Reassessing the availability of crop residue as a bioenergy resource in India: A field-survey based study.

Second-generation bioenergy, a carbon neutral or negative renewable resource, is crucial to achieving India's net-zero emission targets. Crop residues are being targeted as a bioenergy resource as they are otherwise burned on-field, leading to significant pollutant emissions. But estimating their bioenergy potential is problematic because of broad assumptions about their surplus fractions. Here, we use comprehensive surveys and multivariate regression models to estimate the bioenergy potential of surplus crop residues in India. These are with high sub-national and crop disaggregation that can facilitate the development of efficient supply chain mechanisms for its widespread usage. The estimated potential for 2019 of 1313 PJ can increase the present bioenergy installed capacity by 82% but is likely insufficient alone to meet India's bioenergy targets. The shortage of crop residue for bioenergy, combined with the sustainability concerns raised by previous studies, imply a need to reassess the strategy for the use of this resource.

Accounting of the Use and Emissions of Polychlorinated Biphenyl Compounds (PCBs) in India, 1951-2100.

Polychlorinated biphenyl compounds (PCBs) are highly toxic organic chemicals still prevalent in the environment. While global inventories of the use and emissions of PCBs have been developed, estimates for individual countries determined using bottom-up approaches are few and often show different trends from the global inventory. Here, we determine the past, present, and future consumption and emissions of PCBs in India. A mass balance model was used to estimate middle (low-high) emissions in the period 1950-2100. Up to 7296 tonnes of PCBs have been used in transformers. PCBs imported as wastes are estimated to be approximately 5000 (2400-9100) tonnes. Total emissions from the use and disposal of transformers, industrial processes, and imported waste disposal are estimated to become 13 (0.1-537) tonnes, 89.26 (0.5-178) tonnes, 63 (3-910) tonnes, respectively, in the period 1950-2100. Congener-specific emissions are relatively high for low-chlorinated PCBs (-8, 18, 28, 31, 52, 101, 110, 118, 153, range: 0.1-118 tonnes). We find that industrial emissions are becoming important sources of PCBs and may become predominant, depending on emission scenarios.

Distribution of organochlorine pesticides in surface and deep waters of the Southern Indian Ocean and coastal Antarctic waters.

Antarctica is a remote and pristine region. Yet it plays a vital role in biogeochemical cycles of global anthropogenic contaminants, such as persistent organic pollution (POPs). This work reports the distribution of legacy and new POPs in surface and depth profiles/deeper water of the Southern Indian Ocean (SIO) and the coast of Antarctica (COA). Samples were collected during the 10th Indian Southern Ocean expedition (SOE-10) in the year 2017. Concentrations of ∑HCH (hexachlorocyclohexane), ∑DDT (dichlorodiphenyltrichloroethane), and ∑ENDO (endosulfan) in surface seawater from the SIO region ranged between not detected (ND) to 1.21 pg/Liter (pg L-1) (average. ± s.d.: 0.35 ± 0.42 pg L-1), ND to 1.83 pg L-1 (0.69 ± 84 pg L-1), and ND - to 2.06 pg L-1 (0.56 ± 0., 88 pg L-1), respectively. The concentrations of ∑HCH, ∑DDT, and ∑ENDO in COA ranged from ND to 0.98 pg L-1 (0.25 ± 0.27 pg L-1), ND to 3.61 pg L-1(0.50 ± 1.08 pg L-1), and ND to 2.09 pg L-1 (0.45 ± 0.84 pg L-1), respectively. Concentrations of isomers of endosulfan, and largely of HCHs, suggested an aged source. Some concentration ratios of α-to γ-HCH were close to 1, indicating a contribution from ongoing sources. Results indicate the important role of ocean currents in mediating the transport and detection of OCPs. As such, OCPs dynamics in deeper oceans may play an important role in OCPs cycling in the marine environment.

Reducing mercury emissions from coal-fired power plants in India: Possibilities and challenges.

Coal combustion is the largest source of power in India at the moment. This combustion also emits trace amounts of hazardous substances such as mercury. Mercury is a global pollutant with the potential for long-range transport and ability to persist in the environment, bioaccumulate and cause toxicity. Controlling emissions of mercury from coal-fired power plants (CFPPs) is recognized by the Minamata Convention on Mercury as an important step in curbing the harmful effects of mercury to the environment and humans. India has been identified as one of the top emitters of mercury to the atmosphere, and coal combustion contributes to more than half of these emissions. Here, we discuss the current state of regulations on mercury emissions from CFPPs in India, the current information on mercury from CFPP stacks, and the possible way forward. Present data suggest that mercury specific emission control technologies are not required to comply with the regulatory requirements. As such, any reduction in mercury emissions will rely on co-benefits obtained from technologies to control emissions of other pollutants such as flue gas desulphurization, or methods to increase the efficiencies of CFPP such as coal washing. Additional reductions may be made from a business-as-usual scenario if the energy mix of India changes to renewable non-fossil fuel-based energy at an accelerated pace. Quantitative studies assessing the role of such climate change policies on mercury emissions reduction are recommended.

Mercury in the Environment Around Industrially Impacted Locations in India: A Mini-Review.

India is a major emitter of mercury to the environment. This mini-review condenses the information available since 2008 on mercury in air, soil, sediment, biota and human biomarkers near industrial locations. Information from eight regions was analyzed. More than 40% of studies did not report sufficient QA/QC information on analysis methods. Highest quality was observed for studies on human biomarkers, biota, and sediments, and the lowest on water quality. Concentrations of mercury in sediments (up to 3650 µg/kg), human biomarkers (up to 31 µg/g) and fish (up to 3 µg/g) in the vicinity of coal-fired power plants and iron and steel were high in general, and sometimes comparable to or higher than the global guideline, screening or reference values. Overall, impacts of industrial activities on mercury pollution of surrounding environment were evident, and warrant a speedy assessment of other industrial areas and implementation of mitigation measures.

Performance of a green wall (Total Value Wall™) at high greywater loading rates and Life Cycle Impact Assessment.

Nature-based greywater (GW) treatment and reuse in urban areas has become an up-and-coming option. A 14.4 m2 green wall system called Total Value Wall (TVW) was installed at a terraced house in Gent (Belgium) for treating GW and reusing the effluent for toilet flushing. In a previous study, the TVW was loaded at 7 L.m-2.d-1 and efficiently removed TSS (67%), COD (43%), BOD5 (83%) and total coliforms (log 2), but a number of issues were reported related to nutrient leaching from the substrate, and the excessive retention time in the storage tanks. In this study results are reported from a follow-up study during which an adapted TVW was subjected to both higher hydraulic and pollutant loading rates in order to investigate the treatment capability of TVW. The design of the system, i.e. substrate contained in geotextile bags, did not sustain the higher hydraulic loading rates as excessive leakage occurred. Despite this, the higher pollutant loading rates still resulted in an acceptable effluent quality with 15 mg.L-1 TSS (90%), 85 mg.L-1 COD (82%), and 15 mg.L-1 BOD5 (95%). Ammonium, E. coli and total coliforms were removed with removal rates of 98%, 63% (0.4 log units), and 36% (0.2 log units), respectively. Finally, a life cycle assessment (LCA) was performed for the TVW with and without treating GW to analyze the environmental burden. The LCA impacts showed that replacing tap water and chemical fertilizer by GW, and the reuse of effluent, have a positive impact. However, the energy use for pumping has a major impact and should be minimized by using an efficient pump and distribution system to reduce the overall footprint.

Insilco identification and characterization of superoxide dismutase gene family in Brassica rapa.

Superoxide Dismutase SODs are defense associated proteins that detoxify ROS and primarily serve as scavengers. They have been described in numerous plant species, but their in-depth characterization in Brassica rapa has not been reported. Therefore, the present investigation on genome wide study of SOD gene family was conducted to identify BrSOD genes, their domain-based organization, gene structure analysis, phylogenetic analysis, intron-exon structure of genes and expression analysis. The sequence characterization of Super oxide dismutase gene family in Brassica rapa, their syntenic associateship of conserved motifs and phylogenetic correlationship, prediction of cis-elements and determing the expression analysis in distinct tissues namely plant callus, root, stem, leaf, flower, and silique under abiotic conditions have been analysed using different software's. The study on SOD gene family identified 17 BrSOD genes which were grouped into eight BrCu-ZnSODs and nine BrFe-MnSODs domain-based organization. Furthermore, the conserved character of BrSODs were confirmed by intron-exon organisation, motif arrangements and domain architectural investigations. Expression analysis using RNA Sequence data of different developmental stages proclaimed that genes were manifested in all six tissues with an exception of BrCu-ZnSOD3, which was not manifested in roots; however, whose transcript was detected in all other tested tissues. The study has genome wide insight into the occurrence and functional specifications of BrSOD gene family in Brassica rapa that can be potentially utilized in breeding program for resilience to climate change and abiotic stresses tolerance Brassica variety.

Portable X-ray Fluorescence as a Rapid Determination Tool to Detect Parts per Million Levels of Ni, Zn, As, Se, and Pb in Human Toenails: A South India Case Study.

Chronic exposure to inorganic pollutants adversely affects human health. Inductively coupled plasma mass spectrometry (ICP-MS) is the most common method used for trace metal(loid) analysis of human biomarkers. However, it leads to sample destruction, generation of secondary waste, and significant recurring costs. Portable X-ray fluorescence (XRF) instruments can rapidly and nondestructively determine low concentrations of metal(loid)s. In this work, we evaluated the applicability of portable XRF as a rapid method for analyzing trace metal(loid)s in toenail samples from three populations (n = 97) near the city of Chennai, India. A Passing-Bablok regression analysis of results from both methods revealed that there was no proportional bias among the two methods for nickel (measurement range ∼25 to 420 mg/kg), zinc (10 to 890 mg/kg), and lead (0.29 to 4.47 mg/kg). There was a small absolute bias between the two methods. There was a strong proportional bias (slope = 0.253, 95% CI: 0.027, 0.614) between the two methods for arsenic (below detection to 3.8 mg/kg) and for selenium when the concentrations were lower than 2 mg/kg. Limits of agreement between the two methods using Bland-Altman analysis were derived for nickel, zinc, and lead. Overall, a suitably calibrated and evaluated portable XRF shows promise in making high-throughput assessments at population scales.

Co-disposal of lignite fly ash and coal mine waste rock for neutralisation of AMD.

Waste rocks (WRs) from a lignite-producing coalfield and fly ash (FA) produced from the same lignite have been investigated in this study with a primary objective to determine the potential for co-disposal of WRs and FA to reduce the environmental contamination. Mixing WRs with FA and covering WRs with FA have been investigated. Particle size effect caused ≤2 mm particles to produce low pH (~2) and metal-laden leachates, indicating higher sulphide minerals' reactivity compared to larger particles (≤10 mm, pH ~ 4). Co-disposal of FA as mixture showed an instantaneous effect, resulting in higher pH (~3-6) and better leachate quality. However, acidity produced by secondary mineralisation caused stabilisation of pH at around 4.5-5. In contrast, the pH of the leachates from the cover method gradually increased from strongly acidic (pH ~ 2) to mildly acidic (pH ~ 4-5) and circumneutral (pH ~ 7) along with a decrease in EC and elemental leaching. Gradually increasing pH can be attributed to the cover effect, which reduces the oxygen diffusion, thus sulphide oxidation. FA cover achieved the pH necessary for secondary mineralisation during the leaching experiment. The co-disposal of FA as cover and/or mixture possesses the potential for neutralisation and/or slowing down AMD and improving leachate quality.

Mercury in skin-care products in India and consumer exposure risks.

We report concentrations of mercury in skin-care products in India and the associated health risks. Mercury concentrations were 0.11 µg/kg (median; 5th percentile-95th percentile = 0.04-0.58 µg/kg; n = 24) in body lotions, 0.22 µg/kg (0.04-0.38 µg/kg, n = 10) in moisturizing lotions, 0.67 µg/kg (0.30-1.33 µg/kg, n = 8) in blemish balms, 0.16 µg/kg (0.06-7.43 µg/kg, n = 11) in bleaches, 0.13 µg/kg (0.04-0.98 µg/kg, n = 34) in skin lightning (fairness) creams manufactured within the country, and 9.24 × 106 µg/kg (2.92 × 106-3.17 × 107 µg/kg, n = 14) in imported skin lightning (fairness) creams, much higher than the 1 ppm (1 ppm = 103 µg/kg) regulatory limit. Probabilistic human health risk assessment for adult women (age > 21 y) revealed that computed hazard quotients from dermal exposure to the high-mercury fairness creams were >100 in all cases. The mass of mercury entering into the society via skin-care products is highly sensitive to the mass of high-mercury fairness creams that is imported to India; ten tonnes of import can introduce 29-317 kg of mercury every year. As such, analysis and labeling of mercury contents in skin-care products by manufacturers, and raising awareness among regulatory authorities to restrict the import of high-mercury fairness creams, is required.

RESILIENT: A robust statistical method for estimating multiple VOC sources from limited field measurements.

Air pollution due to haphazard industrialization has become a major concern in developing countries. Yet, enforcement of related norms remains problematic because violators cannot easily be pinpointed among closely situated industrial units. Accordingly, it has become imperative to equip regulatory authorities with an economical yet accurate tool that quickly locates emission sources and estimates emission rates. Against this backdrop, we propose RESILIENT, a method for Robust Estimation of Source Information from LImited field measuremENTs, which exhibits significant statistical robustness and accuracy even when the data are collected using a low-cost error-prone sensor. In our field experiment, where ground truth was unavailable, the sources estimated to be inactive based on the complete set of measurements were found inactive (up to three decimal places of accuracy) at least 72% of the time even when estimated using just 54% of random measurements. In that setting, rate estimates of active sources were also found to be statistically robust. For direct validation of RESILIENT, we considered a separate public dataset involving 10 tracer experiments, and obtained a significant correlation coefficient of 0.89 between estimated and recorded emission rates, and that of 0.99 between predicted and measured concentration levels at sensor locations.

Mercury in Dental Amalgam, Online Retail, and the Minamata Convention on Mercury.

The Minamata Convention on Mercury (ref. 1) is a global treaty to protect human and environmental health from adverse effects of the toxic element mercury and its compounds. During the Third Conference of Parties (COP-3) in November 2019, elimination of the use of dental amalgam in oral health care was discussed. Dental amalgam is one of the most commonly used restorative materials in oral health care due to its strength and longevity (ref. 2). However, the use of mercury in an amalgam adds to global environmental mercury pollution and can contribute to adverse health effects on humans and other organisms. The outcomes of the COP-3 meeting included a call for information on the availability at a national scale, the economic and technical feasibility of alternatives, and the associated risks or benefits. In this feature, we discuss the risks and benefits of dental amalgam, the global tracking of availability and procurement, and the implications and realities for global phase out. We suggest a better accounting of mercury use in dental amalgam is needed with sales being made only to registered practitioners via a Know Your Customer approach.

Lewis Base-Switched [3 + 3] and [4 + 2] Annulation Reactions of δ-Acetoxy Allenoates with Cyclic N-Sulfonyl Imines: Divergent Synthesis of Functionalized α-Pyridyl Acetates and Teraryl Scaffolds.

Under metal-free conditions, δ-acetoxy allenoates react with cyclic N-sulfonyl imines (sulfamidate imines/sulfonyl imines) to afford functionalized 2-pyridinyl acetates (α-pyridyl acetates) or teraryl motifs by a simple Lewis base switch. Thus, while DBU/Na2CO3 combination-directed [3 + 3] annulation involves sulfonyl elimination via O-S or C-S bond cleavage, affording 2-pyridinyl acetates, Ph3P-catalyzed [4 + 2] annulation leads to functionalized teraryls via Mannich coupling and C-N bond cleavage with retention or cleavage of the sulfamoyloxy group depending on the reaction conditions.

Patterns of Mandibular Fractures and Associated Comorbidities in Peshawar, Khyber Pakhtunkhwa.

Objectives The objective of this study was to assess patterns of mandibular fractures and associated comorbidities in Peshawar, Pakistan. Methodology This multicenter, descriptive, cross-sectional study analyzed patients aged >15 years who had been clinically or radiographically diagnosed with mandibular fractures from January to December, 2015. Patients with pathological fractures or bomb-blast injuries were excluded. Data were analyzed using IBM SPSS Statistics for Windows, Version 20.0 (IBM Corp., Armonk, NY). Results The 138 patients diagnosed with mandibular fractures in 2015 included 108 men (78.3%) and 30 women (21.7%), with a male preponderance of 3.6:1. Most patients (56%) were aged 15-25 years, followed by those aged 26-35 years (26%). The most frequent cause of fractures was road traffic accidents (RTAs; 59.42%), followed by falls (18.8%). RTAs were predominant in men (89%); whereas, falls were predominant in women (80%). Fractures due to firearm injuries and interpersonal violence were more frequent in men (p <0.001). In patients with unilateral fractures, the most common fracture site was the parasymphysis (24.6%) followed by the symphysis (10.1%). In patients with bilateral fractures, the most common fracture sites were the parasymphysis and condyle (11.6%), followed by the parasymphysis and angle (8.0%). Conclusions RTA was the most frequent cause of mandibular fracture and trauma. Mandibular fractures were more common in men than women, with most patients aged 15-25 years. The most common fracture site was the parasymphysis.

Variation of green liquor dregs from different pulp and paper mills for use in mine waste remediation.

The geotechnical, chemical, and mineralogical properties of green liquor dregs (GLDs) generated as byproducts from five paper mills were investigated to assess their buffering and heavy metal immobilization capacities and their roles as water and oxygen barriers. One type of GLD was further studied to test the effects of the retrieval process and the storage, drying, and hydration of GLD. The high water retention capacity of the GLDs is valuable for limiting O2 diffusion. Laboratory results showed that the GLDs had hydraulic conductivities of 3.7 × 10-9-4.6 × 10-8 m/s and varied regularly in plasticity. The chemical and mineralogical compositions of the GLDs varied greatly, reflecting the raw material used to produce paper and the process used to retrieve GLDs. Although they had high total heavy metal contents, none of the leached elements from the GLDs (L/S 10 cm3/kg) exceeded the European Union's limits for landfills of non-hazardous waste. The GLDs exhibited high buffering capacities. In a supplementary test, the buffering capacities varied (0.0041-0.0114 M H+/g GLD) over 72 d after acid was added to the GLD. Changing the filtration process did not greatly affect the GLDs' properties but mainly affected the hydraulic conductivity, total heavy metal contents and sulfur content. Analyzing the storage of GLDs is necessary in the mining industry because remediation measures require large amounts of material over short periods. The buffering capacity of the dried GLD decreased slightly. The effect of dewatering caused by the mixing of 2% Na-lignosulfate with GLD (w/w) was low.

Climate change and overfishing increase neurotoxicant in marine predators.

More than three billion people rely on seafood for nutrition. However, fish are the predominant source of human exposure to methylmercury (MeHg), a potent neurotoxic substance. In the United States, 82% of population-wide exposure to MeHg is from the consumption of marine seafood and almost 40% is from fresh and canned tuna alone1. Around 80% of the inorganic mercury (Hg) that is emitted to the atmosphere from natural and human sources is deposited in the ocean2, where some is converted by microorganisms to MeHg. In predatory fish, environmental MeHg concentrations are amplified by a million times or more. Human exposure to MeHg has been associated with long-term neurocognitive deficits in children that persist into adulthood, with global costs to society that exceed US$20 billion3. The first global treaty on reductions in anthropogenic Hg emissions (the Minamata Convention on Mercury) entered into force in 2017. However, effects of ongoing changes in marine ecosystems on bioaccumulation of MeHg in marine predators that are frequently consumed by humans (for example, tuna, cod and swordfish) have not been considered when setting global policy targets. Here we use more than 30 years of data and ecosystem modelling to show that MeHg concentrations in Atlantic cod (Gadus morhua) increased by up to 23% between the 1970s and 2000s as a result of dietary shifts initiated by overfishing. Our model also predicts an estimated 56% increase in tissue MeHg concentrations in Atlantic bluefin tuna (Thunnus thynnus) due to increases in seawater temperature between a low point in 1969 and recent peak levels-which is consistent with 2017 observations. This estimated increase in tissue MeHg exceeds the modelled 22% reduction that was achieved in the late 1990s and 2000s as a result of decreased seawater MeHg concentrations. The recently reported plateau in global anthropogenic Hg emissions4 suggests that ocean warming and fisheries management programmes will be major drivers of future MeHg concentrations in marine predators.

Microbes Producing L-Asparaginase free of Glutaminase and Urease isolated from Extreme Locations of Antarctic Soil and Moss.

L-Asparaginase (L-asparagine aminohydrolase, E.C. 3.5.1.1) has been proven to be competent in treating Acute Lymphoblastic Leukaemia (ALL), which is widely observed in paediatric and adult groups. Currently, clinical L-Asparaginase formulations are derived from bacterial sources such as Escherichia coli and Erwinia chrysanthemi. These formulations when administered to ALL patients lead to several immunological and hypersensitive reactions. Hence, additional purification steps are required to remove toxicity induced by the amalgamation of other enzymes like glutaminase and urease. Production of L-Asparaginase that is free of glutaminase and urease is a major area of research. In this paper, we report the screening and isolation of fungal species collected from the soil and mosses in the Schirmacher Hills, Dronning Maud Land, Antarctica, that produce L-Asparaginase free of glutaminase and urease. A total of 55 isolates were obtained from 33 environmental samples that were tested by conventional plate techniques using Phenol red and Bromothymol blue as indicators. Among the isolated fungi, 30 isolates showed L-Asparaginase free of glutaminase and urease. The L-Asparaginase producing strain Trichosporon asahii IBBLA1, which showed the highest zone index, was then optimized with a Taguchi design. Optimum enzyme activity of 20.57 U mL-1 was obtained at a temperature of 30 °C and pH of 7.0 after 60 hours. Our work suggests that isolation of fungi from extreme environments such as Antarctica may lead to an important advancement in therapeutic applications with fewer side effects.

Mercury levels in human hair in South India: baseline, artisanal goldsmiths and coal-fired power plants.

India is a major emitter of mercury to the environment, mainly due to emissions from coal-fired power plants. Consumption of fish and rice, two important pathways for human exposure to mercury, is particularly high in South India. Here, we report concentrations of total mercury in hair (THghair) in 668 participants from South India. Three cities were covered: (i) a city on the east coast with four active coal-fired thermal power plants (Nellore), (ii) a city on the west coast with no major mercury source (Vasco da Gama), and (iii) a metropolitan city in the interior with no major mercury source (Hyderabad). Geometric mean of THghair of the entire study population is 0.14 µg/g (95% confidence interval, CI: 0.13-0.15 µg/g). Significant predictor variables are age, fish consumption, and occupations such as dental studies, subsistence fishing, and artisanal goldsmithing (which is different from artisanal scale gold mining). Our results support the hypothesis that people living in a city with active coal-fired power plants may have higher THghair than those in cities with no major mercury source.

Effects of the co-disposal of lignite fly ash and coal mine waste rocks on AMD and leachate quality.

Lignite fly ash (FA) and waste rocks (WRs) were mixed in three different ratios (1:1, 1:3 and 1:5) and studied to compare the effects of adding FA on acid mine drainage generation from coal mining WRs, leachability of elements and the potential occurrence of the secondary minerals. FA mixed with WRs showed significant differences in pH levels compared to previous research. The 1:1 mixture performed best of all the three mixtures in terms of pH and leachability of elements, mainly due to the higher proportion of FA in the mixture. The pH in the 1:1 mixtures varied between 3.3 and 5.1 compared to other mixtures (2.3-3.5). Iron and SO42- leached considerably less from the 1:1 mixture compared to the others, indicating that the oxidation of sulphides was weaker in this mixture. Aluminium leached to a high degree from all mixtures, with concentrations varying from mg L-1 to g L-1. The reason behind this increase is probably the addition of FA which, due to acidic conditions and the composition of the FA, increases the availability of Al. For the same reason, high concentrations of Mn and Zn were also measured. Geochemical modelling indicates that the 1:1 mixture performs better in terms of precipitation of Al3+ minerals, whereas Fe3+ minerals precipitated more in mixtures containing less FA. These results suggest that, with time, the pores could possibly be filled with these secondary minerals and sulphate salts (followed by a decrease in sulphide oxidation), improving the pore water pH and decreasing the leachability of elements. Since grain size plays a crucial role in the reactivity of sulphides, there is a risk that the results from the leaching tests may have been influenced by crushing and milling of the WR samples.