Papers by Venkatramanan Senapathi
Environmental Science and Pollution Research, Springer Nature, 2025
PLOS one, PLOS, 2025
This study assessed the risks of soil pollution by heavy metals in Chilmari Upazila, northern Ban... more This study assessed the risks of soil pollution by heavy metals in Chilmari Upazila, northern Bangladesh, using the static environmental resilience (Pi) model of soil. Geostatistical modeling and self-organizing maps (SOM) identified pollution areas and spatial patterns, while a positive matrix factorization (PMF) model revealed pollution sources. The results showed that the average concentrations of Cr, Pb and As were well above background levels. Agricultural and industrial soils were mainly contaminated with Cr, Pb and As according to the Nemerow Pollution Index (NPI), Ecological Risk (ER) and Pi Index. Over 70% of the sites were contaminated with Pb and Cr, while co-contamination was particularly high. A one-way ANOVA showed significant correlations between Pb, Cu and Zn levels and human activities. The PMF analysis revealed that industrial effluents, agrochemicals and lithogenic sources were the main contributors to soil contamination with 16%, 41% and 43%, respectively. The SOM analysis revealed three distinct spatial patterns (Pb-Zn, Cr-Cu-Ni and Co-Mn-As), which are consistent with the PMF results. These results emphasize the need for stringent measures to reduce industrial emissions and remediate soil contamination in order to improve soil quality and food security.
Discover Ocean, Springer Nature, 2025
Marine algae, which are often overlooked but extremely versatile, are proving to be a promising s... more Marine algae, which are often overlooked but extremely versatile, are proving to be a promising solution in the midst of environmental challenges. They are used as raw materials in various sectors and also serve as food for humans. The rapid increase in plastics poses an urgent ecological problem that requires immediate attention in the marine ecosystem. This study provides an overview of microplastics (MPs) pollution and its harmful effects on human health. The study also addresses the research gaps and future directions. The data was collected from various databases such as Scopus, Web of Science, Dimension, Pubmed and Pubmed Central. The bibliometric analysis shows that a total of 1020 articles were extracted for the study. Fibers, fragments, foam, films, and microbeads were the most abundant MPs types found in seaweed such as Fucus vesiculosus, Gracilaria lemaneiformis, and Ulva flexuosa. Most of the MP's types were recorded in U. prolifera, Caulerpa prolifera, F. vesiculosus, G. lemaneiformis, Chondrus ocellatus, and Ulva lactuca. These MPs contaminated with MPs can cause oxidative damage, cytotoxicity, neurotoxicity and carcinogenicity in consumers. Most studies on MPs contamination of algae were conducted in 2020, 2021 and 2022. This suggests that since algae are consumed worldwide, additional field and laboratory studies are needed to determine the true situation. The results also suggest that further research is needed on the effects of MPs contaminated with MPs on human health. Further global studies are needed, as well as continuous monitoring of MPs levels in edible algae. Public awareness is crucial to minimize the impact of plastic on the oceans, which requires innovative technologies, consumer choices and environmental responsibility. Interdisciplinary collaboration is key for sustainable coexistence with the marine environment.
Environmental Monitoring and Assessment, Springer Nature, 2025
Groundwater is often used directly by the public in several river basins of India. Hence, this st... more Groundwater is often used directly by the public in several river basins of India. Hence, this study was carried out with the objective of assessing the quality of groundwater in the Amaravathi basin, India, using a multiple indices approach. Groundwater quality data from 96 monitoring wells were obtained from the Central Groundwater Board and used in this study. Drinking water quality index (DWQI) and irrigation water quality index (IWQI) were calculated to assess the water suitability for consumption, irrigation, and farming. High levels of fluoride and nitrate have a detrimental impact on health and were evaluated using USEPA methods by calculating the chronic daily intake and hazards quotient. Findings revealed that 42% of samples did not meet the DWQI standards due to high salinity, hardness, nitrate, and fluoride levels. Health risk assessment (HRA) of hazard quotients of nitrate are 81%, 61%, and 39% of samples, while those of fluoride are 85%, 68%, and 18% of samples for infants, children, and adults, respectively are unfit. High salinity rendered 35% of the sample unsuitable for irrigation, though most remained suitable for livestock. Spatial analysis revealed declining groundwater quality from the center to the east of the basin. This mapping study identified areas where the groundwater quality is inappropriate for the intended purpose and alternate water sources should be made viable.
Bulletin Environmental Contamination and Toxicology, Springer Nature, 2025
such as marine, fluvial and lacustrine settings. Separating MP particles from organic matter is a... more such as marine, fluvial and lacustrine settings. Separating MP particles from organic matter is a particularly challenging process. However, in recent years, researchers have increasingly focused on MPs in wastewater (Tagg et al. 2020; Hidalgo-Ruz et al. 2012). Despite the difficulties, investigating the fate of MPs in wastewater is crucial (Sun et al. 2019). Understanding the load of MPs in wastewater treatment plants and estimating the volume of MPs released into the marine environment via untreated wastewater are significant to derive proper controlling measures (Tagg et al. 2020; Lares et al. 2018). There were 700 marine species including fishes, penguins, sea turtles and crustaceans reported to be adversely affected by the introduction of MPs (Gholizadeh et al. 2023; Issac and Kandasubramanian 2021; Marn et al. 2020). Hence, it is important to study the accumulation of MPs in the marine environment from all sources and origins. Despite extensive research on MPs in various environmental compartments, there is a notable gap in comprehensive data regarding their occurrence and concentrations in wastewater (Bläsing and Amelung 2018; Kawecki and Nowack 2019). Wastewater is categorized into primary and secondary sewage sludge, each differing significantly in composition
Journal of Contaminated Hydrology, 2025
Investigating the potential of novel data mining algorithms (DMAs) for modeling groundwater quali... more Investigating the potential of novel data mining algorithms (DMAs) for modeling groundwater quality in coastal areas is an important requirement for groundwater resource management, especially in the coastal region of Bangladesh where groundwater is highly contaminated. In this work, the applicability of DMA, including Gaussian Process Regression (GPR), Bayesian Ridge Regression (BRR) and Artificial Neural Network (ANN), for predicting groundwater quality in coastal areas was investigated. The optuna-based optimized hyperparameter is proposed to improve the accuracy of the models, including optuna-GPR and optuna-BRR as benchmark models. Combined cross-validation (CV) and bootstrapping (B) methods were used to build six predictive models. The entropy-based coastal groundwater quality index (ECWQI) was converted into a normalized index (ECWQIn), which was divided into five classes from very poor to excellent. The self-organizing map (SOM), spatial autocorrelation and fuzzy logic model were used to identify spatial groundwater quality patterns based on 12 physicochemical variables collected from 67 groundwater wells. The SOM analysis identified four distinct spatial patterns, including EC-TDS-Cl−, Mg-pH, Ca2+-K+ -NO₃−, and HCO₃− -SO₄2−-Na+-F−. The results showed that both the ANN (CV) and ANN (B) models performed better than other optuna-based models during the test phase (RMSE = 0.041, MAE = 0.026, R2 = 0.971, RAE = 0.15 = 21 and CC = 0.986) and (RMSE = 0.041, MAE = 0.025, R2 = 0.969, RAE = 0.119 and CC = 0.975), respectively. SO42−, Cl− and F− played an important role in the prediction accuracy. F- and SO42− showed higher spatial autocorrelation, which affected groundwater quality degradation. In addition, the ANN (CV) and ANN (B) models showed a Gaussian distribution of model errors (small standard error, <1 %), indicating the stability of the model. These results indicate the efficiency of the ANN model in predicting groundwater quality in coastal areas, which would help regional water managers in real-time monitoring and management of sustainable groundwater resources.
Science of The Total Environment, Elsevier, 2025
including those for text and data mining, AI training, and similar technologies. Coastal region B... more including those for text and data mining, AI training, and similar technologies. Coastal region Bangladesh HCO₃-SO₄ 2-PO 4 3-F-. Four data-driven algorithms, including CatBoost, Gradient Boosting Machine (GBM), Long Short-Term Memory (LSTM), and Support Vector Regression (SVR) were used to predict phosphate concentration in GW using 380 samples and 15 prediction parameters. Forecasting accuracy was evaluated using RMSE, R 2 , RAE, CC, and MAE. Phosphate dissolution and saltwater intrusion, along with phosphorus fertilizers, increase PO 4 3-content in GW. Using input parameters selected by multicollinearity and SOM, the CatBoost model showed exceptional performance in both training (RMSE = 0.002, MAE = 0.001, R 2 = 0.999, RAE = 0.057, CC = 1.00) and testing (RMSE = 0.001, MAE = 0.002, R 2 = 0.989, RAE = 0.057, CC = 0.998). Na + , K + , and Mg 2+ significantly influenced prediction accuracy. The uncertainty study revealed a low standard error for the Cat-Boost model, indicating robustness and consistency. Semi-variogram models confirmed that the most influential attributes showed weak dependence, suggesting that agricultural runoff increases the heterogeneity of PO 4 3distribution in GW. These findings are crucial for developing conservation and strategic plans for sustainable utilization of coastal GW resources.
International Journal of Sediment Research, Elsevier, 2025
In the context of transboundary rivers, which constitute intricate fluvial ecosystems, the persis... more In the context of transboundary rivers, which constitute intricate fluvial ecosystems, the persistent threat of heavy metals (HMs) contamination poses significant risks to ecosystem health. In this study, ecotoxicological hazards, governing factors, and the distribution of nine HMs (uranium (U), lead (Pb), cadmium (Cd), nickel (Ni), chromium (Cr), manganese (Mn), iron (Fe), zinc (Zn), and copper (Cu)), as well as sediment characteristics (sand, silt, clay, organic matter, and pH) are assessed within the sediment. The current investigation encompasses the analysis of twenty-seven sediment samples, utilizing inductively coupled plasma mass spectrometry, in the transboundary river basin of Bangladesh, specifically the Teesta River. Notably, the findings underscore the predominance of Cd as a contaminant, responsible for 51.85%, 81.84%, and 100% of the geo-accumulation index, contamination factor, and enrichment factor, respectively. The Teesta River emerges as moderately to highly polluted, with cumulative probabilities of 7.4%, 85.2%, and 7.4% denoting “medium”, “high”, and “priority” pollution levels, respectively. Regions in the upstream and downstream middle sections of the study area exhibit relatively higher pollution levels, particularly in proximity to Kaunia Upazila in the Rangpur district. Ecologically, the potential risk index indicates a low likelihood of ecological impacts at 77.8%, alongside a moderate risk observation of 22.2%. The current results attribute the distribution of these HMs to the pH and organic matter content within the sediment, serving as pivotal factors. To unravel the origins of the HMs, the positive matrix factorization (PMF) model successfully identifies four contributing factors, primarily from geogenic sources. Validation of the PMF model through Spearmen correlation and principal component analysis (PCA) reveals a consistent pattern, affirming its efficacy in this analysis. Within the region, HM sources are identified as originating from anthropogenic activities such as irrigation, industrial discharges, and domestic effluent, in addition to substantial inputs from geogenic sources. Recognizing the transboundary nature of metal pollution, the current study underscores the imperative for continuous and vigilant monitoring, coupled with the implementation of robust management practices. The interplay of both anthropogenic and geogenic factors necessitates a comprehensive approach to effectively and sustainably combat HM contamination.
Regional Studies in Marine Science, Elsevier, 2024
Microplastics (MPs) have garnered global attention as emerging pollutants in aquatic and terrestr... more Microplastics (MPs) have garnered global attention as emerging pollutants in aquatic and terrestrial ecosystems. Despite their significance, studies on MP pollution have overlooked a biodiverse island ecosystem in the northeast Bay of Bengal. Hence, the current study is a pioneering effort to delve into this issue with the island. This research embodies the first comprehensive report exploring the presence of MP pollution in sediment and surface water and their influencing factors along Sandwip island in the northeast Bay of Bengal. The average MP concentration was 305 ± 37.16 (items/kg) in sediment and 106.14 ± 22.57 (items/m 3) in surface water. Fragments emerged as the predominant type in sediment (78.77%) and surface water (54.64%) samples. Fourier Transform Infrared Spectroscopy identified three plastic polymers, the most abundant being polyethylene (56%) and polypropylene (41%). Anthropogenic activities, particularly fishing practices, improper waste disposal, and inadequate waste management strategies, were pinpointed as potential sources of MP contamination on the island. MP concentrations in water and sediment correlated positively with pH and organic matter (p < 0.000), indicating important factors influencing MP distribution. The spatial distribution and hotspots of MPs followed significant human routes. By shedding light on the extent of MPs' presence and their potential sources, this study contributes essential insights that can inform effective environmental management strategies for the island's future well-being.
Groundwater for Sustainable Development, Elsevier, 2024
This study evaluates the risks associated with geogenic and anthropogenic contaminants in the Aza... more This study evaluates the risks associated with geogenic and anthropogenic contaminants in the Azarshahr aquifer situated in the Lake Urmia watershed in NW Iran, an area critically affected by both natural mineral deposits and intensive agricultural activities. This region, characterized by its significant geological diversity and extensive
use of pesticides and fertilizers, presents a unique opportunity to study the interaction between natural and human-induced groundwater contamination. Employing the Origin-Source-Pathway-Receptors-Consequence
(OSPRC) framework, the research focuses on the linkage between these contaminants and waterborne diseases, particularly examining the less-studied “Receptor” and “Consequence” components using the Groundwater
Quality Index (GQI) and health risk indices. Our approach integrates vulnerability assessments through the
DRASTIC and SPECTR methods, enhanced by Sugeno fuzzy logic, to produce a detailed risk map highlighting two
critical zones: Risk Cell 1, impacted predominantly by agricultural contaminants including nitrate and chlorpyrifos, and Risk Cell 2, affected by geogenic contaminants such as arsenic, lead, nickel, and chromium. This
comprehensive analysis not only maps out the source and migration pathways of these contaminants but also
evaluates their impact on human health. The findings underscore a strong correlation between identified risks
and health impacts, emphasizing the pressing need for targeted health interventions and improved management
of water resources in the region. By advancing the application of the OSPRC framework, this research fills a vital
gap in our understanding of aquifer contamination dynamics and sets a new standard for future groundwater risk
assessments.
Acta Tropica, Elsevier, 2024
Climate change is a significant risk multiplier and profoundly influences the transmission dynami... more Climate change is a significant risk multiplier and profoundly influences the transmission dynamics, geographical
distribution, and resurgence of vector-borne diseases (VBDs). Bangladesh has a noticeable rise in VBDs attributed
to climate change. Despite the severity of this issue, the interconnections between climate change and VBDs in
Bangladesh have yet to be thoroughly explored. To address this research gap, our review meticulously examined
existing literature on the relationship between climate change and VBDs in Bangladesh. Using the Preferred
Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach, we identified 3849 records from
SCOPUS, Web of Science, and Google Scholar databases. Ultimately, 22 research articles meeting specific criteria
were included. We identified that the literature on the subject matter of this study is non-contemporaneous, with
68% of studies investing datasets before 2014, despite studies on climate change and dengue nexus having
increased recently. We pinpointed Dhaka and Chittagong Hill Tracts as the dengue and malaria research hotspots, respectively. We highlighted that the 2023 dengue outbreak illustrates a possible shift in dengue-endemic
areas in Bangladesh. Moreover, dengue cases surged by 317% in 2023 compared to 2019 records, with a corresponding 607% increase in mortality compared to 2022. A weak connection was observed between dengue
incidents and climate drivers, including the El Nino ˜ Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD).
However, no compelling evidence supported an association between malaria cases, and Sea Surface Temperature
(SST) in the Bay of Bengal, along with the NINO3 phenomenon. We observed minimal microclimatic and nonclimatic data inclusion in selected studies. Our review holds implications for policymakers, urging the prioritization of mitigation measures such as year-round surveillance and early warning systems. Ultimately, it calls for
resource allocation to empower researchers in advancing the understanding of VBD dynamics amidst changing
climates.
Frontiers in Earth Sciences, Frontiers, 2024
Editorial on the Research Topic
Sichuan-Tibet traffic corridor: fundamental geological investigat... more Editorial on the Research Topic
Sichuan-Tibet traffic corridor: fundamental geological investigations and
resource endowment-volume II
Discover Oceans, Springer Nature, 2024
Seaweeds are grown for their use in food and other sectors, however heavy metals (HMs) contaminat... more Seaweeds are grown for their use in food and other sectors, however heavy metals (HMs) contamination raises serious issues for the environment and public health. This study focuses on seaweed samples (Hypnea musciformes and Gracilaria lemaneiformis) collected from the Rezu Khal seaweed culture site, Cox's Bazar coast, Bangladesh. HMs and minerals were determined using Atomic Absorption Spectrophotometry (AAS). Among the elements examined, H. musciformes displayed the highest mean concentrations of minerals and HMs, including Magnesium (Mg) (8663.00 ± 2302.06 mg/kg), Copper (Cu) (10.59 ± 1.61 mg/kg), Iron (Fe) (7566.29 ± 2842.47 mg/kg), Manganese (Mn) (9.93 ± 2.88 mg/kg), Zinc (Zn) (29.54 ± 7.51 mg/kg), and Nickel (Ni) (11.77 ± 2.63 mg/kg). Conversely, G. lemaneiformis exhibited the highest levels of Calcium (Ca) (798.14 ± 143.40 mg/kg), Lead (Pb) (3.91 ± 1.74 mg/kg), and Chromium (Cr) (0.59 ± 0.30 mg/kg). Specifically, Mg was prominently abundant in H. musciformes, while Cawas more prevalent in G. lemaneiformis. Both seaweed types contained Pb and Cr. None of the elements was significantly different between the species (p < 0.05). The consumers are not exposed to any carcinogenic or non-carcinogenic risks related to these concentrations, according to the evaluation of carcinogenic and non-carcinogenic risks.
Regional Studies in Marine Science, Elsevier, 2024
The global concern over the pollution-induced by microplastics (MPs) has intensified due to its a... more The global concern over the pollution-induced by microplastics (MPs) has intensified due to its adverse effects on the environment, particularly in terrestrial ecosystems, where it poses potential threats to soil quality and resident species. However, there is a noticeable research gap regarding soil MPs in dumping sites, specifically within the Rohingya Refugee Camp (RRC), the world's largest humanitarian crisis located in Bangladesh. The main objective of this study is to assess soil MPs' abundance, spatial distribution, and inherent risks in the RRC. The investigation involved extracting MPs from ten soil sampling sites in Kutupalong RRC, home to Rohingya refugees who sought refuge in Bangladesh following the 2017 ethnic atrocities in Northern Rakhine State, Myanmar. Stereomicroscopy and Fourier transform infrared spectroscopy were employed for identification purposes. The concentration of MPs in the study area varied from 67 to 126 (items/kg) (dry weight), with a mean concentration of 103.80 ± 20.671 (items/kg). MPs with sizes <0.5 mm constituted the majority at 83 %, with fragments (68 %) being the prevailing shape, and transparent (63 %) as the most abundant color. Predominant polymers included polyethylene (53 %) and polypropylene (46 %). Negative correlations were observed between MP abundance and pH and moisture content (p<0.05), while a positive correlation was found between MP abundance and organic matter. PCA results suggested that human-induced inappropriate waste and air deposition are the primary sources of soil MP pollution. Contamination factor values suggested moderate pollution with MPs in the study area. According to the geo-accumulation index (Igeo), the area was classified as pollution grade II, signifying 'uncontaminated to moderately contaminated.' However, pollutant load index and potential ecological risk index indicated Hazard Level-I and Pollution Grade-I, respectively. This study illuminates the contamination scenario with MPs, underscoring concerns for eco-environmental safety and providing crucial data for future investigations into MPs in terrestrial dumping habitats.
Environmental Science and Pollution Research, Springer, 2024
Despite sporadic and irregular studies on heavy metal(loid)s health risks in water, fish, and soi... more Despite sporadic and irregular studies on heavy metal(loid)s health risks in water, fish, and soil in the coastal areas of the Bay of Bengal, no chemometric approaches have been applied to assess the human health risks comprehensively. This review aims to employ chemometric analysis to evaluate the long-term spatiotemporal health risks of metal(loid)s e.g., Fe, Mn, Zn, Cd, As, Cr, Pb, Cu, and Ni in coastal water, fish, and soils from 2003 to 2023. Across coastal parts, studies on metal(loid)s were distributed with 40% in the southeast, 28% in the south-central, and 32% in the southwest regions. The southeastern area exhibited the highest contamination levels, primarily due to elevated Zn content (156.8 to 147.2 mg/L for Mn in water, 15.3 to 13.2 mg/kg for Cu in fish, and 50.6 to 46.4 mg/kg for Ni in soil), except for a few sites in the south-central region. Health risks associated with the ingestion of Fe, As, and Cd (water), Ni, Cr, and Pb (fish), and Cd, Cr, and Pb (soil) were identified, with non-carcinogenic risks existing exclusively through this route. Moreover, As, Cr, and Ni pose cancer risks for adults and children via ingestion in the southeastern region. Overall non-carcinogenic risks emphasized a significantly higher risk for children compared to adults, with six, two-, and six-times higher health risks through ingestion of water, fish, and soils along the southeastern coast. The study offers innovative sustainable management strategies and remediation policies aimed at reducing metal(loid)s contamination in various environmental media along coastal Bangladesh.
Journal of Hydrology: Regional Studies, Elsevier, 2024
The investigated mineral groundwater has outstanding water quality and slightly alkaline nature. ... more The investigated mineral groundwater has outstanding water quality and slightly alkaline nature. It is with fresh hydrochemical facies of HCO3-Na⋅Ca type with total dissolved solids (TDS) in the range o 384–964 mg/L, and featured by notably rich strontium with the concentrations o 0.67–0.81 mg/L, ar exceeding the recommended mineral water minimum threshold o 0.20 mg/L. The mineral groundwater is originated from the glacier meltwater of mountainous area with elevation over 4500 m. It subsequently inltrates into the bedrock and move within the groundwater system with a residence time of approximately 52 years. Its hydrochemical constituents are naturally governed by water-rock interactions of silicates dissolution, cation exchange, and celestite and strontianite dissolution. A conceptual model is proposed to outline the ormation pattern o glacial mineral water in alpine region on Tibetan Plateau. Findings o this study can ll the study gap regarding glacial mineral water on Tibetan Plateau, and urther contribute to the uture study and development o natural glacial mineral water in alpine regions worldwide.
Ocean and Coastal Management, Elsevier, 2024
This research paper addresses the urgent environmental concern of microplastic (MP) emissions, fo... more This research paper addresses the urgent environmental concern of microplastic (MP) emissions, focusing on the behavioral attitudes and perceptions of the general populace in Shyamnagar Upazila, Bangladesh. Against the backdrop of escalating MP pollution globally, this study investigates the level of awareness and the factors influencing public engagement in mitigating MP prevalence. Leveraging survey data from 350 respondents, the
ordered logistic regression (OLR) and boosted regression tree (BRT) models are employed for comprehensive
data analysis. The findings expose a concerning lack of awareness about MPs, as only 12% of respondents possessed prior knowledge, and a notable 63% remained uninformed about MP pollution. The OLR model reveals
a positive correlation between heightened awareness of MPs and an increased willingness to take action. Gender differences become evident, with women exhibiting greater willingness than men to mitigate MP emissions, and environmental practitioners displaying heightened motivation. The BRT model underscores construction materials and industrial pollution as the primary influential factors amplifying MP pollution. These insights not only illuminate the existing scenario but also provide a basis for fostering favorable behavioral attitudes and perceptions to mitigate the prevalence of MPs within the coastal milieu.
Environmental Research, Elsevier, 2024
Understanding the major factors influencing groundwater chemistry and its evolution in irrigation... more Understanding the major factors influencing groundwater chemistry and its evolution in irrigation areas is crucial for efficient irrigation management. Major ions and isotopes (δD-H 2 O together with δ 18 O-H 2 O) were used to identify the natural and anthropogenic factors contributing to groundwater salinization in the shallow aquifer of the Wadi Guenniche Plain (WGP) in the Mediterranean region of Tunisia. A comprehensive geochemical investigation of groundwater was conducted during both the low irrigation season (L-IR) and the high irrigation season (H-IR). The results show that the variation range and average concentrations of almost all the ions in both the L-IR and H-IR seasons are high. The groundwater in both seasons is characterized by high electrical conductivity and CaMgCl/SO 4 and NaCl types. The dissolution of halite and gypsum, the precipitation of calcite and dolomite, and Na-Ca exchange are the main chemical reactions in the geochemical evolution of groundwater in the Wadi Guenniche Shallow Aquifer (WGSA). Stable isotopes of hydrogen and oxygen (δ 18 O-H 2 O and δD-H 2 O) indicate that groundwater in WGSA originated from local precipitation. In the H-IR season, the δ 18 O-H 2 O and δD-H 2 O values indicate that the groundwater experienced noticeable evaporation. The enriched isotopic signatures reveal that the WGSA's groundwater was influenced by irrigation return flow and seawater intrusion. The proportions of mixing with seawater were found to vary between 0.12% and 5.95%, and between 0.13% and 8.42% during the L-IR and H-IR seasons, respectively. Irrigation return flow and the associated evaporation increase the dissolved solids content in groundwater during the irrigation season. The long-term human activities (fertilization, irrigation, and septic waste infiltration) are the main drives of the high nitrate-N concentrations in groundwater. In coastal irrigation areas suffering from water scarcity, these results can help planners and policy makers understand the complexities of groundwater salinization to enable more sustainable management and development.
Environmental Research, Elsevier, 2024
While global attention has been primarily focused on the occurrence and persistence of microplast... more While global attention has been primarily focused on the occurrence and persistence of microplastics (MP) in urban lakes, relatively little attention has been paid to the problem of MP pollution in rural recreational lakes. This pioneering study aims to shed light on MP size, composition, abundance, spatial distribution, and contributing factors in a rural recreational lake, 'Nikli Lake' in Kishoreganj, Bangladesh. Using density separation, MPs were extracted from 30 water and 30 sediment samples taken from ten different locations in the lake. Subsequent characterization was carried out using a combination of techniques, including a stereomicroscope, Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FE-SEM). The results showed a significant prevalence of MPs in all samples, with an average amount of 109.667 ± 10.892 pieces/kg 3 (dw) in the sediment and 98.167 ± 12.849 pieces/m 3 in the water. Small MPs (<0.5 mm), fragments and transparent colored particles formed the majority, accounting for 80.2%, 64.5% and 55.3% in water and 78.9%, 66.4% and 64.3% in sediment, respectively. In line with global trends, polypropylene (PP) (53%) and polyethylene (PE) (43%) emerged as the predominant polymers within the MPs. MP contents in water and sediment showed positive correlations with outflow, while they correlated negatively with inflow and lake depth (p > 0.05). Local activities such as the discharge of domestic sewage, fishing waste and agricultural runoff significantly influence the distribution of polypropylene. Assessment of pollution factor, pollution risk index and pollution load index values at the sampling sites confirmed the presence of MPs, with values above 1. This study is a baseline database that provides a comprehensive understanding of MP pollution in the freshwater ecosystem of Bangladesh, particularly in a rural recreational lake. A crucial next step is to explore ecotoxicological mechanisms, legislative measures and future research challenges triggered by MP pollution.
Chemosphere, Elsevier, 2024
Groundwater is an essential resource in the Sundarban regions of India and Bangladesh, but its qu... more 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 noncarcinogenic 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.
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Papers by Venkatramanan Senapathi
use of pesticides and fertilizers, presents a unique opportunity to study the interaction between natural and human-induced groundwater contamination. Employing the Origin-Source-Pathway-Receptors-Consequence
(OSPRC) framework, the research focuses on the linkage between these contaminants and waterborne diseases, particularly examining the less-studied “Receptor” and “Consequence” components using the Groundwater
Quality Index (GQI) and health risk indices. Our approach integrates vulnerability assessments through the
DRASTIC and SPECTR methods, enhanced by Sugeno fuzzy logic, to produce a detailed risk map highlighting two
critical zones: Risk Cell 1, impacted predominantly by agricultural contaminants including nitrate and chlorpyrifos, and Risk Cell 2, affected by geogenic contaminants such as arsenic, lead, nickel, and chromium. This
comprehensive analysis not only maps out the source and migration pathways of these contaminants but also
evaluates their impact on human health. The findings underscore a strong correlation between identified risks
and health impacts, emphasizing the pressing need for targeted health interventions and improved management
of water resources in the region. By advancing the application of the OSPRC framework, this research fills a vital
gap in our understanding of aquifer contamination dynamics and sets a new standard for future groundwater risk
assessments.
distribution, and resurgence of vector-borne diseases (VBDs). Bangladesh has a noticeable rise in VBDs attributed
to climate change. Despite the severity of this issue, the interconnections between climate change and VBDs in
Bangladesh have yet to be thoroughly explored. To address this research gap, our review meticulously examined
existing literature on the relationship between climate change and VBDs in Bangladesh. Using the Preferred
Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach, we identified 3849 records from
SCOPUS, Web of Science, and Google Scholar databases. Ultimately, 22 research articles meeting specific criteria
were included. We identified that the literature on the subject matter of this study is non-contemporaneous, with
68% of studies investing datasets before 2014, despite studies on climate change and dengue nexus having
increased recently. We pinpointed Dhaka and Chittagong Hill Tracts as the dengue and malaria research hotspots, respectively. We highlighted that the 2023 dengue outbreak illustrates a possible shift in dengue-endemic
areas in Bangladesh. Moreover, dengue cases surged by 317% in 2023 compared to 2019 records, with a corresponding 607% increase in mortality compared to 2022. A weak connection was observed between dengue
incidents and climate drivers, including the El Nino ˜ Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD).
However, no compelling evidence supported an association between malaria cases, and Sea Surface Temperature
(SST) in the Bay of Bengal, along with the NINO3 phenomenon. We observed minimal microclimatic and nonclimatic data inclusion in selected studies. Our review holds implications for policymakers, urging the prioritization of mitigation measures such as year-round surveillance and early warning systems. Ultimately, it calls for
resource allocation to empower researchers in advancing the understanding of VBD dynamics amidst changing
climates.
Sichuan-Tibet traffic corridor: fundamental geological investigations and
resource endowment-volume II
ordered logistic regression (OLR) and boosted regression tree (BRT) models are employed for comprehensive
data analysis. The findings expose a concerning lack of awareness about MPs, as only 12% of respondents possessed prior knowledge, and a notable 63% remained uninformed about MP pollution. The OLR model reveals
a positive correlation between heightened awareness of MPs and an increased willingness to take action. Gender differences become evident, with women exhibiting greater willingness than men to mitigate MP emissions, and environmental practitioners displaying heightened motivation. The BRT model underscores construction materials and industrial pollution as the primary influential factors amplifying MP pollution. These insights not only illuminate the existing scenario but also provide a basis for fostering favorable behavioral attitudes and perceptions to mitigate the prevalence of MPs within the coastal milieu.
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 noncarcinogenic 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.