Fate, source apportionment and fractionation of potentially toxic elements in agricultural soil around a densely populated, semiarid urban center of India: baseline study and ecological risk assessment.

This study is on the outskirts of the rapidly growing city of Jaipur, located in the semiarid region of India and gateway to the 'Great Indian Thar' desert, and focused on potentially toxic elements (PTE) pollution in the farmlands around the city. Concentrations of PTE, along with associated soil parameters such as pH, available nitrogen, organic carbon, phosphorus, and potassium, were estimated in agricultural soil samples near an industrial region on the outskirts of the capital city of the largest state of India. The PTE concentrations in the soil were in the following order: Mn > Pb > Ni > Cr > Cu > Cd. Soil pollution indices, such as the geochemical accumulation index (Igeo), contamination factor (CF), and ecological risk index (ERI), indicated that the soil was moderately to highly polluted. The result of BCR extraction techniques showed Cd is found mainly in the exchangeable and residual fractions, Pb, Mn were found in the reducible as well as residual fractions, while other PTE were mostly bound to residual fraction. All other PTEs are primarily found in the residual fraction, tightly linked with the silicate lattice of soil minerals. Multivariate analysis and the Pearson correlation matrix indicate a common source apportionment for Pb and Cd. Cd, and Pb concentrations in agricultural soil indicate ecological harm that warrants immediate attention and policy-level intervention.

Hydropower: A low-hanging sour-sweet energy option for India.

India is the world's second largest populous nation, fifth largest economy with seventh largest geographical area but experiences high energy poverty. With the lowest per capita energy consumption among world's top ten economies, India ranks at 137 out of 218 nations. Hydropower has the potential to alleviate India's energy asymmetry as well as realize its sustainable growth aspiration of a low-carbon regime. However, hydropower in India has been plagued by debates on human displacement, loss of biodiversity, increased risk of natural disasters, and socio-economic conflicts making it an unpopular energy alternative. Here, we review and address various concerns related to India's hydropower sector, examine scientific evidence, analyze energy policy imperatives, geopolitical considerations, and future directions for a sustainable hydropower policy in India in the context of ongoing climate change. Evidence indicates that besides electricity generation, hydropower infrastructure helps: (i) avert floods, (ii) mitigate the impacts of global warming, and (iii) ensure redistribution of water to arid regions and improve water security. As a part of sustainable hydropower policy, we propose that most of the ecological and social problems associated with hydropower development can be avoided to a great extent through careful planning, proper project design, responsible ownership, and public participation. As short-term measures, we propose: (i) entrepreneurs and planners follow credible and transparent pre-project investigations, (ii) mandatory implementation of environmental management plans, and (iii) better accountability and transparency of statutory bodies as well as hydropower developers. For long-term measures, we suggest: (i) create a 'National Institute of Energy & Environmental Sustainability' to oversee post-project hydropower developmental activities, (ii) streamline various bureaucratic and institutional procedures, and (ii) establish a trans-boundary water management system for seamless and coordinated implementation of hydropower development programs across upstream-downstream nations.

Changes in Salinity, Mangrove Community Ecology, and Organic Blue Carbon Stock in Response to Cyclones at Indian Sundarbans.

Climate change-induced frequent cyclones are pumping saline seawater into the Sundarbans. Fani, Amphan, Bulbul, and Yaas were the major cyclones that hit the region during 2019-2021. This study represents the changes in the soil parameters, mangrove biodiversity and zonation due to the cyclone surges in the Indian Sundarbans between 2017 and 2021. Increasing tidal water salinity (parts per thousand) trends in both pre-monsoon (21 to 33) and post-monsoon (14 to 19) seasons have been observed between 2017 and 2021. A 46% reduction in the soil organic blue carbon pool is observed due to a 31% increase in soil salinity. Soil organic blue carbon has been calculated by both wet digestion and the elemental analyzer method, which are linearly correlated with each other. A reduction in the available nitrogen (30%) and available phosphorous (33%) in the mangrove soil has also been observed. Salinity-sensitive mangroves, such as Xylocarpus granatum, Xylocarpus moluccensis, Rhizophora mucronata, Bruguiera gymnorrhiza, and Bruguiera cylindrica, have seen local extinction in the sampled population. An increasing trend in relative density of salinity resilient, Avicennia marina, Suaeda maritima, Aegiceras corniculatum and a decreasing trend of true mangrove (Ceriops decandra) has been observed, in response to salinity rise in surface water as well as soil. As is evident from Hierarchical Cluster Analysis (HCA) and the Abundance/Frequency ratio (A/F), the mangrove zonation observed in response to tidal gradient has also changed, becoming more homogeneous with a dominance of A. marina. These findings indicate that cyclone, climate change-induced sea level rise can adversely impact Sustainable Development Goal 13 (climate action), by decreasing organic soil blue carbon sink and Sustainable Development Goal 14 (life below water), by local extinction of salinity sensitive mangroves.

Distribution, speciation, and bioaccumulation of potentially toxic elements in the grey mangroves at Indian Sundarbans, in relation to vessel movements.

Sundarban is the world's largest mangrove wetland and home of 4.6 million people (Indian part), whose principal mode of communication is motorized boats (ferries). This study shed light on the role played by ferry movement in the speciation (following the BCR three-step sequential extraction method), ecological impact and bioaccumulation of potentially toxic elements (PTEs) in plant tissues (root and lamina) of grey mangrove (Avicennia marina) found near the five ferry ghats (ports). One-way ANOVA showed variation in major soil parameters (silt, clay, organic carbon, pH, Electrical conductivity) and PTEs (As, Cd, Cr, Cu, Hg, and Pb) between sites. Sequential extraction revealed that Cd was present in the 'exchangeable' form across the sites, Pb was in the 'reducible' form, and the rest of the PTEs were majorly found in 'residual' phase. Pollution indices revealed moderate to heavy contamination and considerable potential ecological risk due to Cd. Pearson correlation statistics and concentration variations indicate a relation between Pb and ferry movement frequency in the sites. Higher bioconcentration of Pb in the roots of A. marina, indicates phytostabilization action. Translocation factor for Cd in the leaves, indicates phytoextraction by A. marina. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed a close association between vehicle movement and Hg, Pb, Silt fraction, electrical conductivity, Cr, and As. This study recommends regular pollution monitoring across Sundarbans, as the PTEs in sediment-plant matrix can impact the higher trophic levels, human health through possible biomagnification in the detritus food chain, and can adversely impact the existing conservation initiatives.

Variations in Soil Blue Carbon Sequestration between Natural Mangrove Metapopulations and a Mixed Mangrove Plantation: A Case Study from the World's Largest Contiguous Mangrove Forest.

Sundarban is the world's largest mangrove wetland. This study, conducted in 2016, to compare blue carbon sequestration with different natural metapopulations and a four-year-old Avicennia marina (30% area)-Rhizophora mucronata (70% area)-mixed mangrove plantation under anthropoganic stress. The aims of the study is to find out the variations in soil ecological function indicators (pH, electrical conductivity, bulk density, soil texture, available nitrogn, phosphorus and soil organic carbon) and key ecological service indicator (soil blue carbon pool) between sites. Simpson's Index of dominance, diversity and Shannon-Weiner Index revealed that all the sites are under ecological stress, with the Suaeda maritima-dominated mudflat having the least biodiversity. It is also revealed that pH and electrical conductivity were highest in Suaeda maritima and Phoenix padulosa-dominated metapopulations, whereas organic carbon was the highest under the mangrove plantation and Avicennia marina-dominated site. Available nitrogen was recorded highest in the community with the Sonneretia sp.-Avicennia marina association. The mixed mangrove plantation had the highest blue carbon pool. The species diversity was not found to be related with the distance from the nearby conserved mangrove forest, contrary to the island biogeography theory. This study concludes with a recommendation of mixed mangrove plantations to restore the degraded saline mudflats along the human settlements across the globe.

Circulating anti-nuclear autoantibodies in COVID-19 survivors predict long COVID symptoms.

BACKGROUND: Autoimmunity has been reported in patients with severe coronavirus disease 2019 (COVID-19). We investigated whether anti-nuclear/extractable-nuclear antibodies (ANAs/ENAs) were present up to a year after infection, and if they were associated with the development of clinically relevant post-acute sequalae of COVID-19 (PASC) symptoms. METHODS: A rapid-assessment line immunoassay was used to measure circulating levels of ANAs/ENAs in 106 convalescent COVID-19 patients with varying acute phase severities at 3, 6 and 12 months post-recovery. Patient-reported fatigue, cough and dyspnoea were recorded at each time point. Multivariable logistic regression model and receiver operating curves were used to test the association of autoantibodies with patient-reported outcomes and pro-inflammatory cytokines. RESULTS: Compared to age- and sex-matched healthy controls (n=22) and those who had other respiratory infections (n=34), patients with COVID-19 had higher detectable ANAs at 3 months post-recovery (p<0.001). The mean number of ANA autoreactivities per individual decreased between 3 and 12 months (from 3.99 to 1.55) with persistent positive titres associated with fatigue, dyspnoea and cough severity. Antibodies to U1-snRNP and anti-SS-B/La were both positively associated with persistent symptoms of fatigue (p<0.028, area under the curve (AUC) 0.86) and dyspnoea (p<0.003, AUC=0.81). Pro-inflammatory cytokines such as tumour necrosis factor (TNF)-α and C-reactive protein predicted the elevated ANAs at 12 months. TNF-α, D-dimer and interleukin-1ß had the strongest association with symptoms at 12 months. Regression analysis showed that TNF-α predicted fatigue (ß=4.65, p=0.004) and general symptomaticity (ß=2.40, p=0.03) at 12 months. INTERPRETATION: Persistently positive ANAs at 12 months post-COVID are associated with persisting symptoms and inflammation (TNF-α) in a subset of COVID-19 survivors. This finding indicates the need for further investigation into the role of autoimmunity in PASC.

Does COVID-19 lockdowns have impacted on global dengue burden? A special focus to India.

BACKGROUND: The world has been battling several vector-borne diseases since time immemorial. Socio-economic marginality, precipitation variations and human behavioral attributes play a major role in the proliferation of these diseases. Lockdown and social distancing have affected social behavioral aspects of human life and somehow impact on the spread of vector borne diseases. This article sheds light into the relationship between COVID-19 lockdown and global dengue burden with special focus on India. It also focuses on the interconnection of the COVID-19 pandemic (waves 1 and 2) and the alteration of human behavioral patterns in dengue cases. METHODS: We performed a systematic search using various resources from different platforms and websites, such as Medline; Pubmed; PAHO; WHO; CDC; ECDC; Epidemiology Unit Ministry of Health (Sri Lanka Government); NASA; NVBDCP from 2015 until 2021. We have included many factors, such as different geographical conditions (tropical climate, semitropic and arid conditions); GDP rate (developed nations, developing nations, and underdeveloped nations). We also categorized our data in order to conform to COVID-19 duration from 2019 to 2021. Data was extracted for the complete duration of 10 years (2012 to 2021) from various countries with different geographical region (arid region, semitropic/semiarid region and tropical region). RESULTS: There was a noticeable reduction in dengue cases in underdeveloped (70-85%), developing (50-90%), and developed nations (75%) in the years 2019 and 2021. The dengue cases drastically reduced by 55-65% with the advent of COVID-19 s wave in the year 2021 across the globe. CONCLUSIONS: At present, we can conclude that COVID-19 and dengue show an inverse relationship. These preliminary, data-based observations should guide clinical practice until more data are made public and basis for further medical research.

Current Overviews on COVID-19 Management Strategies.

The coronavirus pandemic hit the world lately and caused acute respiratory syndrome in humans. The causative agent of the disease was soon identified by scientists as SARS-CoV-2 and later called a novel coronavirus by the general public. Due to the severity and rapid spread of the disease, WHO classifies the COVID-19 pandemic as the 6th public health emergency even after taking efforts like worldwide quarantine and restrictions. Since only symptomatic treatment is available, the best way to control the spread of the virus is by taking preventive measures. Various types of antigen/antibody detection kits and diagnostic methods are available for the diagnosis of COVID-19 patients. In recent years, various phytochemicals and repurposing drugs showing a broad range of anti-viral activities with different modes of actions have been identified. Repurposing drugs such as arbidol, hydroxychloroquine, chloroquine, lopinavir, favipiravir, remdesivir, hexamethylene amiloride, dexamethasone, tocilizumab, interferon-ß, and neutralizing antibodies exhibit in vitro anti-coronaviral properties by inhibiting multiple processes in the virus life cycle. Various research groups are involved in drug trials and vaccine development. Plant-based antiviral compounds such as baicalin, calanolides, curcumin, oxymatrine, matrine, and resveratrol exhibit different modes of action against a wide range of positive/negative sense-RNA/DNA virus, and future researches need to be conducted to ascertain their role and use in managing SARS-CoV-2. Thus this article is an attempt to review the current understanding of COVID- 19 acute respiratory disease and summarize its clinical features with their prospective control and various aspects of the therapeutic approach.

Bioaccumulation of potentially toxic elements in three mangrove species and human health risk due to their ethnobotanical uses.

The aim of this study was to assess probabilistic human health risk due to ethnobotanical usage of Avicennia officinalis, Porteresia coarctata and Acanthus ilicifolius. The study was conducted at the tannery outfall near Sundarban (Ramsar wetland, India) mangrove ecosystem  affected by potentially toxic elements (Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn). Total metal concentrations (mg kg-1) were considerably higher in the polluted rhizosphere namely, Cd (1.05-1.97), Cu (36.3-38.6), Cr (144-184), Hg (0.04-0.19), Mn (163-184), Ni (37.7-46.4), Pb (20-36.6), and Zn (97-104). Ecological risk index indicated low to moderate ecological risk in this site, whereas the ecological risk factor showed high potential ecological risk due to Cd pollution. BCR Sequential extraction of metals showed more exchangeable fraction of Cd (47-55%), Cr (9-13%), Hg (11-13%), and Pb (11-15%), at the polluted site. Mercury, though present in trace amount in sediment, showed the highest bioaccumulation in all the three plants. Among the toxic trio, Hg showed the highest bioaccumulation in A. officinalis, Cd in P. coarctata but Pb has the lowest bioaccumulation potential in all the three species. Occasional fruit consumption of A. officinalis and dermal application of leaf, bark of A. officinalis (antimicrobial), A. ilicifolius (anti-inflammatory, pain reliever when applied on wounds) indicated negligible human health risk. However, long-term consumption of P. coarctata (wild rice variety) seeds posed health risk (THQ>1) both in adults and children age groups. This study concludes that nature of ethnobotanical use and metal contamination levels of the mangrove rhizosphere can impact human health. The transfer process of potentially toxic elements from rhizosphere to plants to human body should be considered while planing pollution mitigation measures. Graphical Abstract.

Potential human health hazard due to bioavailable heavy metal exposure via consumption of plants with ethnobotanical usage at the largest chromite mine of India.

Usage of native plant species for traditional medicine or nutritional supplement is a popular practice among various cultures. But consumption of plants growing on polluted soil can cause serious human health hazard due to bioaccumulation of toxic heavy metals. Present study deals with the ecological and human health impact of heavy metals, in six native plant species with ethnobotanical significance growing at the largest chromite mine of India. Exchangeable, oxidizable, reducible and residual fractions of the metals in plant rhizosphere were analyzed. Only 2-6% of total Cr (270-330 mg/kg) and Ni (150-190 mg/kg) at the mining site is bioavailable. Cd showed highest bioavailability (~ 60%) in mining site posing very high ecological risk (1055-5291) followed by Ni (1297-2124) and Cr (309-1105). The heavy metals in the shoot of the targeted plants were about 0.7 to 80 times higher than the standard limit as per Indian statutory body. The total hazard quotient (THQ) by the consumption of plants growing in mining region was very high (> 1) and varied from 2.6 to 5.9 in adult and 0.6-1.3 in children, while in non-mining region the THQ of same plants indicates low risk (< 1). This study indicates THQ (adult) in the order of, Euphorbia hirta (5.9) > Calotropis procera (4.9) > Argemone mexicana (3.6) > Vernonia cinerea (3.5) > Pteridium latiusculum (3.4) > Tridax procumbens (2.6) through consumption pathway growing in mine soil. This study concludes that consumption of plants growing in heavy metal polluted soil should be avoided due to their potential health hazard.

Distribution of heavy metals and associated human health risk in mine, agricultural and roadside soils at the largest chromite mine of India.

This study accessed the levels of Cd, Cr, Fe, Mn, Ni, Pb and Zn concentration in soils of different locations (mine, roadside, agricultural and control sites) of Sukinda chromite mine (the India's largest Chromite mine and listed among the world's ten most polluted regions). Geo-accumulation (Igeo) index indicates that the mine, agricultural and roadside soils are 'heavily to extremely contaminated' due to Cr, Ni, Pb and Cd, hence human residing/working in this region can have health hazards due to contaminated soil via different exposure pathways. The concentration of heavy metals (mg/kg) in mine site vary between 52.35 and 244.8 (Cr6+), 12,030.2 and 31,818.6 (Cr3+), 5460.4 and 8866.0 (Ni), 70.02 and 208.6 (Pb), 0.95 and 5.3 (Cd), 209.1 and 360.4 (Mn), 21,531.8 and 28,847 (Fe) and 221 and 349.3 (Zn). Fe, Cr6+, Cr3+ and Ni concentration in soil follows an order of mine site > road sites > agricultural lands > control forest sites. Principal component analysis and hierarchical cluster analysis indicate Cd, Cr, Fe, Ni and Pb as major pollutants in the region. Cancer Risk is 'high' in both adult (5.38E-04) and children (4.45E-04) in mining sites and 'low' to 'very low' in agricultural and road side soils. The hazard index for all the heavy metals in a mining areas is varied from 2.9 to 5.2 in adult and 2.8-5.1 in children, indicating 'high' to 'very high' non-cancer risk due to significant contribution of Ni, Pb and Cr6+ concentration (73, 11 and 10%, respectively).

How to communicate climate change 'impact and solutions' to vulnerable population of Indian Sundarbans? From theory to practice.

INTRODUCTION: Global consciousness on climate change problems and adaptation revolves around the disparity of information sharing and communication gap between theoretical scientific knowledge at academic end and practical implications of these at the vulnerable populations' end. Coastal communities facing socio-economic stress, like densely populated Sundarbans, are the most affected part of the world, exposed to climate change problems and uncertainties. This article explores the successes of a socio-environmental project implemented at Indian Sundarbans targeted towards economic improvement and aims at communicating environmental conservation through organized community participation. CASE DESCRIPTION: Participatory rural appraisal (PRA) and the wealth rank tool (WRT) were used to form a "group based organization" with 2100 vulnerable families to give them knowledge about capacity building, disaster management, resource conservation and sustainable agriculture practices. Training was conducted with the selected group members on resource conservation, institution building, alternative income generation activities (AIGA) like, Poultry, Small business, Tricycle van, Organic farming and disaster management in a participatory mode. The climate change 'problems-solutions' were communicated to this socio-economically marginalized and ostracized community through participatory educational theater (PET). DISCUSSION AND EVALUATION: WRT revealed that 45 % of the population was under economic stress. Out of 2100 beneficiaries', 1015 beneficiaries' started organic farming, 133 beneficiaries' adopted poultry instead of resource exploitive livelihood and 71 beneficiaries' engaged themselves with small business, which was the success stories of this project. To mitigate disaster, 10-committees were formed and the endemic knowledge about climate change was recorded by participatory method validated through survey by structured questionnaire. As a part of this project 87 ha of naked deforested mudflat was reclaimed with endangered mangroves involving target community members aimed to sequester CO2, control soil erosion and act as a barrier during natural disasters. CONCLUSION: This case study concluded that participatory method of communication, aiming not only to communicate theoretical knowledge, but also to devise adaptation strategies through conservation of endemic knowledge, popularizing sustainability through Micro Finance Institutions and promoting AIGA along with motivating vulnerable community to restore degraded forest lands, could be a effective solution to practically combat climate change problems.