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The large-scale emissions of airborne particulates from burning of agricultural residues particularly over the upper Indo-Gangetic Plain (IGP) have often been associated with frequent formation of haze, adverse health impacts, modification in aerosol climatology and thereby aerosols impact on regional climate. In this study, short-term variations in aerosol climatology during extreme biomass burning emissions over IGP, and thereby to regional climate were investigated. Size-segregated particulate concentration was initially measured and submicron particles (PM1.1) were found to dominate particulate mass within the fine mode (PM2.1). Particulate bound water-soluble ions were mainly secondary in nature, primarily composed of sulfate and nitrate. There was evidence of gaseous NH3 dominating neutralization of acidic aerosol species (SO42-) in submicron particles, in contrast to crustal dominating neutralization in coarser particulates. Variation in black carbon mass ratio was found to be influenced by local sources, while sudden increase in concentration was consistent with high Delta-C, referring to biogenic emissions. Influence of biomass burning emissions were established using specific organic (levoglucosan), inorganic (K+ and NH4+) and satellite (UV Aerosol Index, UVAI) tracers. Levoglucosan was the most abundant within submicron particles (649±177 ng m-3), with a very high ratio (>50) against other anhydrosugars, indicating exclusive emissions from burning of agriculture residues. Temporal variations of all the tracers were consistent, while NH4+ was more closely associated to levoglucosan. Spatio-temporal distribution of aerosol and few trace gases (CO and NO2) were evaluated using both space-borne active and passive sensors, and a significant increase in columnar aerosol loading (AOD: 0.98) was evident during extreme biomass burning emissions, with presence of absorbing aerosols (UVAI > 1.5) having low aerosol layer height (~1.5 km). A strong intraseasonality in aerosol cross-sectional altitudinal profile was even noted from CALIPSO, referring dominance of smoke and polluted continental aerosols across IGP. Possible transport mechanism of biomass smoke was established using cluster analysis and concentration weighted of air mass back-trajectories. Short-wave aerosol radiative forcing (ARF) was further simulated considering intraseasonality in aerosol properties, which resulted in considerable increase of atmospheric ARF (135 Wm-2) and heating rate (4.3 K day-1) during extreme biomass burning emissions compared to non-dominating one (56 Wm-2, 1.8 K day-1). We therefore conclude that influence of biomass burning emissions on regional aerosol climatology must need to be studied in much finer scale to improve parameterization of aerosol/-climate model across the region. [ABSTRACT FROM AUTHOR]

A robust method was developed using LC-ESI-MS/MS-based identification and quantification of 103 fortified pesticides in a mango fruit drink. Variations in QuEChERS extraction (without buffer, citrate, and/or acetate buffered) coupled with dispersive clean-up combinations were evaluated. Results showed 5 mL dilution and citrate buffered QuEChERS extraction with anhydrous (anhy) MgSO 4 clean-up gave acceptable recovery for 100 pesticides @ 1 μg mL -1 fortification. The method was validated as per SANTE guidelines (SANTE/11813/2021). 95, 91, and 77 pesticides were satisfactorily recovered at 0.1, 0.05, and 0.01 μg mL -1 fortification with HorRat values ranging from 0.2-0.8 for the majority. The method showed matrix enhancement for 77 pesticides with a global uncertainty of 4.72%-23.89%. The reliability of the method was confirmed by real sample analysis of different brands of mango drinks available in the market. The greenness assessment by GAPI (Green Analytical Procedure Index) indicated the method was much greener than other contemporary methods., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Tippannanavar, Banerjee, Shekhar, Sahu, Singh, Narayanan, Rudra, Chakrabarti, Gupta and Singh.)

Abundance of fine particulate-bound 16 priority polycyclic aromatic hydrocarbons (PAHs) was investigated to ascertain its sources and potential carcinogenic health risks in Varanasi, India. The city represents a typical urban settlement of South Asia having particulate exposure manyfold higher than standard with reports of pollution induced mortalities and morbidities. Fine particulates (PM 2.5 ) were monitored from October 2019 to May 2020, with 32% of monitoring days accounting ≥100 μgm -3 of PM 2.5 concentration, frequently from November to January (99% of monitoring days). The concentration of 16 priority PAHs varied from 24.1 to 44.6 ngm -3 (mean: 33.1 ± 3.2 ngm -3 ) without much seasonal deviations. Both low (LMW, 56%) and high molecular weight (HMW, 44%) PAHs were abundant, with Fluoranthene (3.9 ± 0.4ngm -3 ) and Fluorene (3.5 ± 0.3ngm -3 ) emerged as most dominating PAHs. Concentration of Benzo(a)pyrene (B(a)P, 0.5 ± 0.1ngm -3 ) was lower than the national standard as it contributed 13% of total PAHs mass. Diagnostic ratios of PAH isomers indicate predominance of pyrogenic sources including emissions from biomass burning, and both from diesel and petrol-driven vehicles. Source apportionment using receptor model revealed similar observation of major PAHs contribution from biomass burning and fuel combustion (54% of source contribution) followed by coal combustion for residential heating and cooking purposes (44%). Potential toxicity of B[a]P equivalence ranged from 0.003 to 1.365 with cumulative toxicity of 2.13ngm -3 . Among the PAH species, dibenzo[h]anthracene contributed maximum toxicity followed by B[a]P, together accounting 86% of PAH induced carcinogenicity. Incremental risk of developing cancer through lifetime exposure (ILCR) of PAHs was higher in children (3.3 × 10 -4 ) with 56% contribution from LMW PAHs, primarily through ingestion and dermal contact. Adults in contrast, were more exposed to inhale airborne PAHs with cumulative ILCR of 2.2 × 10 -4 . However, ILCR to PM 2.5 exposure is probably underestimated considering unaccounted metal abundance thus, require source-specific control measures., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2023 Elsevier Ltd. All rights reserved.)

White rot fungi possess an enzymatic system that is non-specific to any pesticide and can be used for pesticide detoxification in biobeds. The present study evaluated potential of Phanerochaete chrysosporium to degrade co-applied atrazine and fipronil in ash or biochar biomixtures. Five biomixtures were prepared by partially replacing compost in rice straw-compost biomixture (BM) with 10% rice husk ash (RHA), 10% sugarcane bagasse ash (SBA), and 1 and 5% wheat straw biochar (WBC). Results suggested that after 30 days P. chrysosporium augmented biobeds resulted in 60.52-72.72% atrazine and 69.57-72.52% fipronil degradation. Hydroxyatrazine and fipronil sulfone were detected as the only metabolite of atrazine and fipronil, respectively, and were further degraded. Although, SBA significantly enhanced atrazine degradation, RHA or SBA had no significant effect on fipronil degradation. WBC (5%) slowed down degradation of both pesticides., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Monitoring pesticide residue levels becomes crucial to maintain quality and guarantee food safety as the consumption of onion green leaves and immature and mature bulbs (either raw or processed) rises. A field experiment was conducted for two consecutive seasons with quizalofop-p-ethyl (5% EC) at 50 and 100 g a.i. ha -1 to evaluate weed control efficiency and to determine terminal residues. Post-emergence application of fop herbicide at 100 g a.i. ha -1 kept the weed density and dry weight reasonably at a lower level and enhanced the productivity of onion with higher economic returns. A rapid, sensitive, and analytical method was developed using high-performance liquid chromatography (HPLC) with excellent linearity (r 2 > 0.99). The limit of quantification for quizalofop-p-ethyl was established at 0.04 mg kg -1 with signal to noise (S/N) ratio ≥ 10. The method was successfully applied and initial quantified residues were in the range of 2.5-4.4 mg kg -1 irrespective of seasons and doses. Finally, the presence of targeted herbicide residues in harvested samples was confirmed by liquid chromatography tandem mass spectrometry (LC-MS/MS) under optimized operating conditions. Dietary risk assessment assured harvested onions were safe for consumption at the recommended dose. It also can be concluded that quizalofop ethyl did not adversely influence soil micro-organisms at standard rates of application., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Retrieval accuracy and stability of two operational aerosol retrieval algorithms, Deep Blue (DB) and Dark Target (DT), applied on Visible Infrared Imaging Radiometer Suite (VIIRS) on-board Suomi National Polar-orbiting Partnership (S-NPP) satellite were evaluated over South Asia. The region is reported to be highly challenging to accurate estimation of satellite-based aerosol optical properties due to variations in surface reflectance, complex aerosol system and regional meteorology. Performance of both algorithms were initially evaluated by comparing their ability to retrieve aerosol signal over the complex geographical region under specific air pollution emission scenario. Thereafter, retrieval accuracy was investigated against 10 AERONET sites across South Asia, selected based on their geography and predominance aerosol types, from year 2012-2021. Geo-spatial analysis indicates DB to efficiently retrieve fine aerosol features over bright arid surfaces, and for smoke/dust dominating events whereas DT was better to identify small fire events under dark vegetated surface. Both algorithms however, indicate unsatisfactory retrieval accuracy against AERONET having 56-59% of valid retrievals with high RMSE (0.30-0.33) and bias. Overall, DB slightly underpredicted AOD with -0.02 mean bias (MB) whereas DT overpredicted AOD (MB: 0.13), with seasonality in their retrieval efficiency against AERONET. Time-series analysis indicates stability in retrieving AOD and match-up number for both algorithms. Retrieval bias of DB and DT AOD against AERONET AOD under diverse aerosol loading, aerosol size, scattering/absorbing aerosol, and surface vegetation coverage scenarios revealed DT to be more influenced by these conditions. Error analysis indicates at low AOD (≤0.2), accuracy of both DB and DT were subject to underlying vegetation coverage. At AOD>0.2, DB performed well in retrieving coarse aerosols whereas DT was superior when fine aerosols dominated. Overall, accuracy of both VIIRS algorithms require further refinement to continue MODIS AOD legacy over South Asia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Fine airborne particles (diameter <2.5 μm; PM 2.5 ) are recognized as a major threat to human health due to their physicochemical properties: composition, size, shape, etc. However, normally only size-fraction-specific particle concentrations are monitored. Interestingly, although the aerosol type is reported as part of the aerosol optical depth retrieval from satellite observations, it has not been utilized, to date, as an auxiliary information/co-variate for PM 2.5 prediction. We developed Random Forest (RF) and eXtreme Gradient Boosting (XGBoost) models that account for this information when predicting surface PM 2.5 . The models take as input only widely available data: satellite aerosol products with full cover and surface meteorological data. Distinct models were developed for AOD of specific aerosol types. Both the RF and XGBoost models performed well, showing moderate-to-high cross-validated adjusted R 2 (RF: 0.753-0.909; XGBoost: 0.741-0.903), depending on the aerosol type and other covariates. The weighted performance of the specific aerosol-type models was higher than of the RF and XGBoost baseline models, where all the AOD retrievals were used together (the common practice). Our approach can provide improved risk estimates due to exposure to PM 2.5 , better resolved radiative forcing calculations, and tailored abatement surveillance of specific pollutants/sources., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: David Broday reports financial support was provided by Israel Science Foundation., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The application of biocontrol agents in farm operations for pest control programs is gaining priority and preference globally. Effective delivery, infectivity of the biocontrol agents, and quality shelf-life products containing these bioagents are vital parameters responsible for the success of biopesticides under field conditions. In the present study, moisture-retaining bio-insecticidal dustable powder formulation (SaP) of Steinernema abbasi ( Sa ) infective juveniles (IJs) was developed and assessed for its shelf life, physicochemical profile, and bio-efficacy against subterranean termite under field conditions. Formulation exhibited free-flowing character, with pH of 6.50-7.50, and apparent density in the range 0.50-0.70 g cm -3 . The bioefficacy study for two rabi seasons (2020-2021, and 2021-2022) in wheat and chickpea grown in an experimental farm heavily infested with subterranean termites ( Odontotermes obesus ) revealed a significant reduction in plant damage due to pest attack in formulation-treated plots, monitored in terms of relative number of infested tillers in wheat and infested plants in chickpea fields. The reduced damage to the crop caused by termite was reflected in the relative differences in the growth and yield attributes as well. The study establishes the potential of the developed product as a biopesticide suitable for organic farming and integrated pest management operations.

Microplastics (MPs) are ubiquitous in our environment. Its presence in air, water, and soil makes it a serious threat to living organisms and has become a critical challenge across ecosystems. Present study aimed to assess the abundance of MPs in aerosols and street dust in Varanasi, a typical urban city in Northern India. Airborne particulates and street dust samples were collected from various sampling sites around Varanasi City. The physical identification of MPs was conducted by binocular microscopy, fluorescence microscopy, and scanning electron microscopy (SEM), while elemental analysis was made by energy-dispersive X-ray (EDX). Finally, Fourier-transform infrared spectroscopy (FTIR) was used for chemical characterization of MPs. Presence of MPs in both aerosols and street dust from all selected sampling sites was confirmed, however with varying magnitude. MPs of different colors having the shape of fragments, films, spherules, and fibers were recorded in the study while fragments (42%) in street dust and fibers (44%) dominated in aerosols. Majority of the MPs were < 1 mm in size and were primarily polypropylene, polystyrene, polyethylene, polyethylene terephthalate, polyester, and polyvinyl chloride types. The EDX spectra showed the presence of toxic inorganic contaminants like metallic elements on MPs, especially elements like aluminum, cadmium, magnesium, sodium, and silicon found to adsorb on the MPs. Presence of MPs in the airborne particulates and street dust in Varanasi is reported for the first time, thus initiating further research and call for a source-specific management plan to reduce its impact on human health and environment., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Based on our previous study in minimal medium, Kocuria rosea and Aspergillus sydowii were identified as the best microbes for degradation of mixture of polyaromatic hydrocarbons (PAHs). The present study reports PAH degradation potential of these microbes in free and immobilized form. PAHs were extracted using QuEChERS-mediated process followed by quantification by high performance liquid chromatography. The microbial consortium of Kocuria rosea + Aspergillus sydowii was formulated in three bio-formulations, namely (i) bentonite-alginate composite beads; (ii) water dispersible granule composite using guar gum-nanobentonite; and (iii) composites of carboxymethyl cellulose-bentonite and were applied in PAH fortified (100 µg g -1 ) sandy loam soil. Results suggested that degradation data fitted well to first order kinetics as in most of the cases, the values of correlation coefficient (r) were > 0.95. The half-life (t 1/2 ) values for PAHs in the uninoculated control soil were: naphthalene (10.43 d), fluorene (22.43 d), phenanthrene (24.64 d), anthracene (38.47 d), and pyrene (34.34 d). Inoculation of soil with free culture microbial consortium (without or with nutrient) and bio-formulation of degrading cultures enhanced degradation of all PAHs and half-life values were significantly reduced for each PAH: naphthalene (1.76-2.00 d), fluorene (2.52-6.65 d), phenanthrene (4.61-6.37 d), anthracene (9.01-12.22 d), and pyrene (10.98-15.55 d). Among different bio-formulations, guar gum-nanobentonite-based composite exhibited better efficacy for degradation of naphthalene, fluorene, phenanthrene, anthracene, and pyrene. The addition of microbial consortium in PAH fortified soil increased 16S rRNA gene copies of Alphaproteobacteria and Bacteroidetes, compared to the uninoculated, PAH-fortified control. The microbial functional gene assays showed that the gene copies of amoA, nirK, nirS, and anammox increased, suggesting nitrogen regulation in the PAH-fortified soil., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Three-dimensional (temporal-spatial-vertical) climatology of South Asian summertime (MAMJ, 2010-2019) aerosols and aerosol sub-types was explored using multiple high-resolution satellite-based observations and reanalysis dataset. Vertical stratification of aerosol layer and aerosol sub-types was identified using observation from space-borne lidar. Aerosol optical depth (AOD) was particularly high across the Indo-Gangetic Plain (IGP; AOD ± SD: 0.56 ± 0.12) and over eastern coast of India (AOD: 0.6-0.8), with prevalence of heterogeneous aerosol sub-types having strong spatial gradient. Clearly, aerosols over north-western arid part were highly absorbing (Ultra-violet Aerosol Index, UVAI > 0.80) and coarse (Ångström exponent, AE < 0.8), with an indication of desert/-mineral dust aerosols. In contrast, fine and moderate to non-absorbing aerosols (UVAI: 0.20-0.50) dominate from central to lower IGP, including in Bangladesh, with signature of anthropogenic emissions. Prevailing aerosols over twelve South Asian cities were classified into six aerosol sub-types constraining their particle size and UV-absorbing potential. Overall, mineral dust, smoke and urban aerosols were the three major aerosol sub-types that prevail across South Asia during summer. In particular, 58-70 % of retrieval days over Karachi and Multan were dust dominated; 57-64 % days were dust or urban aerosols dominated over Lahore, Delhi, Kanpur and Varanasi, and 56-77 % days were smoke or urban aerosols dominated over Dhaka, Kathmandu, Chennai, Mumbai, Colombo and Nagpur. Prevailing aerosols were vertically stratified as 50-70 % of total AOD was retrieved <2 km from the surface except in few cities where 70-80 % of AOD was retrieved <3 km height. Mineral dust and/or urban aerosols emerged as the most abundant aerosol types near the surface (<1 km) in all the cities except in Chennai, with their abundance remained as a function of emission sources and geographical location., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Environmental crises, declining factor productivity, and shrinking natural resource is a threat to global agricultural sustainability. The task is much more daunting in the Indo-Gangetic northern plains of India, where depletion of the underground water table and erratic rains due to the changing climate pose a major challenge to agriculture. To address these challenges a field investigation was carried out during 2016-2018 to test the efficacy of biopolymeric superabsorbent hydrogels namely Pusa Hydrogel (P-hydrogel: a semi-synthetic cellulose derivative-based product) and kaolin derivative of Pusa Hydrogel (K-hydrogel: semi-synthetic cellulose derivative) to assess their effect on crop and water productivity, soil moisture, root dynamics, and economics of soybean (Glycine max L.)-wheat (Triticum aestivum L.) system under three irrigation regimes namely full irrigation, limited irrigation and rainfed. The results revealed that the full irrigation along with P-hydrogel led to enhanced grain yield, biomass yield, and water productivity (WP) of soybean (1.61-10.5%, 2.2-9.5%, and 2.15-21.8%, respectively) and wheat (11.1-18.3%, 12-54% and 11.1-13.1%, respectively) over control plots. Likewise, under water stressed plots of rainfed conditions with P-hydrogel exhibited 52.7 and 20.6% higher system yields (in terms of wheat equivalent yield) over control and other combinations during the respective study years. Whereas the magnitude of increase in system yield under limited irrigation with P-hydrogel was ~ 15.1% and under full irrigation with P-hydrogel was 8.0-19.4%. Plots treated with P-hydrogel retained 3.0-5.0% higher soil moisture compared to no-hydrogel plots, while K-hydrogel treated plots held the lower moisture (4.0-6.0%) than the control. In terms of profitability, full irrigation along with P-hydrogel plots registered 12.97% higher economic returns over control. The results suggested that P-hydrogel (2.5 kg ha -1 ) reduces runoff water loss in full irrigation applied plots and retained more water, where loss of water is more thus reduces number of irrigations. Hence P-hydrogel with irrigation water is a viable option for sustainable production of soybean-wheat systems in the Indo-Gangetic plains of India and other similar eco-regions of the world., (© 2022. The Author(s).)

Very high spatially resolved satellite-derived ground-level concentrations of particulate matter with an aerodynamic diameter of less than 2.5 μm (PM 2.5 ) have multiple potential applications, especially in air quality modeling and epidemiological and climatological research. Satellite-derived aerosol optical depth (AOD) and columnar water vapor (CWV), meteorological parameters, and land use data were used as variables within the framework of a linear mixed effect model (LME) and a random forest (RF) model to predict daily ground-level concentrations of PM 2.5 at 1 km × 1 km grid resolution across the Indo-Gangetic Plain (IGP) in South Asia. The RF model exhibited superior performance and higher accuracy compared with the LME model, with better cross-validated explained variance ( R 2 = 0.87) and lower relative prediction error (RPE = 24.5%). The RF model revealed improved performance metrics for increasing averaging periods, from daily to weekly, monthly, seasonal, and annual means, which supported its use in estimating PM 2.5 exposure metrics across the IGP at varying temporal scales (i.e., both short and long terms). The RF-based PM 2.5 estimates showed high PM 2.5 levels over the middle and lower IGP, with the annual mean exceeding 110 μg/m 3 . As for seasons, winter was the most polluted season, while monsoon was the cleanest. Spatially, the middle and lower IGP showed poorer air quality compared to the upper IGP. In winter, the middle and lower IGP experienced very poor air quality, with mean PM 2.5 concentrations of >170 μg/m 3 .

Multi-locational supervised field trials were conducted in different agro-climatic regions in India to study dissipation of trifloxystrobin and tebuconazole in tomato after spraying a combination formulation (trifloxystrobin 25% + tebuconazole 50%, 75WG) at recommended doses: (i) single (trifloxystrobin 87.5 g a.i. ha -1  + tebuconazole 175 g a.i. ha -1 ) and (ii) double (trifloxystrobin 175 g a.i. ha -1  + tebuconazole 350 g a.i. ha -1 ). Fruit samples were extracted with ethyl acetate using a modified QuEChERS method. The residues (parent fungicides + metabolite) were analyzed and confirmed by GC-ECD and GC-MS, respectively. The half-life (t 1/2 ) of trifloxystrobin and tebuconazole in tomato varied from 1.08 to 1.72 and 1.13 -to 1.64 days at single; and 1.27 to 2.13 and 1.24 to 1.96 days at double dose, respectively. Since maximum residue limit (MRL) at pre-harvest interval (PHI) of 5 days is impractical, as tomato is usually harvested and consumed almost everyday after the last spray, the risk assessment was performed at minimum PHI of 1 day. Accordingly, on the basis of supervised field trial data and using OECD MRL calculator, MRL of 0.5 and 1.5 mg kg -1  at single dose were proposed for trifloxystrobin and tebuconazole in/on tomato, respectively., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Burning of wheat and rice straw on field, after crop harvest, is a quick, cheap and an easy way for land clearing. The ashes generated after burning are mixed with soils and due to their alkaline nature, they may affect the degradation of applied herbicides. Therefore, present paper reports degradation of sulfosulfuron in aqueous suspension of the wheat (WSA) and rice (RSA) straw ashes. The results suggested that both ashes significantly enhanced sulfosulfuron dissipation in water and effect was more with the RSA. The solution pH affected sulfosulfuron dissipation and in control buffers (no ash) herbicide degradation followed the order: acidic > alkaline > neutral. Addition of the RSA significantly increased sulfosulfuron degradation in buffers, but effect was more evident at neutral and alkaline pH. The study has relevance in assessing degradation of sulfosulfuron in soils where crop residues are burned for land clearing.

Fine particulates (PM 2.5 ) constitute dominant proportion of airborne particulates and have been often associated with human health disorders, changes in regional climate, hydrological cycle and more recently to food security. Intrinsic properties of particulates are direct function of sources. This initiates the necessity of conducting a comprehensive review on PM 2.5 sources over South Asia which in turn may be valuable to develop strategies for emission control. Particulate source apportionment (SA) through receptor models is one of the existing tool to quantify contribution of particulate sources. Review of 51 SA studies were performed of which 48 (94%) were appeared within a span of 2007-2016. Almost half of SA studies (55%) were found concentrated over few typical urban stations (Delhi, Dhaka, Mumbai, Agra and Lahore). Due to lack of local particulate source profile and emission inventory, positive matrix factorization and principal component analysis (62% of studies) were the primary choices, followed by chemical mass balance (CMB, 18%). Metallic species were most regularly used as source tracers while use of organic molecular markers and gas-to-particle conversion were minimum. Among all the SA sites, vehicular emissions (mean ± sd: 37 ± 20%) emerged as most dominating PM 2.5 source followed by industrial emissions (23 ± 16%), secondary aerosols (22 ± 12%) and natural sources (20 ± 15%). Vehicular emissions (39 ± 24%) also identified as dominating source for highly polluted sites (PM 2.5 >100 μgm -3 , n = 15) while site specific influence of either or in combination of industrial, secondary aerosols and natural sources were recognized. Source specific trends were considerably varied in terms of region and seasonality. Both natural and industrial sources were most influential over Pakistan and Afghanistan while over Indo-Gangetic plain, vehicular, natural and industrial emissions appeared dominant. Influence of vehicular emission was found single dominating source over southern part while over Bangladesh, both vehicular, biomass burning and industrial sources were significant., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A number of 4'-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3'-butene-2'-ketoxime N-O-alkyl ethers were prepared, separated into their E and Z isomers, and characterized on the basis of (1)H NMR and mass spectroscopy. These compounds were tested in vitro for antifungal activity against four important phytopathogenic fungi, namely, Sclerotium rolfsii , Rhizoctonia bataticola , Macrophomina phaseolina , and Sclerotinia sclerotiorum . E isomers of 4'-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3'-butene-2'-ketoxime N-O-propyl ether (ED(50) = 32.36 microg mL(-1)) and 4'-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3'-butene-2'-ketoxime N-O-(1''-methyl) ethyl ether (ED(50) = 35.50 microg mL(-1)) showed maximum antifungal activity against R. bataticola and S. rolfsii, respectively, whereas 4'-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3'-butene-2'(Z)-ketoxime N-O-pentyl ether was found to be active against M. phaseolina (ED(50) = 31.08 microg mL(-1)) and S. sclerotiorum (ED(50) 21.39 microg mL(-1)), respectively. The Z isomer of 4'-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3'-butene-2'-ketoxime N-O-pentyl ether, which was found to be most effective, was tested against S. sclerotiorum in a greenhouse at 1 and 5% concentrations. The 5% aqueous emulsion of 4'-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3'-butene-2'(Z)-ketoxime N-O-pentyl ether suppressed disease development in pea by 90-95% as compared with the untreated infested soil in the greenhouse after 21 days of treatment.

4'-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-3'-buten-2'-ketoxime-N-O-alkyl ethers have been synthesized starting from alpha-ionone, separated into their E and Z isomers and characterized on the basis of (1)H-NMR and mass spectra.