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Metal/loid pollution from shipwrecking activities has drawn significant concern due to their persistent threat to the marine ecosystem and human health. We investigated the spatiotemporal distribution, pollution characteristics, risks, sources, and potential impact of metal/loids in the sediments and seafood in the Bay of Bengal at nearby open beaching shipwrecking yards in Bangladesh. We collected 78 sediments and 208 seafood samples from the exposed and control sites from 2018 to 2020 during the dry and wet seasons. The concentrations of 16 elements, including cadmium, arsenic, lead, chromium, manganese, copper, zinc, iron, tin, antimony, nickel, cobalt, molybdenum, vanadium, selenium, and thallium were measured using validated inductively coupled plasma-mass spectrometry (ICP-MS) methods. Based on the pollution indices (enrichment factor, geoaccumulation index, pollution index, and pollution load index), lead, arsenic, cadmium, selenium, copper, zinc, and tin from the dry season showed higher contaminations compared to the wet and their concentrations were increased from 2018 to 2020 with seasonal fluctuations. Sediment cadmium and arsenic posed relatively higher and moderate ecological risks. Health risk analysis indicated that lead, cadmium, and inorganic arsenic (estimated) in seafood species pose a possible health threat to the general population. Further, there were possible ecological and health risks for the metal/loids in combination based on the ecological risk index in sediment and the hazard index in seafood, respectively. Source apportionment suggested that anthropogenic activities through uncontrolled shipwrecking operations over the last four decades were the largest polluting dominator, contributing 55-77% of the metal/loid concentrations. Therefore, the data may inform mitigation strategies for emission control at the shipwrecking yards to protect marine ecosystems and their local population., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Exposure to dust particles enriched with arsenic (As) is a significant health threat for populations living in Southeast Asian megacities. The mineralogical composition of dust particles is the key factor that controls the retention and release of As. This study investigated the degree of metal(oid)s pollution (As, Ca, Fe, K, Ga, Rb, Sr, Ti, V, Y, and Zr) in road dust of Dhaka city, Bangladesh. Enrichment factor and geoaccumulation index suggested that the road dust was heavily enriched with As, which triggers a comprehensive investigation of its controlling mechanisms and potential health risks by combining physicochemical and mineralogical information with multivariate analysis and a simulated probabilistic risk estimation model. Alkaline road dust (pH 1:5 ranges from 8.02 to 10.34) in Dhaka city was found to have significant enrichment of As. Dust alkalinity was possibly controlled by the presence of carbonate minerals, such as calcite. Quartz was identified as the dominant mineral phase followed by magnesium carbon arsenide (MgCAs 2 ). Carbonate mineral driven alkaline pH conditions in road dust would potentially trigger the release and mobilization of As to the environment. However, organic complexation can stabilize As on particle surfaces. Monte Carlo simulation-based health risk forecast suggested that the probability of As associated cancer risk has greatly exceeded the threshold value of 1E-4 for adults and children, and children are more vulnerable than adults. According to sensitivity analysis, the concentration of As and exposure duration (ED) posed the most significant impact (>58%) on risk estimation., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A clear understanding of various hydrogeochemical processes is essential for the protection of groundwater quality, which is a prime concern in Bangladesh. The present study deals with the geochemistry of groundwater at various depths to investigate the hydrogeochemical processes controlling the water quality of Meghna floodplain, the sources and mechanisms of arsenic (As) liberation, and the estimation of carcinogenic and non-carcinogenic health risks (using probabilistic and deterministic approaches) to the adults and children of the Comilla district, central-east Bangladesh. The groundwaters were generally of Ca-Mg-HCO 3 type, and water-sediment interaction was the dominant factor in evolving the chemical signatures. The dissolution of carbonates, weathering of silicates, and cation exchange processes governed the major ion chemistry. Dissolved As concentration ranged from 0.002 to 0.36 mg/L and Monte Carlo simulation-based probabilistic estimation of cancer risk suggested that; (1) ~ 83% of the waters exceeded the higher end of the acceptable limit of 1 × 10 -4 ; (2) the probability of additional cases of cancer in every 10,000 adults and children were on average ~9 and ~5, respectively; (3) adults were more susceptible than children; and (4) ingestion was the main pathway of As poisoning and the contribution of dermal contact was negligible (<1%). According to sensitivity analysis, the duration of exposure to As and its concentration in groundwater posed the greatest impact on cancer risk assessment. However, hydrogeochemical investigations on the sources and mobilization mechanisms of As suggested that the reductive dissolution of Fe and Mn oxyhydroxides was the principal process of As release in groundwater. The oxidation of pyrite and competitive exchange of fertilizer-derived phosphate for the sorbed As were not postulated as the plausible explanation for As liberation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Air quality degradation due to high levels of atmospheric particulate matter (PM) of various size fractions and the associated potentially toxic trace elements (PTEs) is a global concern. This article provides a thorough review and analysis of the temporal and spatial distribution of PM and PTEs in Bangladesh, offering a comprehensive assessment with other megacities worldwide based on existing literature. This study provides insights into the sources and transport mechanisms of PM and their link to human health. The level of PM was consistently high in Dhaka (capital of Bangladesh), with occasional higher levels in the surrounding cities. Different functional areas within Bangladesh show varying levels of PM, with total suspended particulates (TSP) being notably prevalent. When compared to megacities worldwide, African and Asian megacities, like India, Pakistan, Nigeria, and Egypt, exhibited higher PM concentrations. The concentration of PM-associated PTEs varies significantly among megacities and PM10 tends to have relatively higher concentrations of PTEs compared to other fractions in Bangladesh. Pb in ambient air was found across most megacities, with a temporal increase in Bangladesh. TSP exhibited the highest relative Pb content, followed by PM10 and PM2.5. Temporal factors, geographic locations, meteorological conditions, and anthropogenic activities contribute to the variation in PM and associated PTEs concentration in Bangladesh and global megacities. Ultimately, this study would aid policymakers in assessing the magnitude of PM pollution in Bangladesh compared to other megacities considering regional factors. [ABSTRACT FROM AUTHOR]

The human exposure to groundwater contamination with toxic elements is a worldwide concern. In this study, multivariate statistics coupled with probabilistic and deterministic risk estimation approaches were applied to 173 groundwater samples of Urmia aquifer (UA) to evaluate human health risks in relation to the consumption of groundwater contaminated with toxic elements. The concentrations of aluminum (Al), barium (Ba), cadmium (Cd), copper (Cu), manganese (Mn), nickel (Ni), and zinc (Zn) were below their corresponding maximum permissible levels as advised by the WHO, USEPA, and Iranian guidelines. However, arsenic (As), lead (Pb), iron (Fe), and selenium (Se) were elevated at some locations. Monte Carlo simulation-based probabilistic risk estimation suggested ingestion as the dominant pathway for water-hosted element exposure. Mean values of hazard index estimated for As exposure from combined ingestion and dermal contact pathways exceeded the safe level of 1.0 for both adults and children, indicated potential non-carcinogenic health risks. The total cancer risk induced by groundwater As exceeded the acceptable limit of 1 × 10–4. Sensitivity analysis highlighted exposure duration, element concentration in water, and average time as the most significant variables causing the probable health risks. Speciation modeling using PHREEQC highlighted the occurrence of As(V) and As(III) in groundwater of the UA. Reductive dissolution of Fe(III) (oxyhydr)oxides and clay minerals was identified as the main controlling mechanism of As mobilization. This communication emphasizes the need for appropriate approaches in mitigating toxic element contamination of water resources in coastal parts of the UA to safeguard public health from carcinogenic and non-carcinogenic risks. [ABSTRACT FROM AUTHOR]

Protection of groundwater quality from various natural and anthropogenic forces is a prime concern in Bangladesh. In this study, we utilized groundwater geochemistry of shallow and deeper aquifers to investigate the hydrogeochemical processes controlling water quality, and the sources and mechanism of Arsenic (As) release to water and associated human health risks in the Faridpur district, Bangladesh. Analysis of hydrochemical facies indicated that groundwaters were Ca–Mg–HCO3 type and that water–rock interactions were the dominant factors controlling their major-ion chemical composition. The dissolution of calcite, dolomite, and silicates, as well as cation exchange processes regulated the major ions chemistry in the groundwater. Dissolved fluoride (F−) concentrations (0.02–0.4 mg/L) were lower than the drinking water standard of 1.5 mg/L set by the World Health Organization (WHO). Arsenic contamination of groundwater is among the biggest health threats in Bangladesh. The measured As concentration (0.01–1.46 mg/L with a mean of 0.12 mg/L) exceeded the maximum permissible limit of Bangladesh and WHO for drinking water. The estimated carcinogenic risk of As exceeded the upper benchmark of 1 × 10–4 for both adult and children, and health threats from shallow groundwater were more severe than the deeper water. The vertical distribution of As resembled Fe and Mn with their higher concentrations in shallow Holocene aquifers and lower in deeper Pleistocene aquifers. Speciation calculation indicated the majority of groundwater samples were oversaturated with respect to siderite, calcite, and dolomite, while undersaturated with respect to rhodochrosite. The saturation state of the minerals along with other processes may exert kinetic control on As, Fe, and Mn distribution in groundwater and lead to their lack of statistically significant correlations. Microbially mediated reductive dissolution of Fe and Mn oxyhydroxides is envisaged as the primary controlling mechanism of As mobilization in Faridpur groundwater. Pyrite oxidation was not postulated as a plausible explanation of As pollution. [ABSTRACT FROM AUTHOR]

The uncontrolled release of harmful metal/loids from mega-scale shipbreaking activities in Bangladesh is a significant concern. This study investigated the impact of shipbreaking activities on soil and crop quality and human health in relation to metal/loid contamination. This work covered an area of 1221 km2 surrounding the shipbreaking yards in Chittagong during the wet and dry seasons between 2019 and 2020. Amongst the sixteen elements measured, the concentrations of Pb, Cd, As, V, Cr, Mn, Cu, Zn, Fe, Co, Ni, and Sn in the soil, rice, and vegetables from the four exposure sites were significantly higher compared to the control site in both seasons. Soil pollution indices indicated moderate to higher contamination levels of Pb, Zn, Cd, As, and Se in 30–50% of soil, supporting their accumulation in food crops. Source apportionment analysis identified uncontrolled shipwrecking operations as the primary anthropogenic activity mainly contributing to metal/loid pollution. Health risk analysis showed inorganic arsenic (estimated), Cd, and Pb in food crops could pose potential health threats to the general population. Spinach leaf and gourd were identified as the highest-risk contributing vegetables in the dry and wet seasons. These findings help to inform management strategies to protect agroecosystems and public health. [Display omitted] • A study of 16 metal/loids in soil and food crops related to shipbreaking impact. • Shipbreaking operations were the largest contributor to the elemental contamination. • Cd, Pb, and As were identified as the significant pollutants and risk contributors. • Contamination of metal/loids varied with seasonal effect. • Shipbreaking waste control is prudent to protect agroecosystem and public health. [ABSTRACT FROM AUTHOR]