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1.
Environ Res ; 203: 111741, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34310967

RESUMO

The present study traces the geochemical occurrence of arsenic and heavy metals along the active oxbow formations of river Ganga in MGP. A total of 31 groundwater samples were collected, specifically in close proximity to the river profile section, to understand the high spatial enrichment pattern of arsenic. The bivariate plots reveal strong influence of silicate weathering and anthropogenic leaching of fertilizers occurring concurrently with pyrite oxidation, leading to high arsenic vulnerability. The bicarbonate enrichment plays a major role in the replacement of adsorbed arsenic while most of the carbonate minerals remain in a state of oversaturation, causing their ultimate precipitation. The steep changes in river directional profile as evident through the high bulk density of the soil (1587 kg/m3) near the oxbow formations of the river has caused high sediment deposition which is coherent with the spatial distribution of soil organic carbon stock (8-33 tons/hectare). Further, high concentration of arsenic (~100 ppb) traces the high availability of the clay content (18-40 %) and moderate iron concentration of the soil confirming the role of river led recharge in promoting oxidizing conditions. Low cation exchange capacity (9-52 mmol. c.kg-1), indicative of illite as the dominant clay mineral, further supports our concern for groundwater vulnerability in terms of enhanced cation retention in the soil. Our study is a pioneering work in understanding arsenic spatial vulnerability under fluvial forcing through developing indicators which trace the arsenic mobilizing chemistry in a more coherent and direct ways.

2.
Sci Total Environ ; : 151461, 2021 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-34748831

RESUMO

The Ganga-Brahmaputra floodplains constitute a complex system that is vulnerable to arsenic recycling owing to its geomorphic sensitivity, aquifer profiles, high meandering scars and extreme sediment deposition, along with extreme monsoonal disturbances; and are subjected to significant alterations in arsenic recycling. We have put an effort to delineate the similarities and dissimilarities pertaining to the arsenic prevalence, origin and mobilization in the two hotspots, namely the Mid-Gangetic Floodplains (MGFP) and the Brahmaputra Floodplains (BFP). Pertaining to this, we collected 384 representative water samples for hydrogeochemical investigations, multivariate analyses, and saturation status based predictive modelling, with BFP having a maximum concentration of arsenic (As) reaching to almost 97.9 µgL-1 and MGFP having a maximum concentration of 50.1 µgL-1. Seasonality impelled changes and conforming riverine recharges are leading major ionic differentiations in both the floodplains across seasons. Meandering and aquifer dynamics control As prevalence in the MGFP and BFP, respectively. Non-interdependent HCO3- recharge mediated As-recycling was found in the BFP. Carbonate weathering is dominant in the MGFP, while both carbonate and silicate weathering take precedence in the BFP. Multivariate analysis hints at fertilizer influence on As mobilization in the MGFP. Reductive hydrolysis of Fe-OOH mediated As-release is more prominent in the BFP. Seasonal arsenic fluctuations are going to have more climatic dependency in near future owing to the increasing erratic rains, pumping and recharge events. Erratic precipitation will provoke immediate response in both floodplains in terms of As mobilization which urgently needs attention to counter increasing arsenic vulnerability.

3.
Int J Hyg Environ Health ; 237: 113836, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34481208

RESUMO

Our surrounding environment has been influenced by the COVID-19 pandemic situation. The second wave of COVID-19 in India has proven to be more devastating and aggressive than the first wave of the pandemic, which led to recognizing India as one of the world's topmost worst-hit nations considering >4000 fatalities reported in a single day in May 2021. Such "resurgence and acceleration" of COVID-19 transmission has been fuelled by the MahaKumbh festival and political mass gathering (elections rallies) events, where the COVID-19 protocols have been ignored by millions of pilgrims/followers. The present review discusses only the consequences of this year's MahaKumbh festivals, the largest religious mass gathering on earth, which was held during the COVID-19 pandemic in India, and its impact on both the spread of SARS-CoV-2 among participants and their families and its influence on the quality of the river Ganga. This article tries to give readers outside of India an overview of how much impact of any such single large gathering of any relgion in any part of the world can drive coronavirus infections and effectively commence the second/third wave outbreak with this case study. Furthermore, the religious large scale celebration are widely accepted through out the world that have played a significant role in the spread of the pandemic into remote villages and towns all over the subcontinent/world, thus affecting many areas with insufficient healthcare facilities that have been relatively spared. This review also highlights the potential risk of transmission from infected humans into the aquatic environment of the river Ganga. Besides the obvious relevance of SARS-CoV-2, a large variety of other water-related disease vectors (bacteria, viruses, and protozoa) stemming from visitors to the religious congregation were introduced into the upstream regions of the Ganga river. Their sheer number is assumed to have had a severe influence on its delicate ecosystem, including endangered mammals such as the river Dolphins. The detailed epidemiological and clinical study on transmission routes of SARS-CoV-2 is the need of the hour to understand the pathogenesis of RNA virus infection and prevent the massive spreading of such infectious respiratory diseases. An interdisciplinary approach, rooted in evidence-based efficient learning, contextual strategies, and a streamlined unified approach should be adopted to help in the development of a proactive prevention model during future MahaKumbh festival (and similar religious gatherings) instead of just "picking up the pieces" in a conventional post-event model.


Assuntos
COVID-19/transmissão , Férias e Feriados , Rios/microbiologia , SARS-CoV-2 , Animais , Espécies em Perigo de Extinção , Humanos , Índia , Microbiologia da Água , Poluição da Água
4.
Environ Res ; 196: 110946, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33662347

RESUMO

Wastewater-based Epidemiological (WBE) surveillance offers a promising approach to assess the pandemic situation covering pre-symptomatic and asymptomatic cases in highly populated area under limited clinical tests. In the present study, we analyzed SARS-CoV-2 RNA in the influent wastewater samples (n = 43) from four wastewater treatment plants (WWTPs) in Gandhinagar, India, during August 7th to September 30th, 2020. A total of 40 samples out of 43 were found positive i.e. having at least two genes of SARS-CoV-2. The average Ct values for S, N, and ORF 1 ab genes were 32.66, 33.03, and 33.95, respectively. Monthly variation depicted a substantial rise in the average copies of N (~120%) and ORF 1 ab (~38%) genes in the month of September as compared to August, while S-gene copies declined by 58% in September 2020. The SARS-CoV-2 genome concentration was higher in the month of September (~924.5 copies/L) than August (~897.5 copies/L), corresponding to a ~2.2-fold rise in the number of confirmed cases during the study period. Further, the percentage change in genome concentration level on a particular date was found in the lead of 1-2 weeks of time with respect to the official confirmed cases registered based on clinical tests on a temporal scale. The results profoundly unravel the potential of WBE surveillance to predict the fluctuation of COVID-19 cases to provide an early warning. Our study explicitly suggests that it is the need of hour that the wastewater surveillance must be included as an integral part of COVID-19 pandemic monitoring which can not only help the water authorities to identify the hotspots within a city but can provide up to 2 weeks of time lead for better tuning the management interventions.


Assuntos
COVID-19 , Pandemias , Cidades , Humanos , Índia , RNA Viral , SARS-CoV-2 , Águas Residuárias
5.
Sci Total Environ ; 754: 142329, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33254951

RESUMO

For the first time, we present, i) an account of decay in the genetic material loading of SARS-CoV-2 during Upflow Anaerobic Sludge Blanket (UASB) treatment of wastewater, and ii) comparative evaluation of polyethylene glycol (PEG), and ultrafiltration as virus concentration methods from wastewater for the quantification of SARS-CoV-2 genes. The objectives were achieved through tracking of SARS-CoV-2 genetic loadings i.e. ORF1ab, N and S protein genes on 8th and 27th May 2020 along the wastewater treatment plant (106000 m3 million liters per day) equipped with UASB system in Ahmedabad, India. PEG method performed better in removing materials inhibiting RT-qPCR for SARS-CoV-2 gene detection from the samples, as evident from constant and lower CT values of control (MS2). Using the PEG method, we found a reduction >1.3 log10 reduction in SARS-CoV-2 RNA abundance during UASB treatment, and the RNA was not detected at all in the final effluent. The study implies that i) conventional wastewater treatment systems is effective in SARS-CoV-2 RNA removal, and ii) UASB system significantly reduces SARS-CoV-2 genetic loadings. Finally, PEG method is recommended for better sensitivity and inhibition removal during SARS-CoV-2 RNA quantification in wastewater.


Assuntos
COVID-19 , Esgotos , Águas Residuárias , Anaerobiose , Reatores Biológicos , Humanos , Índia , Pandemias , RNA , Eliminação de Resíduos Líquidos
6.
Sci Total Environ ; 746: 141326, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768790

RESUMO

We made the first ever successful effort in India to detect the genetic material of SARS-CoV-2 viruses to understand the capability and application of wastewater-based epidemiology (WBE) surveillance in India. Sampling was carried out on 8 and 27 May 2020 at the Old Pirana Waste Water Treatment Plant (WWTP) at Ahmedabad, Gujarat that receives effluent from Civil Hospital treating COVID-19 patients. All three, i.e. ORF1ab, N and S genes of SARS-CoV-2, were found in the influent with no genes detected in effluent collected on 8 and 27 May 2020. Increase in SARS-CoV-2 genetic loading in the wastewater between 8 and 27 May 2020 samples concurred with corresponding increase in the number of active COVID-19 patients in the city. The number of gene copies was comparable to that reported in untreated wastewaters of Australia, China and Turkey and lower than that of the USA, France and Spain. However, temporal changes in SARS-CoV-2 RNA concentrations need to be substantiated further from the perspectives of daily and short-term changes of SARS-CoV-2 in wastewater through long-term monitoring. The study results SARS-CoV-2 will assist concerned authorities and policymakers to formulate and/or upgrade COVID-19 surveillance to have a more explicit picture of the pandemic curve. While infectivity of SARS-CoV-2 through the excreted viral genetic material in the aquatic environment is still being debated, the presence and detection of genes in wastewater systems makes a strong case for the environmental surveillance of the COVID-19 pandemic.


Assuntos
Infecções por Coronavirus , Pandemias , Pneumonia Viral , Síndrome Respiratória Aguda Grave , Águas Residuárias , Austrália , Betacoronavirus , COVID-19 , China , França , Humanos , Índia/epidemiologia , SARS-CoV-2 , Espanha , Turquia
7.
Chemosphere ; 249: 126126, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32142984

RESUMO

Arsenic (As) and fluoride (F-) are the two most conspicuous contaminants, in terms of distribution and menace, in aquifers around the world. While the majority of studies focus on the individual accounts of their hydro-geochemistry, the current work is an effort to bring together the past and contemporary works on As and F- co-occurrence. Co-occurrence in the context of As and F- is a broad umbrella term and necessarily does not imply a positive correlation between the two contaminants. In arid oxidized aquifers, healthy relationships between As and F- is reported owing desorption based release from the positively charged (hydr)oxides of metals like iron (Fe) under alkaline pH. In many instances, multiple pathways of release led to little or no correlation between the two, yet there were high concentrations of both at the same time. The key influencer of the strength of the co-occurrence is seasonality, environment, and climatic conditions. Besides, the existing primary ion and dissolved organic matter also affect the release and enrichment of As-F- in the aquifer system. Anthropogenic forcing in the form of mining, irrigation return flow, extraction, recharge, and agrochemicals remains the most significant contributing factor in the co-occurrence. The epidemiological indicate that the interface of these two interacting elements concerning public health is considerably complicated and can be affected by some uncertain factors. The existing explanations of interactions between As-F are indecisive, especially their antagonistic interactions that need further investigation. "Multi-contamination perspectives of groundwater" is an essential consideration for the overarching question of freshwater sustainability.


Assuntos
Arsênio/análise , Monitoramento Ambiental , Fluoretos/análise , Água Subterrânea/química , Poluentes Químicos da Água/análise , Água Doce , Metais , Minerais , Mineração , Óxidos
8.
Chemosphere ; 224: 140-150, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30818192

RESUMO

The study attempts to understand arsenic (As) mobilization in a shallow aquifer with depth variation while focusing on the potential co-occurrence of As with priority metals (zinc and lead), using a pilot scale multilevel groundwater monitoring system (MGWS). Groundwater samples (n = 72) were collected bi-weekly (every 15 days) from the multilevel sampler (4.6, 9.2 and 13.8 m depths), installed at Tezpur, Sonitpur district of Brahmaputra floodplain (BFP), Assam, India, for a period of 1 year (August 2013-July 2014). Both geogenic and anthropogenic influences were found to affect the studied unconfined aquifer. At 4.6 m, weathering dominated due to interaction with CO2 and infiltrating water. Prevalent high pH (7.9-8.6) at all three depths in association with strong oxidizing condition (at 4.6 m) during the drier months seem to play a crucial role in desorption based As release. Multivariate analyses revealed that redox potential (ORP) remains the primary controller of As release at all three depths. With depth, stronger anoxic conditions resulted in the dominance of reductive hydrolysis leading to a co-occurrence scenario of As (max 4.6 µgL-1) with Zn (max 2514 µgL-1) and Pb (max 740 µL-1) with influences of anthropogenic modes of activities like agriculture and dry deposition from a brick kiln. Multi-element enrichment is an emerging concern but the bigger picture would be to understand the peculiarities of individual aquifers, as a generalization can lead to missing a ton of information. In this regard, long-term multilevel monitoring can help in the predictive understanding of the vertical stratification and co-occurrences of multi-metals that can subsequently be applied for water production at the safer depths.


Assuntos
Arsênio/análise , Água Subterrânea/análise , Metais/análise , Monitoramento Ambiental/métodos , Índia , Chumbo , Oxirredução , Poluentes Químicos da Água/análise , Zinco
9.
Environ Geochem Health ; 39(1): 161-178, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26979055

RESUMO

In recent years, elevated concentration of arsenic (As) in groundwater in the northeastern states of India has become a major cause of concern. Since many regions of the Brahmaputra plains are reported with groundwater As contamination, an attempt was made to study the As contamination and factors governing its release in the Nagaon district in Brahmaputra floodplain, based on various water types, relation of As with other major ions and with various depth profiles. The origin of groundwater mineralization and the processes responsible for As enrichment in groundwater was determined by calculating saturation index using PHREEQC code. Multivariate statistical analysis was carried out for identification of As-releasing mechanism based on rock-water interaction. Principle component analysis of physicochemical parameters revealed the association of As with SiO2 and Cl- in pre-monsoon and the fact that alkaline condition favors release of As. The relation between As and Fe shows that reductive dissolution of solid Fe oxide and hydroxide phases could be the source of As in Nagaon district. The result of hierarchical cluster analysis indicates that As release could also be associated with the agrochemicals application. Health risk assessment revealed that children are more susceptible to carcinogenic as well as non-carcinogenic health impact with consumption of As-contaminated drinking water. The male population is more susceptible to cancer as compared to females as the average water consumption is higher in case of male. Overall, the study highlights the health risk assessment is a matter of chief concern in this study as the younger generation are at higher risk.


Assuntos
Arsênio/química , Água Subterrânea/química , Medição de Risco , Poluentes Químicos da Água/toxicidade , Humanos , Índia
10.
Chemosphere ; 92(6): 708-13, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23706375

RESUMO

Considerable amount of bottom ash (BA) is produced by tea and paper factories in Northeast India. This significantly deteriorates soil and surface water quality through rapid acidification, releasing sulfur compounds and heavy metals. The present investigation endeavoured to convert this waste to organic manure through vermicomposting by Eisenia fetida. Substantial increment in bioavailability of N, P, K, Fe, Mn and Zn along with remarkable decline in toxic metal like Cr due to vermicomposting was noteworthy. Furthermore, vermicomposted mixtures of Tea Factory BA (TFBA) or Paper Mill BA (PMBA) with organic matter (OM) attributed profuse pod yield of French Bean (Phaseolus vulgaris L.). Hence, bioconversion of TFBA and PMBA is highly feasible through vermicomposting and the converted materials can be utilized as potential organic fertilizer.


Assuntos
Cinza de Carvão/metabolismo , Poluentes Ambientais/metabolismo , Resíduos Industriais/análise , Oligoquetos/metabolismo , Papel , Reciclagem/métodos , Chá , Animais , Biodegradação Ambiental , Cinza de Carvão/análise , Poluentes Ambientais/análise , Metais/análise , Metais/metabolismo , Phaseolus/crescimento & desenvolvimento , Solo/química , Chá/química
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