cu, Ni, and Co for children were close to the threshold. The mean total carcinogenic risk values of Cr, As, and Ni for children and Ni for adults exceeded the permissible threshold. The cancer risk possibilities were further assessed using Monte Carlo simulation. Most trace metals have anthropogenic origins, which were attributed to ship breaking activities.

Comprehensive analysis of phytochemical profiling, cytotoxic and antioxidant potentials, and identification of bioactive constituents in methanoic extracts of Sonneratia apetala fruit.

In the delta region of Bangladesh, Sonneratia apetala, also known as Keora and mangrove apple, is widely recognized for its dual role as a source of both food and medicine. Seasonal S. apetala fruits were gathered from Hatiya, Noakhali, in October 2021. The samples were segregated into pericarps and seeds, then fractionated into methanol segments. The anti-proliferative activities of these samples against lung A549 cells were evaluated using the Trypan blue exclusion method. Additionally, High-Performance Liquid Chromatography (HPLC) was employed to quantify phenolic compounds, while standard protocols facilitated the identification of specific phytochemical constituents. Chemical profiling via Gas Chromatography-Mass Spectrometry (GC-MS) and the isolation and detection of bioactive compounds through column chromatography and Nuclear Magnetic Resonance (NMR) analysis were undertaken. The methanol fractions of the seeds and pericarp were found to contain carbohydrates, tannins, flavonoids, steroids, alkaloids, glycosides, and terpenoids, with the absence of saponins and anthraquinones. Notably, the anti-proliferative effect demonstrated statistical significance at a concentration of 300 µg/mL for both extracts. Furthermore, HPLC analysis identified and quantified six polyphenols: catechin hydrate, (-)-epicatechin, rutin hydrate, trans-ferulic acid, trans-cinnamic acid, myricetin, and kaempferol, with the following concentrations: 46.65 and 12.72; 349.29 and 140.39; 5.26 and 33.06; 10.35 and 29.28; ND and 11.93; and 10.03 and 7.90 mg/100 g in the methanol fraction of the seed and pericarp, respectively. GC-MS analysis of S. apetala fruit revealed five notable compounds with significant peak areas (%): 2-methyltetracosane, tetratetracontane, heptacosane, 1-chloro-2-hexyl-1-octanol, and phenol, 3,5-bis(1,1-dimethylethyl), exhibiting peak areas of 43.96, 35.8, and 15.95, respectively. Meanwhile, the notable peak in S. apetala seeds was 1,3-benzenedicarboxylic acid, bis(2-ethylhexyl) ester, with a peak area (%) of 100. These compounds are known for their anticancer and antioxidant properties. Therefore, S. apetala, particularly its seeds and fruits, shows promising potential for development into dietary supplements and functional foods.

Spatial distribution and hydrogeochemical evaluations of groundwater and its suitability for drinking and irrigation purposes in kaligonj upazila of satkhira district of Bangladesh.

Groundwater is a significant water resource for drinking and irrigation in Satkhira district, Bangladesh. The depletion of groundwater resources and deterioration in its quality are the results of the confluence of factors such as industrialization, intensive irrigation, and rapid population growth. For this reason, this study focused on the evaluation of tubewell water of six unions of Kaligonj upazila in Satkhira district, which is situated in the coastal southwest part of Bangladesh. Major and trace elemental concentrations were assimilated into positive matrix factorization (PMF) to identify potential sources and their respective contributions. Principal component analysis (PCA) revealed that groundwater salinization and manmade activities were the primary causes of heavy metals in the coastal groundwater. Its average pH value was found to be 7.5, while Dissolved oxygen, Total dissolved solids, salinity, and conductivity, with values ranging from 1.18 to 7.38 mg/L, 0.5-4.88 g/L, 0.4-5%, and 0.95 to 8.56 mS/cm, respectively. The total hardness average value was 561.7 mg/L, classified into the very hard water categories, which is why 90% of the tubewell water samples were unfit for household purposes. All samples had an excessive level of arsenic present. The iron concentration of fifteen (15) samples crossed the standard limit according to WHO 2011 value. Around 63% of the samples were of the Na+-K+-Cl--SO42- type, and about 72% were sodium-potassium and alkali types. 98% of samples were covered in chloride and bicarbonate. The findings showed that 45.83% of the groundwater samples had negative Chloroalkaline index (CAIs), while 54.16% had positive. The permeability index (PI) was an average of 73%, and residual sodium carbonate (RSC) averaged 260.2 mg/L, and the findings clearly showed that 80% of the samples weren't appropriate for irrigation. According to the sodium adsorption ratio (SAR) value, 65% of the samples fell into the unsuitable category. These calculations indicated a high overall salinity hazard in the study area, which may be caused by the intrusion of sea water given that the study area is close to the coastal region. Findings compared to standards revealed that the majority of the samples were deemed unfit for drinking and irrigation purposes. Hence, additional attention must be paid to this area to ensure the availability of drinkable water and to preserve sustainable farming practices.

Assessment of coastal river water quality in Bangladesh: Implications for drinking and irrigation purposes.

Saltwater intrusion in the coastal areas of Bangladesh is a prevalent phenomenon. However, it is not conducive to activities such as irrigation, navigation, fish spawning and shelter, and industrial usage. The present study analyzed 45 water samples collected from 15 locations in coastal areas during three seasons: monsoon, pre-monsoon, and post-monsoon. The aim was to comprehend the seasonal variation in physicochemical parameters, including water temperature, pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), hardness, and concentrations of Na+, K+, Mg2+, Ca2+, Fe2+, HCO3-, PO43-, SO42-, and Cl-. Additionally, parameters essential for agriculture, such as soluble sodium percentage (SSP), sodium absorption ratio (SAR), magnesium absorption ratio (MAR), residual sodium carbonate (RSC), Kelly's ratio (KR), and permeability index (PI), were examined. Their respective values were found to be 63%, 16.83 mg/L, 34.92 mg/L, 145.44 mg/L, 1.28 mg/L, and 89.29%. The integrated water quality index was determined using entropy theory and principal component analysis (PCA). The resulting entropy water quality index (EWQI) and SAR of 49.56% and 63%, respectively, indicated that the samples are suitable for drinking but unsuitable for irrigation. These findings can assist policymakers in implementing the Bangladesh Deltaplan-2100, focusing on sustainable land management, fish cultivation, agricultural production, environmental preservation, water resource management, and environmental protection in the deltaic areas of Bangladesh. This research contributes to a deeper understanding of seasonal variations in the hydrochemistry and water quality of coastal rivers, aiding in the comprehension of salinity intrusion origins, mechanisms, and causes.

Abundance and characteristics of microplastics in major urban lakes of Dhaka, Bangladesh.

Microplastics (MPs) are prevalent in nature due to the proliferation of plastic in the environment. However, the presence of microplastics in lakes is largely unknown in comparison to other aquatic bodies. This study was performed to evaluate the abundance and characteristics of MPs in water, sediment, and fish from three major urban lakes in Dhaka, Bangladesh, namely Dhanmondi, Gulshan, and Hatir Jheel lake. The highest concentrations of microplastics in surface water (36 items/L), sediment (67 items/kg), fish (17 items/individual), and the gastrointestinal tract (4.88 items/gm) were observed. Highest abundance of microplastic in an individual fish was observed in Oreochromis mossambicus from Dhanmondi Lake. The samples were visually examined using stereomicroscope and SEM, which revealed that films were the most prevalent kind of microplastics in both the water and the sediment samples, whereas pellets and foams predominated in the fish samples. Visual observation also revealed MPs dominated by <100 µm in size and transparent in color. According to the Fourier Transform Infrared (FTIR) analysis, the dominant polymers in the analyzed samples were high-density polyethylene, low-density polyethylene, ethylene vinyl acetate, polyvinyl chloride, polycarbonate, cellulose acetate, and polypropylene. MPs were relatively higher in the water and sediment samples of Gulshan Lake, and fish samples of Dhanmondi Lake. The results of this study indicate that microplastic contamination has occurred not only in the water and sediment but also in the inhabitant fishes of the lakes. However, it is discovered that the microplastic intake of fish was significantly related to body weight and length. The implication of the finding suggests that the presence of MPs in urban lakes has raised concerns about the potential human health impact.

Dissemination and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in water and sediment of Buriganga and Dhaleswari rivers of Dhaka, Bangladesh.

Concentration, source, ecological and health risks of sixteen polycyclic aromatic hydrocarbons (PAHs) were estimated for water and sediment samples of two urban rivers namely Buriganga River (BR) and Dhaleswari River (DR). The mean concentration of ∑PAHs in BR water and sediment were 9619.2 ngL-1 and 351.6 ngg-1, respectively. Furthermore, the average PAH concentrations detected in DR water and sediment were 1979.1 ngL-1 and 792.9 ngg-1, respectively. The composition profile showed that 3-ring PAHs were dominant in the water matrix; however, 5-ring PAHs were prevalent in the sediment samples of both rivers. Sources apportion study of PAHs indicated that mixed combustion and petroleum sources are responsible for PAHs contamination in the rivers. Ecological risk study of water suggested that the aquatic lives of both rivers are threatened by Fla, BbF, BkF, DahA, and IcdP, as presented above the threshold level. Comparison with sediment quality guidelines (SQGs) indicated that adverse effects might cause occasionally in the sediment ecosystem in DR at certain sampling sites for Nap, Acy, Fl, Phe, Ant, Pyr, Chr, BaP, and DahA. On the other hand, the presence of Nap, Acy and DahA might occasionally cause adverse biological effects in the BR sediment ecosystem. Estimated hazard quotient (HI > 1) and carcinogenic risk (CRtotal > 10-4) values indicated that local inhabitants living in the vicinity of the rivers are prone to high health risks.

Waste newspaper driven activated carbon to remove polycyclic aromatic hydrocarbon from wastewater.

In this study, a carbon-based adsorbent was developed from waste newspaper through pyrolysis at 800 °C to evaluate the removal efficiency of polycyclic aromatic hydrocarbons (Benzo[ghi]perylene (BghiP) and Indeno [1,2,3-cd] pyrene (IP)) from wastewater. The surface area of the developed adsorbent was estimated at 509.247m2g-1 which allowed the adsorption of the PAHs from wastewater. The maximum adsorption capacity was estimated at 138.436 µg g-1 and 228.705 µg g-1 for BghiP and IP, respectively and the highest removal efficiency was observed at pH 2. Around 91% removal efficiency was observed at pH 7 for both pollutants. Experimental adsorption data were fit for pseudo-second-order kinetics and Langmuir isotherm models, which demonstrate electrostatic interaction, monolayered deposition, hydrogen bonding, and π-π interaction between adsorbate and adsorbent which play a significant role in adsorption. The regeneration study described that the developed adsorbent could be able to intake 52.75% BghiP and 48.073% IP until the 8th and 6th cycles, respectively. The removal efficiency of the adsorbent in the real sample was also evaluated. This study will provide a method to convert waste material into adsorbent and will remove PAHs from wastewater as a function of pollutant mitigation and waste management.

Identification and quantification of microplastics in agricultural farmland soil and textile sludge in Bangladesh.

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 × 104 ± 0.13 × 104 MPs/kg and 2.92 × 104 ± 0.14 × 104 MPs/kg, respectively. MPs with a size between 1.0 and 1.5 mm were the least frequent in both soil and textile sludge samples. Fibers were more prevalent in textile sludge and fragments in soil samples. In addition, the percentage of transparent/white MPs was higher in the soil samples, and those classified as "multicolor" and "others" were more frequent in the sludge samples. Nine types of polymers were identified in the soil samples: PS, EVA, latex, HDPE, PVC, ABS, CA, LDPE, and PP. Except for LDPE, all these polymers were also found in the textile sludge samples, in addition to PU, nylon, and FEP, totaling eleven polymer types. On the other hand, we did not find evidence to support the association between MP contamination in soil samples and MPs identified in textile sludge samples. As demonstrated in the principal components analysis (PCA), the analyzed samples were separated by PC1, which suggests that the MPs reported in the soil come from sources that are not directly related to the textile industries. Thus, further research is needed to fully reveal MPs' fate and ecological risks in the soil environment and textile sludge, and necessary action is required to control MP pollution in terrestrial ecosystems.

Microplastics in different fish and shellfish species in the mangrove estuary of Bangladesh and evaluation of human exposure.

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.

Assessment of microplastics pollution in aquatic species (fish, crab, and snail), water, and sediment from the Buriganga River, Bangladesh: An ecological risk appraisals.

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 Cr > Pb > As>Cd. 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.

Exposure and health risks of metals in imported and local brands' lipsticks and eye pencils from Bangladesh.

Elemental contamination in cosmetics is a serious health concern as it can pose a cumulative effect on the user's body over a long period. The prime motive of the study was to assess the concentration of 10 concerning chemical elements (Pb, Cd, Cr, As, Co, Ni, Cu, Zn, Fe, and Mn) in imported and local lipsticks and eye pencil samples collected from retail outlets in central Bangladesh (Dhaka city) and to assess their dynamic health risks for users. A total of 18 lipsticks and 24 eye pencils were studied and concentrations of chemical elements were examined with atomic absorption spectrophotometer. The health risk assessment was performed for dermal and ingestion routes of the contaminants. The results reveal that the concentrations of the examined elements vary with colors, brands, and origins. Pb and As concentrations were found below the permissible limit but Cr concentration in some samples exceeded the allowable limit in cosmetics. Cd was not detected in any samples; however, other examined elements such as Co, Ni, Cu, Mn, Zn, and Fe were detected in considerable concentrations. Elements like Mn, Zn, and Fe were found at high levels. In the case of lipstick samples, elemental concentrations followed the order of Fe > Zn > Mn > Ni > Cr > Cu > Pb > Co > As, while the order was Fe > Cu > Mn > Zn > Ni > Cr > Co > Pb > As for eye pencil samples. Results of the hazards quotient (HQ) indicate that there were no non-carcinogenic or carcinogenic risks of elements in samples for dermal exposure. But the cancer risk values of Cr (HQ > 1 for ingestion) in brown color lipsticks and Ni indicate that lipsticks have some carcinogenic effects if they enter the user's body. Dermal cancer risk for eye pencils has also been calculated and for Pb, Cr, Ni, and As; the values were found within the acceptable ranges of 10-6-10-4. It is suggested that the allowable limit of all toxic elements in cosmetics must be established. Furthermore, continuous monitoring is urgently needed for personal care products like lipsticks and eye pencils commonly available in the local markets in the country like Bangladesh.

Distribution, sources, and pollution levels of toxic metal(loid)s in an urban river (Ichamati), Bangladesh using SOM and PMF modeling with GIS tool.

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.

Spatial distribution, water quality, human health risk assessment, and origin of heavy metals in groundwater and seawater around the ship-breaking area of Bangladesh.

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.

Characterization of microplastic pollution in the Pasur river of the Sundarbans ecosystem (Bangladesh) with emphasis on water, sediments, and fish.

An emerging concern of today's world, due to their universal dispersion worldwide, is the environment's microplastic pollution. The Sundarbans, the world's largest mangrove, have unique and dynamic environmental settings with numerous pollution risk exposures, including microplastics (MPs). Thus, the present study has focused on the MP pollution in water, sediment, and fish samples of the Sundarbans of Bangladesh for the first time. Water and sediment samples were collected (n = 30/each) from sampling locations along the Pasur river (Bangladesh). Furthermore, nine species of fish samples were collected from a local fish market situated at the Mongla port. Results show that 100 % of the analyzed samples have evidence of MPs. On average, 2.66 × 103 plastic particles/L and 1.57 × 105 particles/kg were found in water and sediment samples, respectively. Furthermore, results show a higher number of MPs in the animals' gastrointestinal tract (GIT) (10.41 particles/g), concerning the average concentration recorded in the muscles (4.68 particles/g). O. pama and H. nehereus were the species that showed the highest MPs accumulation in the GIT. In the muscles, the highest MP levels were observed in T. ilisha and L. calcarifer. Most of the particles were smaller than 1 mm; black-colored particles dominated the pool. FT-IR analysis revealed the presence of seven polymer types where polyamide was abundant in water and sediment samples. SEM analysis showed morphological structures and adsorbed particles on the surface of plastic samples, and the spatial distribution of MPs indicates that the location with high human intervention has elevated levels of MPs. Therefore, our study demonstrates that Sundarbans mangrove forests are highly contaminated with MPs and that its fisheries can be a potential source of human exposure to these pollutants.

Human exposures to multiple water sources in the southwestern coastal region of Bangladesh: water quality, pollution sources, and preliminary health risks appraisals.

The coastal areas of Bangladesh have poor accessibility to fresh drinking water and the groundwater is not suitable for drinking, cooking, and other domestic uses due to high levels of salinity and potentially toxic elements. The current study focuses on understanding of the distribution of some physicochemical parameters (temperature, pH, EC, TDS, and salinity) and chemical elements (Fe, Mn, Zn, Ca, Mg, Na, K, Cu, Co, Pb, As, Cr, Cd, and Ni) with health perspective in drinking water from the southwestern coastal area of Bangladesh. The physicochemical properties of the water samples were examined with a multiparameter meter, while the elemental concentrations were analyzed using atomic absorption spectrometer. Water quality index (WQI) and irrigation indices were utilized to determine the drinking water quality and irrigation feasibility, respectively, whereas hazard quotients (HQs) and hazard index (HI) were used to assess the probable pathways and the associated potential risks to human health. The concentrations of some toxic elements in measured samples were relatively higher compared to drinking water guidelines, indicating that ground and surface water are not apt for drinking and/or domestic uses. The multivariate statistical approaches linked the source of the pollutants in the studied water body mostly to the geogenic origin including saline water intrusion. WQI values ranged from 18 to 430, reflecting excellent to unsuitable categories of water quality. The assessment of human health risks due to exposure to contaminated water demonstrated both carcinogenic and non-carcinogenic health risks in the exposed residents of the study area. Therefore, appropriate long-term coastal area management strategies should be adopted in the study region for environmental sustainability. The findings of this research will be supportive in understanding the actual situation of fresh drinking water in the area for policymakers, planners, and environmentalists to take effective necessary measures to ensure safe drinking water in the study area.