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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]

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]

Trace metals concentration and proximate composition of raw and boiled silver pomfret (Pampus argenteus) from coastal area and retail market were determined to gain the knowledge of the risk and benefits associated with indiscriminate consumption of marine fishes. The effects of cooking (boiling) on trace metal and proximate composition of silver pomfret fish were also investigated. Trace element results were determined by the Energy Dispersive X-ray Fluorescence (EDXRF) Spectrometer wherein fish samples from both areas exceeded the standard limits set by FAO/WHO for manganese, lead, cadmiumm and chromium and boiling has no significant effects on these three metal concentrations. Long-term intake of these contaminated fish samples can pose a health risk to humans who consume them. [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]