Evaluation of essential and trace metals/metalloids distribution and probable human health risk implications from branded liquid and powder milks available in Dhaka City, Bangladesh.

The processed forms of milk, branded liquid, and power milk available in Dhaka city, the capital of Bangladesh, were investigated for essential and trace metal/metalloids regarding nutritional and human health risk aspects. For this, the potential nutritional contribution, estimated daily intake (EDI) and non-carcinogenic risk for six different life stages with male and female categories, as well as the carcinogenic risk for children and adults of both genders, were addressed. In total, 46 branded liquid and powder milk samples were considered for this analysis employing atomic absorption spectroscopy. The concentration of essential elements showed the trends of K > Ca > Na > Mg > Fe > Zn > Mn > Cu and K > Ca > Na > Mg > Fe > Cu > Mn > Zn for liquid and powder milk samples, respectively, but the potentially hazardous one showed the same trends (Cr > Pb > Hg > As > Cd) for both items. Except for Cr, Hg, and Fe, the elemental compositions of both milk categories differed considerably (< 0.05). Compared to the threshold values for milk samples (liquid and powder), Fe (19% and 27%), Mn (100% and 63%), Cu (0% and 23%), Zn (94% and 0%), Pb (25% and 13%), and Cr (0% and 3%) showed above the permissible limits. The nutrient input was the highest for Ca (27.2% and 18.7%), followed by Mg, K, and Na. The EDI of studied elements was within the daily permissible limit in both the milk category (except age group (≤ 3) and the female category). The non-carcinogenic risk assessment showed that the age groups ≤ 3 for liquid milk and ≤ 3 and 3 < X ≤ 14 with female categories for powder milk exceeded the threshold level (> 1) in the case of Cr, Cd, As, Zn, and Mn. The probable carcinogenic risks indicated an unacceptable risk level (< 1.00E-04) for the ingestion of Cr through powder milk samples for children in male and female categories. Finally, it believes that green cow farming practices and green milk processing technology, as well as continuous monitoring of toxic metals, can limit the ultimate risk worldwide.

Adsorption Mechanism of Methylene Blue by Graphene Oxide-Shielded Mg-Al-Layered Double Hydroxide From Synthetic Wastewater.

Pollution of water resources by various pollutants is a global environmental issue, particularly, dye pollution has a major contribution to it. From various studies, it is confirmed that adsorption is an excellent remediation technique compared to others. Mg-Al-layered double hydroxides (LDHs) intercalated with NO3- ions act as an effective adsorbent-removing ionic species like heavy metal and dyes. Another popular nanomaterial is graphene oxide (GO), which is successfully used as an adsorbent for different pollutants like dye and heavy metal ions. It is prepared based on the modified Hummers method. In this study, GO was introduced on the surface of LDH to improve its adsorption capacity. The adsorption process is well described by the Freundlich model. The maximum adsorption capacity was obtained at around 0.5 and 0.85 mmol of methylene blue (MB) per gram of Mg-Al LDH and modified Mg-Al LDH with GO, respectively. The reaction kinetics of MB with both adsorbents is determined to be the pseudo-second-order. To get more insights of the mechanism, molecular dynamics (MD) simulation was conducted among the modified Mg-Al LDH with GO and MB molecules at both low- and high-concentration environments, which demonstrated that the developed composite adsorbs MB molecules predominantly onto its GO surface and then the MB molecules are adsorbed by the LDH surface. C-H···O (2.49-3.04 Å) and pi-donor···H-O (2.45-3.05 Å) are the major driving forces behind the strong adsorbability. Besides, S···H-O, S···O,N···O-H, pi···lone pair, pi···sigma, pi···cation, and alkyl···hydrophobic interactions play important roles in stabilizing the MB molecules onto the surface of the composite.

Concentration of heavy metals in seafood (fishes, shrimp, lobster and crabs) and human health assessment in Saint Martin Island, Bangladesh.

A contaminated aquatic environment may end up in the food chain and pose risks to tourist health in a tourist destination. To assess the health risk for tourists that visit St. Martine Island, which is a popular domestic and foreign tourist destination in Bangladesh, a study is undertaken to analyse the level of heavy metal contamination from chromium (Cr), manganese (Mn), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg) and iron (Fe) in six of the most consumed fish (L. fasciatus, R. kanagurta, H. nigrescens, P. cuneatus, P. annularis and S. rubrum) and five crustacean species, which consist of a shrimp (P. sculptilis), a lobster (P. versicolor) and three crabs (P. sanguinolentus, T. crenata and M. victor) captured. The samples were analysed for trace metals using atomic absorption spectrometer, and the concentrations of the metals were interpreted using the United State Environmental Protection Agency (USEPA) health risk model. The muscle and carapace/exoskeleton of shrimp, lobster and crabs were analysed and contained various concentrations of Pb, Hg, As, Cr, Cd, Fe, Cu, Zn and Mn. The hierarchy of the heavy metal in marine fish is Fe > Cd > Zn > Pb > Cu > Cr > Mn > Hg. The concentrations of Pb in the species R. kanagurta, H. nigresceus and S. rubrum were above the food safety guideline by Australia, New Zealand and other legislations in most marine fish and crustaceans. Crabs showed higher mean heavy metal concentrations than shrimp and lobster. Acceptable carcinogen ranges were observed in three fish species (R. kanagurata, H. nigresceus and S. rubrum) and one crustacean species (P. sculptilis) samples.

Lead Exposure of Four Biologically Important Common Branded and Non-branded Spices: Relative Analysis and Health Implication.

Technological advances and socioeconomic development of Bangladesh are leading to the best choice between branded and non-branded powdered spices. But toxic metal issues can be another factor to elect them. So lead (Pb) exposure and its consequence on the human body for these two categories of four common spices have been ascertained here. A validated laboratory method using hot plate digestion and flame atomic absorption spectrometry (FAAS) has been used for that. The obtained mean concentration of Pb in branded and non-branded spice powders followed the decreasing order of turmeric > coriander > red chili > cumin powder and turmeric > red chili > cumin > coriander powder, respectively, where, in any analysis mode, the non-branded items are potentially ahead of Pb exposure. The market-based mean concentration between these two categories was not a significant difference (t-test). Approximately 90% of the spice samples have shown within the maximum allowable limit by Bangladesh Standard. The sum of estimated daily intake indicated that most of the city market (67%) for non-branded items and some branded (33%) samples have crossed the maximum tolerable daily intake (> 0.21 mg/kg). So, the human health risk assumption for the inhabitant of studied areas suggests there is no significant level of risk for them due to the consumption of spices regarding non-carcinogenic risk factor (THQ and total THQ) and carcinogenic risk factor (CR). But the development of a quality control process for loose spice powders as well as toxic metal screening from raw materials to finish products urgently needed and continuous monitoring with identifying the source of toxic metal is highly recommended.

Pollution Characteristics, Source Identification, and Health Risk of Heavy Metals in the Soil-Vegetable System in Two Districts of Bangladesh.

The consequences of climate change, food security, and self-sufficiency goals are driving excessive human activity onto vegetable farms in Bangladesh, and harmful heavy metal exposure is spreading. So, the study assessed the toxic metals (Pb, Cd, and Cr) exposure, characteristics, and human health risk regarding the soil-vegetable system of two distinct locations in Bangladesh using atomic absorption spectrometry. The average concentration of metals in soil and fertilizer/pesticide samples followed the same order (Cr > Pb > Cd), but for vegetable samples, the order was Pb > Cr > Cd, with some extra Pb compared to the World Health Organization (WHO) allowable limit (0.3 mg/kg). Low levels of pollution with negligible ecological concerns were predicted for both locations by the soil quality indexing. But industrial influence boosted the Pb content in location B, and common sources (fertilizer/pesticide) for both locations might be responsible for a moderate level of Cd. The toxic metals transferred to vegetables followed the trend of Cd > Pb > Cr. However, the human health risks arising from harmful metals exposure at both locations were ineffective (< 1) in evaluating noncarcinogenic risk patterns through the target hazard quotient (THQ), total THQ, and hazard index (HI). Again, considering probable carcinogenic risk patterns, vegetable consumption with studied exposure levels of toxic metals followed within the acceptable range (between 1.0E-04 and 1.0E-06). Overall, location B is slightly more vulnerable than location A by considering metal exposure, pollution distribution, and risk evaluation in the study area (significant at p < 0.05). So, systematic monitoring and protective measures are required to ensure food safety and sustainable vegetable production.

Exploration of Toxic and Essential Metals in Popular Rice Grains of Bangladesh and Associated Human Health Risk Implications.

In order to evaluate the benefits as well as the impacts of essential and toxic metals regarding human health, the six common rice grains (katarivhog, bashful, banglamoti, najirshail, branded miniket and loose miniket) were collected from four wholesale markets in Dhaka, the capital of Bangladesh, and were analyzed with different atomic absorption spectroscopy (AAS) techniques. The mean concentrations of the toxic metals Pb, Cd, Cr, and As had 0.299 ± 0.017, 0.157 ± 0.012, 1.33 ± 0.084, and 0.120 ± 0.006 mg/kg, respectively, while those of the essential metals Fe, Cu, Zn, Na, Ca, and Mg had 7.90 ± 0.447, 3.11 ± 0.097, 10.6 ± 0.340, 37.4 ± 0.622, 90.1 ± 7.70, and 115.8 ± 1.61 mg/kg, respectively. Among them, the mean concentrations of toxic metals (Pb, Cd, Cr, and As) exceeded the maximum allowable concentration in rice set by the Codex Alimentarius Commission (CAC). Risk assessment of the heavy metals Pb, Cd, Cr, As, Fe, Cu, and Zn showed that their estimated daily intakes were below the daily reference doses for adults. However, Cd and Cr individually were found to have the target hazard quotient value close to 1 (threshold limit), indicating that they alone are capable of potential health hazards from continuous rice consumption, while the hazard index has surpassed three units signifying greater danger associated with the current trend of consumption. A very high chance of developing cancer in the near future is predicted by incremental lifetime carcinogenic risk (ILCR) analysis for continued intake of Cr (ILCR > 1E-03), and a moderate to high risk is predicted for other carcinogenic substances (Pb, Cd, and As) (ILCR in between 1E-03 and 1E-05) with present rice consumption. The contribution of the essential metals to the RNI revealed that Cu from rice contributes more than 100% in most samples, and the overall contribution is in the following order: Cu > Zn > Fe > Mg > Ca > Na. To ensure the safety of staple foods for human health, it ought to be necessary to design a plan to measure the budget of hazardous metals from all sources with proper surveillance by relevant authorities.

Source apportionment, ecological, and human health risks of toxic metals in road dust of densely populated capital and connected major highway of Bangladesh.

This study investigates pollution levels, source apportionment, ecological, and human health risks associated with toxic metals (Pb, As, Hg, Cr, and Cd) in road dust from the most populated Dhaka city and a connected major highway in Bangladesh. The mean concentration of Pb, Hg, and Cd were 1.3, 29.3, and 13.2 times higher than their corresponding background values with spatially uneven distribution all over the study area. Metal pollution indices, the geo-accumulation index (Igeo), NIPI, and PI, indicated extreme contamination at many sites depending on local environmental factors. The potential ecological risk ([Formula: see text] revealed that 84% and 54% of samples showed the extreme ecological risk for Hg and Cd pollution, respectively. On the other hand, the potential ecological risk index (PERI) and Nemerow integrated risk index (NIRI) showed that most sampling sites suffered high to extreme ecological risk. Source apportionment using positive matrix factorization (PMF) identified coal combustion, and gasoline (50.14%), traffic exhaust (35.26%), and industrial and agriculture activity (14.60%) were the main source of toxic metals of the study area. Non-carcinogenic health risk indicated that adults are more vulnerable than children, and hazard index (HI) of Hg for both age groups and Cd for adults were significantly higher than the safe level. The carcinogenic risk (CR) levels of toxic metals were acceptable (10-6 to 10-4), although the maximum limit of Cr for children and As for adults was close to the unacceptable limit (10-4). Continual exposure to toxic metals through road dust might develop lifetime cancer risk in local inhabitants.

Appraisal and validation of a method used for detecting heavy metals in poultry feed in Bangladesh.

Background and Aim: Low concentrations of heavy metals are toxic and pose a serious threat to human health and the environment. Therefore, regular assessments of the toxic metal content in poultry feed are crucial for evaluating feed quality and customer safety. It is difficult to determine the heavy metals in the poultry feed at the trace amount. Therefore, this study aimed to validate this method through the detection of three heavy metals, chromium (Cr), cadmium (Cd), and lead (Pb), in poultry feed samples. Materials and Methods: Graphite furnace atomic absorption spectrometry (GF-AAS) method was used to analyze the heavy metals in poultry feed according to the guidelines given by the Council Directive 333/2007/EC, Commission Decision 657/2002/EC. In this study, various parameters such as linearity check, limit of detection (LOD), limit of quantification (LOQ), recovery percentage, precision checks, repeatability, reproducibility, and uncertainty measurement were considered to validate and assess the method following international guidelines. Heavy metals, such as Pb, Cr, and Cd, were analyzed from the feed samples in the laboratory using the GF-AAS method (Model: AA-7000 Shimadzu, Japan) with high purity argon as the inert gas, and the absorbance was read at wavelengths of 283.0, 357.9, and 228.8 nm, respectively. Results: The coefficient of variation (CV%) for system suitability and precision data was <10% for all the metals (Pb, Cr, and Cd) detected in this study. The overall CV% of repeatability and reproducibility ranged from 8.70% to 8.76% and 8.65% to 9.96%, respectively. The linearity of the calibration curves was excellent (r2 > 0.999) at various concentration levels for the three different metals. The recovery (%) was found to be 94.53, 93.97, and 101.63% for Pb, Cr, and Cd, respectively. The LOD values in feed were 0.065, 0.01, and 0.11 mg/kg, and the LOQ values were 0.22, 0.03, and 0.38 mg/kg for Cr, Cd, and Pb, respectively. The values recorded for the measurement uncertainty (%) were 11.48, 4.43, and 12.42% for Cr, Cd, and Pb, respectively. Conclusion: The results show that these study criteria or parameters have met the validated or acceptable range. Therefore, it is a reliable technique that can be used undoubtedly for the routine analysis of heavy metals in poultry feed samples across the globe.

Concentration, source identification, and potential human health risk assessment of heavy metals in chicken meat and egg in Bangladesh.

Chicken meat and hen egg are very popular foodstuffs around the world and highly consumed as curry, fast food, processed food, etc. assuming a promising source of protein. In the present study, the concentrations of Pb, Cd, Cr, As, Hg, Mn, Fe, and Zn in nationally representative samples of chicken meat and hen egg were determined and found in the range of 0.03-2.73, 0.01-0.015, 0.025-0.67, 0.04-0.06, 0.01-0.015, 0.15-0.63, 2.50-38.6, and 1.02-19.4 mg/kg-fw, respectively. The results demonstrated that only Pb exceeded the maximum allowable concentration (MAC) for dietary food. Multivariate statistical analyses depicted that anthropogenic activities were the major source of heavy metals in the investigated foodstuffs. Human health risks associated with the dietary intake of these metals through the consumption of chicken meat and hen egg were evaluated in terms of estimated daily intake (EDI), non-carcinogenic risk of individual heavy metal by target hazard quotient (THQ), total target hazard quotient (TTHQ) for combined metals, and carcinogenic risk (CR) for lifetime exposure. The calculated values of EDI, THQ, TTHQ, and CR were below their respective permissible benchmarks indicating the safe consumption of the investigated foodstuffs with respect to heavy metal contamination.

Heavy Metals Accumulation in Tissues of Wild and Farmed Barramundi from the Northern Bay of Bengal Coast, and Its Estimated Human Health Risks.

Globally, both natural water bodies and aquaculture systems are being severely contaminated by heavy metals due to rising anthropogenic activities. Fish living in aquatic environments can easily accumulate metals in their bodies, which can then be transferred to consumers and put them at risk. In this study, metal concentrations (Pb, Cd, Cr, As, Mn, Cu, Zn) in different organs (gill, liver, and muscle) of farmed and wild Barramundi (Lates calcarifer) fish from the northern Bay of Bengal were evaluated to quantify and compare contamination levels and related human health risk. Heavy metal concentrations were higher in liver tissues of farmed Barramundi than in wild Barramundi, with the following relative mean values in the liver, gills, and muscle: Zn > Cu > Pb > Mn > Cd > Cr > As; Zn > Cr > Cu > Pb > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; and Zn > Pb > Cu > Cr > Mn > Cd > As, respectively. The differences in heavy metal accumulation observed between farmed and wild fish were probably related to the differences in their environmental conditions and dietary element concentrations. However, ANOVA indicated that the variation of metals in wild and Barramundi was not statically significant. Pb concentrations in the liver tissue of farmed Barramundi exceeded the national and international threshold limits, whereas concentrations of other metals were within the limit. Among the examined organs in both fish species (wild and farmed), muscle had the lowest concentration compared to others, and liver was the target organ for Pb, Cu, and Cd accumulations. Metals such as Zn and Mn exhibited higher concentration in the gills. However, all the studied heavy metals were below the maximum permissible limits of national and international standards, but the mean concentrations of Pb and Cd values in the liver of farmed Barramundi exceeded all international and national guidelines. Based on the contamination factors (CF) and pollution indices (PLI and MPI), the degree of contamination in the fish organs was as follows: gills > liver > muscle. The major accumulation tissues for both farmed and wild fish were found to be the gills (MPI = 0.970) and the liver (MPI = 0.692). Based on the estimated daily intake (EDI), the fish samples examined in this study are safe for human consumption as within the recommended daily allowance (RDA) range established by various authorities. According to the Target Hazard Quotient (THQ) and Carcinogenic Risk (CR) calculations, though the Barramundi fishes depicted no potential hazard to humans, farmed fish posed a higher health risk than wild fish.

Groundwater quality and human health risk assessment in selected coastal and floodplain areas of Bangladesh.

Groundwater aquifers are a common source of drinking water in Bangladesh. However, groundwater contamination is a major public health concern across the country. This research aims to examine the groundwater quality and health concerns using a random sampling process. Multivariate statistical and health risk analyses of elements were performed to determine the source of contaminants and their effects on human health. A total of 24 parameters were analyzed, where Na+, NH4+, K+, Mg2+, F-, NO3-, Mn, Fe, Se, U, and As concentrations were found to be high in different sampling points compared to the Department of Environment of Bangladesh (DoE), and the World Health Organization (WHO) groundwater quality standards. Principal Component Analysis (PCA) and Cluster Analysis (CA) identified the dominant and potential sources of contaminants in the groundwater aquifer, including geogenic, salinity intrusion, industrial, and agricultural. The results of the degree of contamination level (Cd) and the heavy metal pollution index (HPI) showed that 28% and 12% of the sampling points had high levels of heavy metal contamination, indicating a high risk for human health issues. Cr concentrations were found to have a higher carcinogenic (cancer) risk than As and Cd concentrations. Hazard quotient (HQ) and hazard index (HI) scores expressed the hazardous status and possible chronic effects in the context of individual sampling points. For both child and adults, 44% and 36% of the sampling points had a high HI score, indicating the possibility of long-term health risks for local populations.

Chemometric appraisal of water quality for domestic and agricultural purposes: a case study from establishing Rooppur Nuclear Power Plant (NPP) area, Pabna District, Bangladesh.

Water is the main sources for domestic purposes and as well as for both farming and industrial activities. Therefore, this study investigated the quality of groundwater at Ishwardi, Pabna district of Bangladesh. This study showed that the heavy metals such as Pb, Cd, Cr, As, Ni, Cu, Zn, and Fe were remaining in trace amount. The groundwater quality index (GWQI), heavy metal evaluation index (HEI), heavy metal pollution index (HPI), and degree of contamination (Cd) revealed that all of the groundwater samples belonged to good quality condition for drinking purposes. Nevertheless, Cd provided better index than other indices. Subsequently, hazard quotient (HQ) and hazard index (HI) values for heavy metals indicated that there was no significant noncarcinogenic health risk due to oral ingestion of groundwater except three sites. However, the paired student t-test ([Formula: see text]) revealed that child was found to be more exposed compared to adult for noncarcinogenic health risk due to oral ingestion of the same groundwater samples. This study revealed that pH, EC, TDS, salinity, Na+, K+, Mg2+, Ca2+, Cl-, SO42-, PO43-, and NO3- values in water samples are in tolerable limit according to Bangladesh (DoE) and international standards (WHO, IS, FAO, USEPA, UCCC). Subsequently, combined approaches of numerous irrigation water quality indices, sodium adsorption ratio (SAR), soluble sodium percentage (SSP), total hardness (TH), residual sodium carbonate (RSC), and Kelley's ratio (KR), were applied to appraise the appropriateness of water for farming purposes. The irrigation water quality index (IWQI) revealed that majority of the groundwater samples were suitable for agricultural purposes. Classification based on Wilcox and US salinity hazard diagram indicated a consistent conclusion, which indicated that the water quality was in good condition for farming in the study area.

Investigation of the possible sources of heavy metal contamination in lagoon and canal water in the tannery industrial area in Dhaka, Bangladesh.

This study evaluated the heavy metal pollution level of tannery effluent-affected lagoon and canal water in the southwestern Dhaka, Bangladesh. The measured physicochemical parameters (electrical conductivity, chemical oxygen demand, pH, SO²â»4, PO³â»4, Cl-, and NO⁻3) and metals (As, Ca, Cd, Co, Cr, Cu, Fe, K, Mn, Ni, Pb, and Zn) were subjected to principal component (PCA) and hierarchical cluster analyses, and examining correlation matrix as well in order to explain the behavior and sources of the parameters/metals. The mean concentrations of the heavy metals in the lagoon and canal water were very high and, in most cases, exceeded the standard limits recommended by the Bangladesh Government. The following elemental associations were obtained from PCA and CA: Ca-Cd-Cr-Fe-K-Mn-Pb-Zn, Co-Cu-Ni, and As, which could be linked to anthropogenic sources (i.e., processes of the tannery and paint industries with some contributions from the municipal waste system). Potassium, Ca, Cr, Mn, Fe, Zn, As, and Cd occurred as important anthropogenic markers in the lagoons and lower part of the canal. Copper, Co, and Ni were importantly distributed in the lower part of the canal, which also received metal inputs from the municipal waste and other industrial sources, including paint industry. GIS-based factor score maps, generated to show the spatial controls of the major processes affecting surface water hydrochemistry, suggest that the activities of paint and tannery industries and municipal sewage are pervasive processes in the area, whereas the contribution from pesticides (used for tanning and disinfecting hides) has localized effects. This study has provided the evidence that effluents discharged from the tannery and auxiliary industries and urban sewage system are the main sources of heavy metal pollution in the lagoon and canal water systems in the Hazaribagh area of southwestern Dhaka. The high mean concentrations (in mg/l) of Cr (5.27), Pb (0.81), As (0.59), and Cd (0.13) observed in the water samples may have serious public health and potential environmental hazard implications.

Health risk estimation of metals bioaccumulated in commercial fish from coastal areas and rivers in Bangladesh.

Metal contaminations in commercial fish have become a great public health concern worldwide including Bangladesh. The current study was conducted to provide preliminary evidence of nine metals in three commercially significant fish namely Pampus argenteus, Sardinella longiceps and Tenualosa ilisha collected from four coastal stations- Kuakata, Pathorghata, Cox's Bazar, and Pirojpur, and eight stations of five rivers- Padma, Meghna, Jamuna, Katcha, and Nobogonga in Bangladesh. High magnitudes of Pb (0.74-4.59 mg/kg ww), Cd (0.07-0.24 mg/kg ww), and Mn (0.45-2.03 mg/kg ww) were recorded in the sampling stations that exceeded the maximum permissible limits (MPL) proposed by different recognized organizations. Significant mean differences of metal concentrations were observed (p < 0.05) between species and stations. In fish samples, excessive metals accumulations were recorded from Kuakata (St.1) at the coastal area, and Nobogonga (St. 12) among the rivers. The health risk assessment (HRA) was carried out comprehensively via the estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR) calculations. The outcomes of EDI, THQ, and HI suggest that chronic exposure to towering Pb content might pose potential health threats to inhabitants particularly living in highly polluted stations of the coastal area. In addition, the massive TR values of Cd intake through fish consumption from the coastal area might create cancer risks. Accordingly, the ingestion of metals contaminated fish portends chronic as well as acute health risks to Bangladeshi people living both at home and abroad.

Accumulation of Trace Metals in Indigenous Fish Species from the Old Brahmaputra River in Bangladesh and Human Health Risk Implications.

In this study, accumulation of the top six most toxic trace metals (Arsenic (As), Cadmium (Cd), Chromium (Cr), Mercury (Hg), Nickel (Ni) and Lead (Pb)) were assessed in six indigenous fish species (Barilius barila, Salmostoma acinaces, Gudusia chapra, Labeo bata, Corica soborna, and Sperata aor) collected from the Old Brahmaputra River in Bangladesh. Human health risk associated with these fish consumption was also evaluated. Metals were analyzed in whole body of fish by an atomic absorption spectrometer (AAS). Mean concentrations of metals (µg/g, wet weight) were in the range of As (< 0.02-0.278), Cd (< 0.002-0.005), Cr (0.239-0.761), Hg (0.008-0.057), Ni (< 0.02-0.044), and Pb (< 0.01-0.038). The metal contents varied significantly among the fishes regarding their feeding habits and living habitats. Concentrations of As, Cr, Hg, and Pb were significantly higher in omnivorous species, whereas the benthopelagic species showed significantly higher accumulation of As (p < 0.05). The target hazard quotient (THQ) for noncarcinogenic risk and target cancer risk (TR) for carcinogenic risk were calculated to estimate the probabilities of experiencing these adverse health effects for the fish consumers. Metal-specific THQ values were all below 1 indicating no potential human health risk. Nonetheless, the hazard index (HI) values to estimate the effects from exposure to all metals collectively elucidated chronic noncarcinogenic health risk particularly from G. chapra consumption. The TR values revealed that there was carcinogenic risk from exposure to As through consumption of the fish. This study finally suggests a systematic and continuous monitoring of trace metal contamination in fishes from the river to ensure the fitness of this food item regarding the safety for human health.

Ecological risk and source apportionment of heavy metals in surface water and sediments on Saint Martin's Island in the Bay of Bengal.

The study aimed to determine eight hazardous heavy metals in surface water and sediment samples collected from the Naf River, Shah Porir Dwip (estuary), and mostly around Saint Martin's Island in the Bay of Bengal. The results of heavy metals in water samples were ranged as Pb 14.7-313.0, Cd 33.0-70.0, Cr < 11.0-37.0, Cu 38.0-57.0, Zn 26.8-69.2, Ni 102.0-285.0, and Hg 0.3-1.6 µg L-1. The concentrations of metals in sediment samples were ranged as Pb < 10.0-37.5, Cd 0.2-1.0, Cr < 5.0-30.1, Cu < 3.0-30.9, Zn 24.1-88.0, Ni < 4.0-48.3, As 0.1-7.3, and Hg < 0.01-0.08 mg kg-1 dw. Ni and Cr were strongly correlated, suggesting that this pair of metals might diffuse from a common origin. The contamination factor (Cif) demonstrated that sediment samples were mostly contaminated by Cd and slightly contaminated by Pb and Zn. The geoaccumulation index (Igeo) revealed considerable values for Cd on Saint Martin's Island. Cd as a single regulator posed moderate to considerable risk frequently among the sampling stations. Pollution load index (PLI) values remained below 1 (< 1), which indicated a decrease from baseline pollution value among all stations. However, potential ecological risk (PER) was graded for two stations (St1 and St13) with a moderate-risk zone due to the Cd contribution. However, shipping emission and lithogenic sources were the most predominant for heavy metals in the sediment, which were determined by applying the principal component analysis-absolute principal component score (PCA-APCS). Graphical abstract.

Variability of water quality and metal pollution index in the Ganges River, Bangladesh.

The Ganges River is one of the biggest transboundary streams in the Indian sub-continent. The significant part of this waterway channel drains one of the most densely populated areas on the planet so it is unequivocally influenced by human activities. Unprecedented high-temporal-resolution samples were collected for investigating the seasonal variability of water quality. Water quality index (WQI) reveals large seasonal variation among three major seasons and also indicates that the river water is not suitable for drinking and other household uses. The dominant water facies is bicarbonate (HCO3-). The water quality indices, %Na, Kelley's ratio (KR), sodium adsorption ratio (SAR), and magnesium adsorption ratio (MAR), reveal that the water is appropriate for irrigation. The permeability index (PI) indicated that the water is moderate to poorly useable for agricultural purposes. Heavy metals concentrations demonstrated significant seasonal variations with high concentrations during the monsoon due to flushing of pollutants from catchment areas by intense monsoonal precipitations. In addition, local activities such as oil spills from the boat, vehicle washing water, and agricultural runoff may also added pollutants. The single-factor pollution index (Ii) and Nemerow pollution index (Ni) exhibits minor pollution. The values of heavy metal pollution index (HPI) are far below than the critical limit (100) for the studied month, although relatively higher HPI values found for April, August, and November than other months might come from domestic wastes and agricultural activities. The heavy metal evaluation index (HEI) values of all the months indicated a low degree of pollution. Even though the river water pollution level is low, the authority should take proper management and monitoring strategy for sustainable use.

Groundwater salinization and associated co-contamination risk increase severe drinking water vulnerabilities in the southwestern coast of Bangladesh.

Household drinking water security is one of the major issues among coastal communities in Bangladesh. To examine the groundwater quality and social consequences, groundwater samples and household questionnaires were administered across the study area. Instrumental and statistical tools were used to analyze the water quality and social survey data. The average concentrations of electrical conductivity (EC) (7135.67 µS/cm), total dissolved solids (TDS) (3691 mg/L), Na+ (1569.51 mg/L), Ca2+ (289.5 mg/L), Mg2+ (340.51 mg/L), Cl- (2940.78 mg/L), F- (11.85 mg/L), NO3- (54.44 mg/L), NO2- (162.95 mg/L), PO43- (105.19 mg/L), Fe (4.9 mg/L), Mn (1.22 mg/L), As (16.55 µg/L), B (833.28 µg/L), and Pb (34.22 µg/L) were observed in groundwater, and exceeded the drinking water standards from 30% to 100% depending on the sampling location. Thus, the remarkably high contents of EC, TDS, Cl-, and Na+ represented possible saltwater intrusion along the coastal aquifer. The positive correlations between EC and trace and toxic elements indicated the potential influence of groundwater salinization on the dissolution of more chemical contaminants in the aquifer. These results showed that 100% of samples were unsuitable for drinking purposes. Severe drinking water scarcity is a serious issue, and local people have been affected by water-related diseases owing to the long-term consumption of contaminated water. Salinity problems in drinking water and related health diseases have increased significantly in the past several years. In addition, climate change and its associated hazards, including sea-level rise, cyclonic storm surges, flooding, and resulting inundation problems, have intensified the drinking water scarcity and health problems at the community level. To ensure household water security, environmental exposure, hydrogeology, and anthropogenic interventions must be considered to determine future sustainable water policies.

Morning (First) Urine Copper Concentration: a New Approach for the Diagnosis of Wilson's Disease.

Twenty-four-hour (h) urinary copper content is considered as the most suitable tool for the diagnosis of Wilson's disease (WD); however, it is less accurate, time-consuming, and non-economical. Consequently, in the present study, an alternative method through measuring the morning (first) urine copper (Cu) concentration is proposed for the diagnosis of WD, which is more accurate, precise, faster, and cheaper. For this purpose, a sensitive, accurate, and precise analytical method was developed and validated in regard to Commission Decision 657/2002/EC, Council Directive 333/2007/EC, ISO/IEC 17025:2005, and EURACHEM 1998 for the determination of Cu in urine using flame atomic absorption spectrometry (FAAS). The methods LoD and LoQ for urine Cu were estimated as 6.68 µg/L and 16.7 µg/L respectively. The accuracy of the method was found to be 93.70-101.88% calculated from the spike recovery experiment. The RSDs for the repeatability and reproducibility precision were measured as 0.67-3.16 and 0.26-1.95 respectively. The method validation performance criteria indicated that the method was suitable for the determination of Cu in urine. The validated method was then applied for the determination of Cu in both 24 h and first urine. From the analysis, it was found that the amount of Cu per liter in the first urine was almost equivalent to the amount of Cu per 24 h indicating that instead of considering the 24-h urine, morning (first) urine investigation might be an alternative approach for the diagnosis of WD.

Evaluation of Possible Human Health Risk of Heavy Metals from the Consumption of Two Marine Fish Species Tenualosa ilisha and Dorosoma cepedianum.

In order to study the effects of contaminants on human health, fish is considered as a powerful model among all available species for risk-benefit assessments. Tenualosa ilisha and Dorosoma cepedianum are two fish species of great economic importance as they are found in undeveloped, developing and developed countries. Concentrations of heavy metals lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As) and mercury (Hg) were determined using validated and accredited test methods in order to assess the potential human health risk from the dietary intake of these two selected fish species. The estimated daily intake (EDI) of all the five heavy metals was measured from the consumption of the two species considering the mean fish consumption of 61 g person-1 day-1 defined for European population. The EDI indicates that no risk to people's health with respect to the EDI of Pb, Cd, Cr, As and Hg through the consumption of the two fish species. The estimation of target hazard quotient (THQ) demonstrating the non-carcinogenic risk indicates that intake of Pb, Cd, Cr and Hg through the consumption of two fish species is safe for human health, whereas, consumption of As suggests potential risk to consumers. The estimation of carcinogenic risk of Cd, Cr and As due to the consumption of two selected fish species indicates that consumers remain at risk of cancer. Thus, these fish species should not be considered safe for human consumption.