Corrigendum to "Enrichment, sources, and distributions of toxic elements in the farming land's topsoil near a heavily industrialized area of central Bangladesh, and associated risks assessment" [Heliyon 9 (4) 2023 e15078].

[This corrects the article DOI: 10.1016/j.heliyon.2023.e15078.].

Using unsupervised machine learning models to drive groundwater chemistry and associated health risks in Indo-Bangla Sundarban region.

Groundwater is an essential resource in the Sundarban regions of India and Bangladesh, but its quality is deteriorating due to anthropogenic impacts. However, the integrated factors affecting groundwater chemistry, source distribution, and health risk are poorly understood along the Indo-Bangla coastal border. The goal of this study is to assess groundwater chemistry, associated driving factors, source contributions, and potential non-carcinogenic health risks (PN-CHR) using unsupervised machine learning models such as a self-organizing map (SOM), positive matrix factorization (PMF), ion ratios, and Monte Carlo simulation. For the Sundarban part of Bangladesh, the SOM clustering approach yielded six clusters, while it yielded five for the Indian Sundarbans. The SOM results showed high correlations among Ca2+, Mg2+, and K+, indicating a common origin. In the Bangladesh Sundarbans, mixed water predominated in all clusters except for cluster 3, whereas in the Indian Sundarbans, Cl--Na+ and mixed water dominated in clusters 1 and 2, and both water types dominated the remaining clusters. Coupling of SOM, PMF, and ionic ratios identified rock weathering as a driving factor for groundwater chemistry. Clusters 1 and 3 were found to be influenced by mineral dissolution and geogenic inputs (overall contribution of 47.7%), while agricultural and industrial effluents dominated clusters 4 and 5 (contribution of 52.7%) in the Bangladesh Sundarbans. Industrial effluents and agricultural activities were associated with clusters 3, 4, and 5 (contributions of 29.5% and 25.4%, respectively) and geogenic sources (contributions of 23 and 22.1% in clusters 1 and 2) in Indian Sundarbans. The probabilistic health risk assessment showed that NO3- poses a higher PN-CHR risk to human health than F- and As, and that potential risk to children is more evident in the Bangladesh Sundarban area than in the Indian Sundarbans. Local authorities must take urgent action to control NO3- emissions in the Indo-Bangla Sundarbans region.

Fractionation of environmental radioactivity in road dust from a megacity: external and internal health risks.

Naturally occurring radioactive materials (NORMs: 232Th, 226Ra, 40K) can reach our respiratory system by breathing of road dust which can cause severe health risks. Targeting the pioneering consideration of health risks from the NORMs in road dust, this work reveals the radioactivity abundances of NORMs in road dust from a megacity (Dhaka) of a developing country (Bangladesh). Bulk chemical compositions of U, Th, and K obtained from neutron activation analysis were converted to the equivalent radioactivities. Radioactivity concentrations of 226Ra, 232Th, and 40K in road dust ranged from 60-106, 110-159, and 488-709 Bq kg-1 with an average of 84.4 ± 13.1, 126 ± 11, and 549 ± 48 Bq kg-1, respectively. Estimated 226Ra, 232Th, and 40K radioactivities were, respectively, 1.7-3.0-, 3.7-5.3-, and 1.2-1.8-folds greater than the affiliated world average values. Mechanistic pathway of NORMs' enrichment and fractionation relative to the major origin (pedosphere) were evaluated concerning the water logging, relative solubility-controlled leaching and translocation, climatic conditions, and aerodynamic fractionations (dry and wet atmospheric depositions). Computation of customary radiological risk indices invokes health risks. Noticing the ingress of NOMR-holding dust into the human respiratory system along with the associated ionizing radiations, the computed radiological indices represent only the least probable health hazards. Nevertheless, in real situations, α-particles from the radioactive decay products of 232Th and 238U can create acute radiation damages of respiratory system. Policymakers should emphasize on limiting the dust particle evolution, and public awareness is required to alleviate the health risks.

Species identification, reproductive biology, and nutritional value of marine shellfish (Meretrix lyrata) in the Bay of Bengal.

Meretrix lyrata which is under the family of Veneridae and under the order of Venerida, is a nutritionally and economically important edible mussel in Bangladesh. However, studies on species identification and nutritional value in M. lyrata are scarce. Therefore, a detailed investigation was conducted on (i) species identification of the common edible mussel through DNA-barcoding and morphometrics, (ii) reproductive features, such as size at sexual maturity, spawning, and peak-spawning seasons under different environmental factors, and (iii) nutritional status through proximate analysis of M. lyrata mussel collected from the Bay of Bengal, Bangladesh. The results indicated that the size at sexual maturity for M. lyrata was 4.2 cm and the spawning seasons were significantly affected by the dissolve oxygen and salinity. The study also demonstrated that the spawning of M. lyrata occurred from January to June and December while peak spawning season was May in the Bay of Bengal. The higher protein and moisture contents with lower fat in M. lyrata indicated that are value-added seafood with higher nutritional values for consumers.

Heavy metals in popularly sold branded cigarettes in Bangladesh and associated health hazards from inhalation exposure.

Tobacco products are widely recognized as a major contributor to death. Cigarette smoke contains several toxic chemicals including heavy metals particulate causing high health risks. However, limited information has been available on the health risks associated with the heavy metals in cigarettes commonly sold in the Bangladeshi market. This study evaluated the concentrations and potential health risks posed by ten concerned heavy metals in ten widely consumed cigarette brands in Bangladesh using an atomic absorption spectrometer. The concentration (mg/kg) ranges of heavy metals Pb, Cd, Cr, As, Co, Ni, Mn, Fe, Cu, and Zn vary between 0.46-1.05, 0.55-1.03, 0.80-1.2, 0.22-0.40, 0.46-0.78, 2.59-3.03, 436.8-762.7, 115.8-184.4, 146.6-217.7, and 34.0-42.7, respectively. We assume that the heavy metals content among cigarette brands is varied due to the differences in the source of tobacco they use for cigarette preparation. The carcinogenic risks posed by heavy metals follow the order of Cr > Co > Cd > As > Ni > Pb, while the non-carcinogenic risks for Cu, Zn, Fe, and Mn were greater than unity (HQ > 1), except for Fe. The existence of toxic heavy metals in cigarette tobacco may thus introduce noticeable non-carcinogenic and carcinogenic health impacts accompanying inhalation exposure. This study provides the first comprehensive report so far on heavy metal concentration and associated health risks in branded cigarettes commonly sold in Bangladesh. Hence, this data and the information provided can serve as a baseline as well as a reference for future research and have potential implications for policy and legislation in Bangladesh.

Occurrences, sources, fate and impacts of plastic on aquatic organisms and human health in global perspectives: What Bangladesh can do in future?

Bangladesh is not an exception to the growing global environmental problem of plastic pollution. Plastics have been deemed a blessing for today's world thanks to their inexpensive production costs, low weight, toughness, and flexibility, but poor biodegradability and massive misuse of plastics are to blame for widespread contamination of the environmental components. Plastic as well as microplastic pollution and its adverse consequences have attracted significant investigative attention all over the world. Plastic pollution is a rising concern in Bangladesh, but scientific studies, data, and related information are very scarce in numerous areas of the plastic pollution problem. The current study examined the effects of plastic and microplastic pollution on the environment and human health, and it examined Bangladesh's existing knowledge of plastic pollution in aquatic ecosystems in light of the rapidly expanding international research in this field. We also made an effort to investigate the current shortcomings in Bangladesh's assessment of plastic pollution. This study proposed several management approaches to the persistent plastic pollution problem by analyzing studies from industrialized and emerging countries. Finally, this work pushed investigators to investigate Bangladesh's plastic contamination thoroughly and develop guidelines and policies to address the issue.

Immobilization of heavy metals in tannery sludge by the formation of tobermorite in subcritical water treatment with rice husk silica.

Tannery sludge, heavy metals (HMs) enriched hazardous solid waste, is produced extensively in many regions of the world. Even though the sludge is hazardous, it can be considered a material resource, if organic matter and HMs in the sludge can be stabilized to minimize its negative environmental impacts. This research aimed to evaluate the efficacy of using subcritical water (SCW) treatment for tannery sludge treatment through immobilization and thus reduction of HMs to mitigate their potential environmental risk and toxicity. HMs in the tannery sludge were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and the average concentration of HMs (mg kg-1) was found in the following decreasing order of Cr (12 950) > Fe (1265) > Cu (76) > Mn (44) > Zn (36) > Pb (14) with very high Cr concentration. The result of toxicity characteristics leaching procedure and sequential extraction procedure tests revealed that the raw tannery sludge leachate contained 11.24 mg L-1 Cr, which classified the raw tannery sludge into a very high-risk category. After SCW treatment, the concentration of Cr in leachate was reduced to 1.6 mg L-1 indicating risk reduction to a low-risk category. The eco-toxicity levels of other HMs also decreased considerably after SCW treatment. X-ray diffractometry (XRD) and scanning electron microscopy (SEM) analysis were employed to identify the effective immobilizing substances formed in the SCW treatment process. The favorable formation of immobilizing orthorhombic tobermorite (Ca5Si6O16(OH)2·4H2O) at 240 °C in the SCW treatment process was confirmed by XRD and SEM analysis. The results confirmed that the formation of 11 Å tobermorite is capable of strongly immobilizing HMs in the SCW treatment process. Further, both orthorhombic 11 Å tobermorite and 9 Å tobermorite were successfully synthesized by SCW treatment on a mixture of tannery sludge including rice husk silica and Ca(OH)2 with water under rather mild conditions. Hence, it can be concluded that SCW treatment of tannery sludge with supplementary silica from rice husk can effectively immobilize the HMs and significantly reduce their environmental risk through tobermorite formation.

Enrichment, sources, and distributions of toxic elements in the farming land's topsoil near a heavily industrialized area of central Bangladesh, and associated risks assessment.

Toxic element accumulation in the surrounding soils of the advanced industry- and agriculture-oriented areas may lead to severe environmental degradation and harmful impact on inhabitants. This work examined the concentration of some concerned toxic elements (Cr, Pb, Cd, Cu, As, and Ni) in the representative topsoil from 10 industrially contaminated sites in central Bangladesh (Narayanganj district) using an Inductively Coupled Plasma Mass Spectrometer concerning the probable ecological and human health risks. The mean concentrations (mg/kg) of the elements were found in the order of Ni (58.1 ± 11.8) > Pb (34.1 ± 14.3) > Cr (32.1 ± 6.77) > Cu (14.5 ± 3.30) > Cd (2.74 ± 1.08) > As (1.49 ± 0.43). The findings pointed out that diversified manmade events enhanced the intensities of elemental contamination through the studied sites. Source analysis showed that Cr, Pb, As, and Cd may originate from industrial wastewater and agricultural activities, whereas Cu and Ni came from natural sources. The geo-accumulation index level for Cd (1.70-3.39) was determined as grade 3 (moderately to strongly polluted), the enrichment factor score for Cd (13.9) fell in the very severe enhanced category (cluster 5), and the highest contamination factor value was found for Cd (15.7). The contamination degree values for all the tested elements signify a moderate to severe contamination grade; conversely, pollution load index levels depicted the nonexistence of elemental pollution. The assessment revealed serious Cd pollution in agricultural soils and moderate to significant potential ecological risk for the rest of the examined toxic elements. Furthermore, hazard index values exceeded the safe exposure levels, indicating that there was potential non-carcinogenic risk in the soils for children and adults. Ingestion exposure had much higher carcinogenic risk values than inhalation and cutaneous exposure, and children are exposed to considerable carcinogenic hazards. Therefore, it is suggested that the harmful practices that expose this farming soil to contaminants should be stopped immediately and effective environment-friendly techniques of waste management and effluent treatment should be employed in the study area.

Pharmaceutical pollution of the world's rivers.

Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world's rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.

Road dust-driven elemental distribution in megacity Dhaka, Bangladesh: environmental, ecological, and human health risks assessment.

Road dust, which reflects ambient air quality, receives various pollutants including toxic metal(oid)s from several natural and/or anthropogenic sources. This manuscript reports a comprehensive evaluation of the levels of seventeen metal(oid)s in road dust of a megacity (Dhaka, Bangladesh). Different evaluation approaches were implemented including statistical analysis and GIS mapping, besides environmental, ecological, and human health risk indices. From 30 sampling sites, representative samples were collected, which were analyzed by neutron activation analysis. The average concentrations (± SD) of Na, Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Zn, As, Rb, Sb, Cs, Ba, and W were 11,738 ± 560 µg g-1, 12,410 ± 1249 µg g-1, 62,127 ± 5937 µg g-1, 8.89 ± 0.47 µg g-1, 5224 ± 1244 µg g-1, 66 ± 8 µg g-1, 66.7 ± 6.9 µg g-1, 547 ± 110 µg g-1, 25,150 ± 1723 µg g-1, 8.39 ± 0.65 µg g-1, 125 ± 17 µg g-1, 3.63 ± 0.56 µg g-1, 87 ± 9 µg g-1, 0.75 ± 0.28 µg g-1, 4.40 ± 0.48 µg g-1, 397 ± 87 µg g-1, and 3.82 ± 1.77 µg g-1, respectively. The distance-based redundancy analysis showed that the northern region was enriched with Na, Mn, Al, Fe, Zn, and Rb, while the southern region was enriched with Fe, Al, Ti, Cr, and Mg. The GIS mapping shows hot spots of Sc, Cr, Zn, and Cs were observed mostly in heavy traffic areas. Significant positive correlations of Fe-Sc, Al-Mg, V-Mg, V-Al, Cs-Rb, Cs-Sc, Rb-Sc, As-Na, and Cs-Rb invoked their inter-dependency and persistence in road dust. Depending on a set of environmental and ecological index-based calculation, the degree of metal(oid) pollution followed the descending order as W > Sb > Zn > Cr > As > Ti > Sc > V, while no pollution was recorded by Mn, Fe, Al, Rb, Cs, Co, and Ba. Importantly, the total hazard index values for adults and children were higher than unity, indicating potential non-carcinogenic health risks from exposure of road dust. Furthermore, the total carcinogenic risks from Cr and As through ingestion and dermal contact exceeded the standard guideline values. The implementation of different evaluation approaches strengthens the findings of metal(oid) source apportionment.

Presence of toxic metals in rice with human health hazards in Tangail district of Bangladesh.

Rice is the staple food of Bangladeshi people and is consumed at least twice a day. Thus, the presence of toxic metals in rice grains has become a major public health concern in Bangladesh. The present research was conducted to investigate the concentrations of toxic metals in rice grains and their possible human health risks in the Tangail district of Bangladesh. Toxic metals were measured by using an inductively coupled plasma mass spectrometer (ICP-MS), and the mean concentrations of toxic metals in rice samples were found in order of Cr > Pb > Ni > As > Cu > Cd. The concentrations of Cr, Pb, As, and Cd in the studied rice grain samples exceeded the FAO/WHO standard values for food samples by 100%, whereas the Ni concentrations by 10%. The principal component analysis (PCA) revealed significant anthropogenic contributions of Cr, Ni, As, and Pb concentrations in rice grains. The metal concentrations in rice grain samples showed strong significant correlations by forming primary clusters with each other. The estimated daily intake (EDI) values of Cr, Ni, As, Cd, and Pb from all samples were higher than the maximum tolerable daily intake (MTDI) allowed. The total targeted hazard quotient (TTHQ) values of Cu, Ni, As, Cd, and Pb also exceeded the threshold value of 1.00, indicating a potential non-carcinogenic risk. The estimated target carcinogenic risk of As was higher than the USEPA threshold level 10-4 (0.0001) indicating increased risk of cancer for adults and children in the study area.

The impact of the COVID-19 pandemic on the mental health of the adult population in Bangladesh: a nationwide cross-sectional study.

The recent COVID-19 pandemic has imposed threats on both physical and mental health since its outbreak. This study aimed to explore the impact of the COVID-19 pandemic on mental health among a representative sample of home-quarantined Bangladeshi adults. A cross-sectional design was used with an online survey completed by a convenience sample recruited via social media. A total of 1,427 respondents were recruited, and their mental health was assessed by the DASS-21 measure. The prevalence of anxiety symptoms and depressive symptoms was 33.7% and 57.9%, respectively, and 59.7% reported mild to extremely severe levels of stress. Perceptions that the pandemic disrupted life events, affected mental health, jobs, the economy and education, predictions of a worsening situation, and uncertainty of the health care system capacities were significantly associated with poor mental health outcomes. Multivariate logistic regressions showed that sociodemographic factors and perceptions of COVID-19 significantly predict mental health outcomes. These findings warrant the consideration of easily accessible low-intensity mental health interventions during and beyond this pandemic.

Receptor model-based source apportionment and ecological risk of metals in sediments of an urban river in Bangladesh.

Metal accumulation (As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) in Korotoa River sediment was studied in order to determine the metal content, distribution, sources, and their possible ecological impacts on the riverine ecosystem. Our study found significant spatial patterns of toxic metal concentration and principal coordinate analysis (PCoA) accounted for 45.2% of spatial variation from upstream to downstream. Metal contents were compared to sediment quality standards and found all studied metal concentrations exceeded the Threshold Effect Level (TEL) whereas Cr and Ni surpassed probable effect levels. All metal concentrations were higher than Average Shale Value (ASV) except Mn and Hg. The positive matrix factorization (PMF) and absolute principal component score-multiple linear regression models (APCS-MLR) were applied to identify promising sources of metals in sediment samples. Both models identified three potential sources i.e. natural source, traffic emission, and industrial pollution, which accounted for 50.32%, 20.16%, and 29.51% in PMF model whereas 43.56%, 29.42%, and 27.02% in APCS-MLR model, respectively. Based on ecological risk assessment, pollution load index (7.74), potential ecological risk (1078.45), Nemerow pollution index (5.50), and multiple probable effect concentrations quality (7.73) showed very high contamination of toxic metal in sediment samples.

Knowledge, attitudes, and preventive practices toward the COVID-19 pandemic: an online survey among Bangladeshi residents.

AIM: The novel coronavirus (SARS-CoV-2) has rapidly infected people worldwide, leading to a massive public reaction. Peoples' knowledge, attitudes, and practices (KAP) toward COVID-19 are the most important for the control and prevention of the infectious disease pandemic. This study aimed to assess the knowledge, attitude, and preventive practices (KAP) toward the COVID-19 among Bangladeshi residents during the lockdown situation. SUBJECTS AND METHODS: An online-based cross-sectional survey was conducted among 1765 Bangladeshi adults through the social media networks of the authors. RESULTS: The respondents were older than 18 years, with an average age of 24.88 years (SD 6.30). Approximately 15% of our participants received online training. The mean knowledge score was 14.49 (SD 1.8, range 0-17), and the overall correct response rate on this knowledge test was 85%. Approximately 67.2% scored well (above the mean 4.5, range 1-5) regarding the practices. To avoid the infection, 96.6% wore masks outside the home, and 98.7% washed their hands with soap when they came back. COVID-19 knowledge score was significantly associated with a lower odds of (OR 0.87, 95% CI 0.79-0.92) negative attitudes. Again, the awareness score was associated with a lower likelihood of (OR 0.94, 95% CI 0.87-0.98) poor practices. CONCLUSION: Online health education programs focusing on young people, housewives, and people with less education may potentially improve the attitudes and practices to control the COVID-19 pandemic in the long term in such a low-resource setting.

Potentially toxic elements in street dust from an urban city of a developing country: ecological and probabilistic health risks assessment.

Anthropogenic activities in and around the urban highways followed by aerodynamic processing generate street dusts, which can cause adverse health effects through different exposure pathways. Hence, considering the high degree of industrialization, concomitant unplanned urbanization, and rapid demographic augmentation, street dust samples from an urban city (Gazipur, Bangladesh) were investigated in terms of potentially toxic elements (using ICP-MS) to evaluate their ecological and health risks. Mean concentrations (± SD) of lead (Pb), copper (Cu), chromium (Cr), cadmium (Cd), zinc (Zn), nickel (Ni), and arsenic (As) in the analyzed air-dried samples were 40.9 ± 13.6, 44.9 ± 15.4, 83.3 ± 19.0, 9.1 ± 5.4, 239.1 ± 34.7, 33.5 ± 10.4, and 2.1 ± 0.8 mg/kg, respectively with heterogeneous distribution which were 0.2 (As) to 82.7 (Cd) times higher than the available internationally recommended limits. Element-specific environmental indices revealed that contamination levels followed the descending order as Cd > Zn > Cu > Pb > Cr > Ni > As, whereas individual ecological risks followed the descending order as Cd > Cu > Pb > Ni > Zn > Cr > As. Sampling site-specific composite indices indicated that sampling sites with high loadings of traffic, population, industrialization, and urbanization were mostly polluted. Multivariate statistical approaches also deduced the similar origins of the studied elements. In terms of the investigated elements, the study site possessed high potential ecological risks, although non-carcinogenic and carcinogenic risks through different pathway's exposures seem insignificant, where children are more vulnerable than adults.

Comprehensive evaluation of chemical properties and toxic metals in the surface water of Louhajang River, Bangladesh.

Louhajang River, Bangladesh, which crosses Tangail as a densely industrialized and urbanized city, supplies water for different purposes. This study reports the levels of pH, electrical conductivity (EC), and some toxic heavy metals in 40 water samples collected during the summer and winter seasons from Louhajang River. The winter season reported higher levels of the examined parameters than the summer season with significant variation (p < 0.05) for all parameters, with the exception of Cd. The metal contents were assessed against local and international standards for drinking, irrigation, and aquatic life purposes where different trends were observed. The heavy metal evaluation index and the ecological risk index reported low to moderate risks. The spatial distribution of metal contents assigned hot spots in some sites along the riverbed. The health risk assessment for three population categories, i.e., adult male, adult female, and children, was examined. Cr and Cd recorded hazard index > 1 in all cases, indicating possible non-cancer risk. The total carcinogenic risk values during both seasons were > 1.0 × 10-6, indicating possible cancer risk. The adopted collection of different approaches (comparison against standard levels of toxicants, statistical analysis, spatial distribution, and health risk assessment) successfully demonstrates a whole picture of the environmental status of Louhajang River, Bangladesh.

Potential toxic metals (PTMs) contamination in agricultural soils and foodstuffs with associated source identification and model uncertainty.

The research aimed to find out physiochemical properties, metal concentration, sources of metals using statistical analyses, and positive matrix factorization (PMF) model using 315 soil and 250 foodstuff samples (25 species) in Jhenidah as well as Kushtia district, Bangladesh. The range of Pb, Cd, As, Cu, Ni and Cr contents (mg/kg) in soils were found to be 0.97-114.72, 0.11-7.51, 1.07-23.38, 0.89-122.91, 0.91-77.32 and 0.7-23.03 mg/kg, respectively, whereas those in foodstuff samples were found to be 0.46-11.48, 0.30-11.54, 0.47-9.21, 0.20-3.59, 0.001-1.76, and 0.27-5.93 mg/kg, respectively. PMF model revealed that Cu (81.4%) in the study area soils were predominantly contributed by vehicular fuel combustion, Cr (84.9%) was primarily of natural origin, Pb (73%) resulted from traffic emissions, Cd (74.3%), and As (63.4%) mainly came from agricultural practices while Ni (70.9%) was dominated as industrial pollution. EF > 1.5 of Cu, As, and Pb suggesting mild contamination; however, soils from all the studied sites revealed moderate potential ecological risk. Cr recorded BCF values of >1 in the majority of the examined crops, suggesting higher uptake of Cr than other metals. Cr, Ni, As, and Pb showed cancer risks from food intake and risk values were greater than the threshold range (10-4), suggesting potential cancer risks.

Investigation of trace metals in riverine waterways of Bangladesh using multivariate analyses: spatial toxicity variation and potential health risk assessment.

Minute quantities of trace metals have delirious effects in the human body causing acute and chronic toxicities. These trace metals have the ability to bind with enzymes and proteins causing an alteration in their activity, and, consequently, their damage. In this study, water samples were collected from five sites in Rupsa River (Bangladesh) during dry and wet seasons aiming to assess the trace metal concentration and the correlated health risk for people living in the area. Six trace metals, namely arsenic (Ar), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and nickel (Ni), were measured for further analyzing their spatial and seasonal variations. The measured trace metal concentrations followed this decreasing order: Cr > Pb > As > Cu > Ni > Cd for the dry season, and Cr > Pb > As > Cu > Ni > Cd for the wet season. Among the trace metals, As, Ni, Cr, and Pb exhibited a statistically significative variation throughout the study period. The PCA analysis accounted for 64.5% and 64.4% total variations of the trace metals in dry and wet seasons, respectively. The Euclidean distance of trace metals in water samples across five sites showed significantly different distribution patterns, which were further confirmed by PERMANOVA. Furthermore, CAP model disclosed that trace metals are source-specific: brickfields and sewage effluents were potential sources for Cd, whereas different industries were potential sources for As, Cr, Cu, Ni, and Pb. Correlation analysis showed that Ni and Cr significantly correlated with pH and electrical conductivity. Correlation among the trace metals unveiled that they depended on each other as for their origin, magnitude, and existence in the riverine waterways. As for the health risk assessment, a non-carcinogenic health hazard due to ingestion during regular activities and dermal contact during fishing activity to all kind of people (adult males, adult females, and children) in the studied area was retrieved based on the hazard index (HI) of trace metals, which was higher than the recommended value (HI > 1). Moreover, also the carcinogenic risks of Ni and As due to regular activities via ingestion and dermal contact pathways were higher than the standard value (CR > 1.0E-04), suggesting the occurrence of cancer risk to humans in the study area.