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The study assessed the composition, health risk, and sources of trace elements of road dust collected from three major metropolitan cities in Bangladesh. Pellets were prepared from the collected road dust samples and analyzed by the Energy Dispersive X-ray Fluorescence. The mean concentration of trace elements showed the order of K > Fe > Ca > Ti > Mn > Zr > Sr > Zn > Rb > Cr > Rb > Cu > Pb > Y > As > Ni. This research also presented the spatial distribution of the metals among three cities. The contamination factor and degree of contamination were assessed. The highest contamination factor was observed near BSRM steel manufacturing company, Chattogram could be due to the increased traffic in front of this industry. All the sampling sites showed pollution load index lower than one indicating unpolluted. However, K, Zn, and Zr showed a pollution load index values more significant than one. The result indicated that the ecological risk factor (Er) values fluctuated among metals tested across metropolitan cities. Negative geo-accumulation indexes were found for all the elements except K and Zn, suggesting moderate pollution. The Hazard Quotient values of all metals are < 1 for both adults and children. The cancer risks associated with Cr, Co, Ni, As, and Pb have been estimated individually for children and adults. The cancer risks associated with trace elements are below the European Union's acceptable limit, indicating that these five elements are not carcinogenic. The findings of principal component analysis followed by multiple linear regression showed that the sources of heavy metals were mixed natural (34.25%) and anthropogenic sources, vehicle emissions (38.92%), natural sources (5.80%), industrial sources (11.02%) and agricultural sources (10.02%). Four factors were concluded as sources of heavy metals confirmed by applying the positive matrix factorization model such as anthropogenic, industrial activities, natural process and agricultural activities. [ABSTRACT FROM AUTHOR]

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

In recent decades, water quality is a great concern for the human being as it is the most important natural resource but water is polluted by increasing population activities. In this study, surface water samples were collected in the wet and the dry season from Halda River, Bangladesh, and 12 physicochemical properties and 10 traces elements (Cd, Cr, Mn, Fe, Co, Cu, Zn, As, Pb, and Hg) were analyzed to assess the metal toxicity, identify the possible sources, and determine possible carcinogenic and noncarcinogenic risk for adults and child residents. During wet season, the mean concentrations of Cd, Cr, Mn, Fe, Co, Cu, Zn, As, Pb, and Hg were 0.032 ± 0.028, 0.004 ± 0.002, 0.010 ± 0.012, 0.38 ± 0.08, 0.010 ± 0.017, 3.33 ± 1.16, 0.062 ± 0.008, 1.34 ± 1.17, 0.030 ± 0.014, and 0.007 ± 0.002 mg/L, respectively, whereas the concentrations were measured as 0.04 ± 0.017, 0.060 ± 0.036, 0.150 ± 0.134, 0.58 ± 0.11, 0.049 ± 0.017, 0.172 ± 0.166, 0.393 ± 0.212, 1.07 ± 0.989, 0.104 ± 0.121, and 0.003 ± 0.002 mg/L, respectively, during the dry season. The levels of trace elements in water samples were much higher than the guideline values for safe limits of drinking water and the protection of freshwater aquatic life, indicated that water from this river is not safe for drinking and/or cooking purposes. Trace element evaluation index indicated that water was found to be high contamination while ecological risk index showed low to very high contamination. All hazard quotient and hazard index (HI) values were higher than the risk threshold of unity. HI values for child were higher than those for adult, indicating that the health of children is at dramatically higher risk than adults. Arsenic for water ingestion and dermal pathways was the primary contributors to total health risk (HI/THI) indicated that As in surface water of the Halda River might pose health risks to residential users. [ABSTRACT FROM AUTHOR]

The surface salt marsh sediments from marine ecosystems in the Bay of Bengal, Bangladesh was assessed for trace elements like iron (Fe), calcium (Ca), titanium (Ti), potassium (K), strontium (Sr), rubidium (Rb), zirconium (Zr), zinc (Zn), copper (Cu) and lead (Pb), their potential sources, and associated ecological risks. The range of trace elements in sediment (mg/kg) followed the decreasing order: Fe (25020–35176) > Ca (8679–16323) >Ti (2678–3340) > K (23680–16770) > Sr (138.32–209.64) > Rb (124–186.57) > Zr (96.21–161.35) > Zn (37.71–44.95) > Cu (36.51–51.66) > Pb (1.35–10.42). The concentrations of trace elements were under the average shale values of metals in sediment except for Fe, Cu and Rb, which can occasionally be associated with adverse biological effects. Contamination level and ecological risk were evaluated using contamination factor (CF), enrichment factor (EF), geo-accumulation index (Igeo), pollution load index (PLI), and potential ecological risk index (PERI). Multivariate statistical technique was used to classify the metal sources. The results showed that Fe was significantly enriched in the sediments. Ecological risk factors illustrated a pollution-free condition of the salt marsh ecosystem in Bangladesh. [ABSTRACT FROM AUTHOR]

A study was conducted on 16 sites in four Ramsar designated wetlands soils regarding soil properties and pollution indices in the Sylhet basin of Bangladesh. The wetlands sites' soil quality remained favorable for agricultural sustainability. Arsenic and cadmium contents were found at minimum detection levels. Rubidium and zirconium were found below critical levels. Pollution indices revealed that zinc and titanium content is slightly higher than the other elements. It was observed that Fe, Ti, Zr, and Mn originate from natural sources or sediments. In contrast, Zn and Cu originate from the artificial fertilizer sources used in and around agricultural lands of the wetland bodies. Moreover, the wetlands are used only for Boro rice crop, and for most of the year, they remain fallow. As a result, grazing activities are predominant. It is assumed that Cu and Zn are often used as additives for animal feed and enter animal wastes through incomplete absorption, and thus, the application of animal wastes in agriculture causes pollution with Zn and Cu. Pollution load index revealed that 42% of the study sites were polluted and 58% remained unpolluted. Principal component analysis and enrichment factors show that anthropogenic activities are responsible for the current pollution, where Zn and Cu predominate. The wetland sites are being polluted at a minor level. The main reasons for the higher level of metal pollution in Balai wetland might be its geomorphic nature and even anthropogenic activities. This wetland is located at the junction point of the Surma-Kushiyara River in Bangladesh, where an international river, Barak, intersects there, which originated from the upper territory. It is urgent to formulate an integrated action plan to prevent the source points of pollution. [ABSTRACT FROM AUTHOR]

This paper aims to measure the metals (Fe, Cu, Cr, Co, As, Zn, Hg, and Pb) concentration and assesses human health risks posed by these eight metals in the five most available cultured fish species (Pangasiuspangasius, Oreochromisniloticus, Heteropneustesfossilis, Anabustestudineus, Clariasbatrachus) collected from the Mymenshing Sadar Upazila. Both fishes and three fish feeds were analyzed using energy dispersive X-ray fluorescence (EDXRF). In fish feeds, the concentrations of metals were detected in the following order Fe > Zn > Cu > Hg > Pb. Besides, Hg concentration in three feeds samples was found higher than the maximum residue limit. Fe, Cu, Cr, Co, As, Zn, Hg, and Pb concentration in fishes were 82.45 to 104.55, 24.47 to 32.88, 2.62 to 6.73, < 0.28, < 0.41, 70.01 to 96.56, 0.57 to 1.07, and 0.34 to 0.49 µg/g respectively as dry weight basis. Health Risk Index (HRI) was observed > 1 both for adults and children and maximum HRI values for Pb was found in both P. pangasius and C. batrachus fish species. Additionally, PCA explained 73% variation in data and CA comprised the similarity within sampling stations. Pearson correlation implied a strong association amongst the trace metals. Finally, the accumulation of metals tends to the massive health hazard that should be mitigated by adopting several measures on fish feeds. [ABSTRACT FROM AUTHOR]

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

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

• Heavy metals were determined and compared in captured and cultured fishes. • Health Risk Index for Fe, Zn, Cu, Hg and Pb exceeded the safe limit (<1) by USEPA. • The carcinogenic health risk for Pb was higher in cultured fishes than captured fishes. • A risk-based consumption limit of fishes was established. Food toxicity and health risks due to heavy metals exposure through fish consumption have become a major concern for this present era. Since, both cultured and captured fishes are largely consumed in Bangladesh, a comparison of heavy metals between those fishes are must. Seven sample species were collected from a tributary of the Meghna River at Lakhai Kheyaghat, Habiganj, Bangladesh and fish market of Dhaka, Bangladesh. Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometer were used to measure the metal concentrations. The sequence of metal concentration in the flesh of fishes was Fe > Zn > Cu > Pb>Hg for both fish categories with mean concentrations (mg kg−1) of 69.8 ± 7.5 > 56.42 ± 8.59 > 19.52 ± 2.63 > 0.44 ± 0.18 > 0.39 ± 0.04 respectively for cultured fishes (n = 21). Statistically, mean Cu, Zn, and Pb concentrations from captured fishes flesh samples were not significantly different from cultured fishes (p > 0.05) when analyzed with non-parametric Kruskal-Wallis test. Pb carcinogenicity from the cultured fishes was measured a value of 2.5E-05 for children exceeding the prescribed limit by 25 times which indicates a substantial risk for lifelong exposure. Summarizing the results, the Toxicity Scores (TS) has shown substantial rate of possibility for study area inhabitants to be exposed to heavy metals through heavy metal contaminated fish consumption, specially cultured fishes. [ABSTRACT FROM AUTHOR]

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