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Linear growth of atmospheric particulate matter (PM) over south Asia is one of the significant problems affecting human health and climate change. In addition, these particulate matters have the potential to absorb and scatter solar radiation, causing a disturbance in the earth radiation budget resulting in this region facing several floods and droughts, excessive glacier melting, loss of a million lives, and many more in the last two decades. This context aim to provide a brief knowledge of PM2.5 chemical composition and their optical properties. To assess, existing field studies conducted after the year 2000 were reviewed and summarized in terms of geographical, temporal and seasonal variation across the region. It is seen that PM2.5 were significantly increased by 25.04% in the last two decades. Annual PM2.5 was up to 10 times the prescribed limit set by world health organization (WHO) guidelines. Annual PM2.5 was higher in the northern than southern cities, and more increased in Indo-Gangetic plains (IGP) than coastal and southern region (CASR) and high altitude (HA) regions. The highest seasonal variation occurred in the winter months. Organic carbon and elemental carbon contribute nearly 31% of the annual average PM2.5 ranged from 14 to 70%. Higher variability in the percentage contribution of organic carbon and elemental carbon suggests different sources mainly influences this region. Biomass and fossil fuels, vehicular emission, and secondary aerosol are the major source factors in the inland region, while marine salt and soil dust are dominant fractions observed in a coastal area. Light absorbing brown carbon contributes significant amount in this region, and it’s clearly seen by aerosol optical depth, varied from 0.04 to 1 in the entire region.

Toxic gaseous organic air pollutants such as benzene, toluene, ethylbenzene, and xylene isomers (m, p, and o-x) (BTEX) are considered hazardous due to its adverse impacts on human health and on climate change. This review identifies the major research questions addressed so far and the research gap in research articles, published between 2001 and 2022, focusing on the ambient BTEX concentrations in different locations in India along with its sources, ozone formation potential (OFP), and associated health risks. The ambient levels of BTEX were also compared with those of other Asian countries. A comparison of ambient BTEX levels with different microenvironments in India is also presented. BTEX concentrations were found in the range of 30.95 to 317.18 µg m−3 and multi-fold higher in urban environments than those measured in the rural air. In most reported studies, the order of occurrence of BTEX compounds was toluene > benzene > xylene isomers > ethylbenzene and winter had higher concentrations than in other seasons, including summer. As far as BTEX levels in classified areas of urban environments are concerned, traffic locations have shown the highest BTEX concentrations, followed by residential, commercial, and industrial locations. OFP indicated that xylene isomers and toluene contributed to ozone formation. The major gaps in reported studies on BTEX measurement are (1) source apportionment; (2) impact on lower tropospheric chemistry, human health, and climate change; and (3) removal techniques from air. published

Eleven potentially toxic metal(loid)s (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), proven source markers of mineral based coal-fired industrial emissions and vehicular exhausts, were analysed using the four steps sequential extraction method to evaluate metal(loid)s concentration, in total and fractions of bioavailable and non-bioavailable for fine (PM2.5) and coarse (PM10–2.5) particulate modes. A total of 26-day-wise samples with three replications (total number of samples = 78) were collected in January–December 2019 for each PM10 and PM2.5 at an urban-residential site in India. In both the coarse and fine particulate modes, Pb and Cr have respectively shown the highest and lowest total concentrations of the measured metal(loid)s, indicating the presence of coal-fired power plants and heavy vehicular activities near to study area. In addition, Mn has shown highest bioavailable fraction for both coarse and fine particulate modes. More than 50 % of metal(loid)s concentration, in total to a bioavailable fraction (BAF) were observed in case of As, Cd, Cr, Co, Mn, Ni, and Pb of PM2.5. Mn and Zn have shown similar behaviour in the case of coarse particulate mode. Source apportionment of metal(loid)s bioavailable fractions using positive matrix factorization (PMF 5.0) has found three significant sources: crustal and natural dust (30.04 and 39 %), road traffic (49.57 and 20 %), and industrial emission (20.39 and 41 %) for coarse and fine particulate mode, respectively. Cancer risk through the inhalation pathway was high in total concentration but lower in BAF concentration in both age groups (children and adults). published

Groundwater resource in this few decades has been challenging in India due to intense agricultural, industrial and mining activities which make groundwater quality exposed to contaminants. This review article deals with results of groundwater quality monitoring and assessment works conducted in India during the year 2000 to 2015. Previously published research articles of study region with the theme of groundwater quality have been discussed for concentrations of heavy metals, ions, water-soluble organics and inorganics along with its associated health impacts. Several methodologies were used for various chemical contaminants quantification and a wide range of statistical approaches was also applied for their source identification and/or apportionment. The major groundwater pollutants were F? , NO? , As, V, Cd, Cr, Cu, Fe, Pb, Co, Mn, Ni, Zn, Polycyclic Aromatic Hydrocarbons (PAHs), Organochlorine Pesticides (OCPs) etc. monitored in India in higher concentration than standard permissible limits regulated by various international and national agencies like World Health Organization (WHO), United States Environmental Protection Agency (USEPA), American Publi c Health Association (APHA) and Bureau of Indian Standards (BIS). Studies reported that millions of people are suffering from chronic heavy metal poisoning causing cancer, cardiovascular diseases, affecting central nervous system, brain, liver, kidney etc., while 1.6 million children expire every year from ailment for which polluted drinking water is a primary cause.

Atmospheric PM2.5 pollution, has shown potential impact on the human health in general, thus it requires to look into the chemical characteristics of PM2.5 masses for designing effective policies to reduce health risks amongst public under exposure. The study carried out, here, has presented the ambient PM2.5 concentrations, concentrations of chemical components and associated health risks over rural and urban environments in the area of mineral based coal-fired industrial areas of central India for a period of one year (2015–16). Overall 260 PM2.5 samples, collected from rural, urban and industrial sites, were analyzed for various elements Al, As, Ca, Hg, Cr, Co, Cu, Fe, Mn, K, Cd, Mo, Ni, Pb, Se, Sb, Na, Mg, K, V and Zn, ions such as Na+, Mg2+, K+, Ca2+, F–, Cl–, NH4+, NO3–, SO42– and carbonaceous matter. The annual average PM2.5 mass concentrations were found to be ~2 to ~6 folds higher than the annual National Ambient Air Quality standard (40 µg m–3). Further this study also evaluates, carcinogenic and non-carcinogenic health risks associated with ambient PM2.5 exposures (via ingestion, inhalation and dermal). The elemental species that have shown non-carcinogenic risks for both children and adults of all three sites are: Co, Mn, Ni (rural), As, Cd, Cr, Mn, Ni, V (urban and industrial sites). Similarly, the excess carcinogenic risks, in total, from Cd, Co, Cr, Ni, Pb was found to be higher than acceptable limits (10–6 to 10–4).

To study the influence of fireworks in atmospheric aerosols and their effect on health during the extreme firework days, fireworks tracer metals and carbonaceous species in size-distributed aerosols in the lower troposphere at Raipur in eastern central India were investigated during the 2018 Deepawali festival. Aerosol samples were collected, before Deepawali period (BDP, n = 5), during Deepawali period (DDP, n = 5) and after Deepawali period (ADP, n = 5). Bimodal size-distribution with intense fine mode peak was found for Na during DDP. Bimodal distribution with fine mode intense peak was found for K during DDP. The bimodal size distribution of K was found common for other events because of biomass burning emissions, whereas high intense peak during DDP indicated mixed sources from biomass burning and fireworks. During DDP, K and Ca were well correlated (r2 = 0.93) together. Strong metal-metal correlations were found between the following pairs, Zn–Fe, Cu–Fe and Cu–Ca, which indicated the similar firecrackers burning source. The atmospheric aging of aerosols was also found significantly high during fireworks days. Aging of aerosols were higher because of heterogeneous reactions of SO2 and NOx on aerosols directly emitted from fireworks. The observed high values of inhalation dose of elemental carbon during DDP period imposed higher risk of respiratory diseases. This study has provided carbonaceous fractions composition data as a tool to detect the aging processes of fireworks in ultra-fine, fine and coarse mode particles during the extreme firework days. Inhalation doses were calculated to establish potential influence on human health.

Solid-biomass-fuel residential cookstoves are the largest source of aerosol emissions in the Indian subcontinent. For assessing radiative forcing due to this pollutant source, laboratory-generated ...

We report a smartphone–paper-based sensor impregnated with cetyltrimethylammonium bromide modified silver nanoparticles (AgNPs/CTAB) for determination of Fe3+ in water and blood plasma samples. The methodology for determination of Fe3+ is based on the change in signal intensity of AgNPs/CTAB fabricated on a paper substrate after the deposition of analyte, using a smartphone followed by processing with ImageJ software. The mechanism of sensing for detection and determination of Fe3+ is based on the discoloration of AgNPs which impregnated the paper substrate. The discoloration is attributed to the electron transfer reaction taking place on the surface of NPs in the presence of CTAB. Fe3+ was determined when the paper was impregnated with 1 mM AgNPs for 5 min of reaction time and the substrate was kept under acidic conditions. The linear range for determination of total iron in terms of Fe3+ was 50–900 μg L−1 with a limit of determination (LOD) of 20 μg L−1 and coefficient of variation (CV) of 3.2%. The good relative recovery of 91.3–95.0% and interference studies showed the selectivity of the method for determination of total iron in water and blood plasma samples. Smartphone–paper-based sensors have advantages of simplicity, rapidity, user-friendliness, low cost, and miniaturization of the method for on-site determination of total iron compared to methods that require sophisticated analytical instruments.

Herein, a user-friendly and portable smartphone-integrated printed-paper sensor was designed with Cu@Ag nanoparticles (NPs) for on-site monitoring of dimethoate pesticide in food samples, and the results obtained are compared with those obtained by UV-vis spectrophotometry. The working principle for identification of dimethoate pesticide is the change of yellow color NPs to reddish-yellow with associated bathochromic shift of absorption peak when pesticide introduced onto the fabricated paper or glass vial containing the NPs. A smartphone-color detector App and colorimetry were used for quantitative analysis of dimethoate in food samples. Linearity range for analysis of dimethoate using paper sensor and colorimetry were 100-2000 µgL

For the first time, functionalized asphaltene has been designed, synthesized, and used for the removal of heavy metals from the water. Asphaltene was separated from the crude oil with the addition of n-alkanes. Asphaltene having a complex chemical structure including multilayered and clustered aromatic fused rings bearing aliphatic chains. Asphaltene also contains heteroatoms like N, S, and O atoms along with Ni and V as prominent trace metals. On functionalization of asphaltene with nitric acid, the aliphatic chains and some of the naphthenic rings broke down and developed -COOH, -CO, C-O, and other oxygen functional groups which are playing key roles as surface-active agents in the removal of the heavy metals via chemisorption. The study was conducted using different parameters such as dose, time, pH, and concentration. The adsorption efficiency for this material at pH 4 is excellent for the removal of chromium and lead. The Langmuir, Freundlich and Temkin adsorption isotherm models as well as Lagergren pseudo second-order kinetic model were investigated. The positive enthalpies ΔHs confirm that the adsorption process is endothermic and the negative free energies ΔGs confirm the spontaneity of the process. The good efficiency of the adsorption implies the efficacy in the removal of the heavy metal ions, as well as the good efficiency in desorption, which implies the excellent recovery of the adsorbent. The effective reusability of this adsorbent makes it applicable for industrial water treatment from contaminants.

From the last few decades, the studies related to source apportionment of airborne particulate matter (PM) have gain more attention among global scientific community including India. The outcomes from these studies are utilized for better and effective policy design to control pollution level. However, these source apportionment results have been shown much divergence for India due to differences in sampling technique, analytical methods, selection of source maker chemical species, and application of mathematical and statistical methods, etc. So, this review presents the trends and advancement of ambient PM2.5 and PM10 particles source apportionment studies for special perspective of India for better understanding of these above highlighted issues. The ambient PM2.5 and PM10 source investigations related earlier research articles and reports from various regulatory agencies which published between the years of 2000 to 2015 for India were selected and categorized into three plateau regions for review. Few studies were carried out with source apportionment centered objectives for ambient PM2.5 and PM10 mass concentration and maximum reported studies were confined to address aerosol mass concentration and its chemical characterization to evaluate spatiotemporal variation. Higher number of data were reported for the Indo-Gangetic plain (IGP) region during the year of 2005 to 2007 with the annual average range from 56.2 to 136 μg m-3 and 134 to 306 μg m-3 for PM2.5 and PM10, respectively. The annual average for ambient PM2.5 and PM10 levels has been raised about 50 % and 14%, respectively during the first fifteen years of 21st century in Indian environment. The carbonaceous matter (TC) has been found as the major component of PM mass in Indian environment. The carbonaceous matter was reported as major abundant species which was about > 50 % of PM2.5 mass concentration with OC/EC ratio > 1. The distribution of different PM2.5 chemical components were reported to be 7 ± 15 %, 1 ± 3 %, 46 ± 49 %, 34 ± 24 % and 12 ± 9%, for crustal elements (Al, Ca, Fe, Na, Mg, Si), trace elements (Cr, Zn, Ni, Cu, Cd and Pb), ionic (Na+, NH4+, Cl−, NO3− and SO4 2−) and carbonaceous matter fractions, respectively. The following six major contributing sources for ambient PM2.5 pollution in India have been found during the assessment period i.e. road traffic emissions as the major contributor, followed by marine aerosols/sea salt, crustal, industrial emissions, secondary aerosols and biomass burning emissions.

Size-segregated aerosol samples collected from a rural site (Rajim: 20˚59′N and 81˚55′E) in eastern central India during the winter of 2011 were analyzed for anhydrosugars, sugar alcohols and primary sugars to better understand their potential sources and formation. Anhydrosugars showed the predominance of levoglucosan, whereas sugar alcohol showed the predominance of mannitol, with glucose as a major primary sugar in the sub-micron (Da 1.1 μm). Levoglucosan gave a bimodal size distribution pattern with a major peak at 0.43–0.65 μm in the sub-micron mode during period 2 and period 3, suggesting its origin from biomass burning, whereas during period 1 the major peak was found at 4.4–5.8 μm in super-micron mode that may be due to the mixing of biomass burning derived particles with soil dust particles. Sugar alcohols (arabitol and mannitol) and primary sugars (glucose and trehalose) showed bimodal size distribution trend with a major peak at 4.4–5.8 μm in super-micron mode during all periods, perhaps due to fungal activity and soil dust re-suspension, respectively. The potential ingress of biomass burning derived particles into the lungs was calculated to be high whereas fungal spores and soil particles were more likely found in the upper respiratory tract. Principal component analysis and correlation analysis showed that biomass burning was a major source in the sub-micron mode whereas fungal spores and vegetative soil were dominant sources for quantified sugars in super-micron mode.

For a better and accurate risk assessment of metal toxicity, the concentration of the bioaccessible fraction (BAF) is more relevant than the total metal concentration. This review describes different extraction methods with different leaching agents for various chemical forms of elements such as As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in ambient particulate matter (APM). Several leaching agents simulating the human body fluids have been developed to determine the bioaccessible metal fractions in APM. This study aims to enhance the knowledge of the bioaccessible concentrations and its impact on human health, documented for different locations worldwide. Furthermore, this study disclosed that confined observations have been found concerning the application and evolution of standard methods for the estimation of biologically relevant elements in ambient particulate matter. This review also revealed that human body simulated fluids like lung and gastric fluids, on comparing to water, provide more realistic values of bioaccessible fractions of potentially toxic elements (PTEs) in assessing human health risks. This study is mainly supported by SERB, India project proposal (EMR/2015/000928) and partially supported by DST FIST, India program (SR/FST/CSI-259/2014 (c)) and UGC-SAP-DRS-II, India program (F-540/7/DRS-II/2016 (SAP-I)). One of the authors, Archi Mishra (AM) is grateful to Pt. Ravishankar Shukla University for providing laboratory facilities. Carla Candeias is grateful for the support to FCT for financial support to Research Unit GeoBioTec (UID/GEO/04035/2019+UIDB/04035/2020).

We report an inkjet-printed paper based colorimetric sensor with silver nanoparticles (AgNPs) using smartphone and color detector App for on-site determination of mercuric ion (Hg

This study was carried out in Durg District of Chhattisgarh, comprising of 83 villages. It was the need for monitoring and analysis of PM2.5 to perceive the scenario and exposure of particulates over region located in rural areas of agricultural state of Chhattisgarh, dominated with anthropogenic activities related to heavy biomass fuel burning. Three rural areas, Achhoti (AC), Anjora (AN), Chandkhuri (CH) were selected and monitoring of PM2.5 and carbonaceous matter were carried out during winter and summer seasons in 2014–2015. The average seasonal variations of PM2.5 concentrations for winter and summer seasons for all sampling locations were recorded in the following order; Chandkhuri (CH) 611.37 ± 112.57 µg m−3 and 428.74 ± 80.64 µg m−3 ˃Achhoti (AC); 533.13 ± 98.5 µg m−3 and 380 ± 74.19 µg m−3 ˃ Anjora (AN); 524.36 ± 99.42 µg m−3 and 317 ± 59. 77 µg m−3, respectively. As per the annual standards given by CPCB and USEPA, the concentration of PM2.5 is higher in all sampling sites. The higher OC/EC ratio indicated the formation of secondary organic carbon (SOC), which was emitted from various primary sources. It is found in the study of high loads of fine particulates along with carbonaceous fractions purposes that it is obligatory and instant action in reduction of the emissions of carbonaceous particulates in Durg district, Chhattisgarh.

It has been posited that populations being exposed to long-term air pollution are more susceptible to COVID-19. Evidence is emerging that long-term exposure to ambient PM2.5 (particulate matter with aerodynamic diameter 2.5 μm or less) associates with higher COVID-19 mortality rates, but whether it also associates with the speed at which the disease is capable of spreading in a population is unknown. Here, we establish the association between long-term exposure to ambient PM2.5 in the United States (US) and COVID-19 basic reproduction ratio R0– a dimensionless epidemic measure of the rapidity of disease spread through a population. We inferred state-level R0 values using a state-of-the-art susceptible, exposed, infected, and recovered (SEIR) model initialized with COVID-19 epidemiological data corresponding to the period March 2–April 30. This period was characterized by a rapid surge in COVID-19 cases across the US states, implementation of strict social distancing measures, and a significant drop in outdoor air pollution. We find that an increase of 1 μg/m3 in PM2.5 levels below current national ambient air quality standards associates with an increase of 0.25 in R0 (95% CI: 0.048–0.447). A 10% increase in secondary inorganic composition, sulfate-nitrate-ammonium, in PM2.5 associates with ≈10% increase in R0 by 0.22 (95% CI: 0.083–0.352), and presence of black carbon (soot) in the ambient environment moderates this relationship. We considered several potential confounding factors in our analysis, including gaseous air pollutants and socio-economical and meteorological conditions. Our results underscore two policy implications – first, regulatory standards need to be better guided by exploring the concentration-response relationships near the lower end of the PM2.5 air quality distribution; and second, pollution regulations need to be continually enforced for combustion emissions that largely determine secondary inorganic aerosol formation., Graphical abstract Unlabelled Image, Highlights • Long-term air pollution renders a population more susceptible to COVID-19. • Exposure to PM2.5 associates with COVID-19 basic reproduction ratio (R 0) in the US. • R 0 and PM2.5 association is prominent for PM2.5 concentrations below NAAQS standard. • Secondary inorganic composition in PM2.5 impacts R 0 significantly. • Black carbon (soot) moderates the relation between secondary inorganic composition and R 0.

The review initiates with current state of information on the atmospheric reaction mechanism of biogenic volatile organic compounds (BVOCs) and its fate in the atmosphere. The plants release BVOCs, i.e., isoprene, monoterpenes, and sesquiterpenes, which form secondary organic aerosols (SOA) upon oxidation. These oxidation reactions are primarily influenced by solar radiations along with other meteorological parameters viz.; temperature and relative humidity, therefore, the chemistry behind SOA formation is different during day than the night time. The review throws light upon the day and nighttime formation mechanism of SOA, recent advancements in the analytical techniques available for the measurements, and its impact on the environment. Studies have revealed that day time SOA formation is dominated by OH and O3, however, NOx initiated SOA production is dominated during night. The formation mechanism addresses that the gaseous products of VOCs are firstly formed and then partitioned over the pre-existing particles. New particle formation and biomass-derived aerosols are found to be responsible for enhanced SOA formation. 2-Dimensional gas chromatography-mass spectrometer (2D-GC/MS) is observed to be best for the analysis of organic aerosols. Radiative forcing (RF) SOA is observed to be a useful parameter to evaluate the environmental impacts of SOA and reviewed studies have shown mean RF in the ranges of −0.27 to +0.20 W m−2.

Atmospheric PM2.5 pollution, has shown potential impact on the human health in general, thus it requires to look into the chemical characteristics of PM2.5 masses for designing effective policies to reduce health risks amongst public under exposure. The study carried out, here, has presented the ambient PM2.5 concentrations, concentrations of chemical components and associated health risks over rural and urban environments in the area of mineral based coal-fired industrial areas of central India for a period of one year (2015–16). Overall 260 PM2.5 samples, collected from rural, urban and industrial sites, were analyzed for various elements Al, As, Ca, Hg, Cr, Co, Cu, Fe, Mn, K, Cd, Mo, Ni, Pb, Se, Sb, Na, Mg, K, V and Zn, ions such as Na+, Mg2+, K+, Ca2+, F–, Cl–, NH4+, NO3–, SO42– and carbonaceous matter. The annual average PM2.5 mass concentrations were found to be ~2 to ~6 folds higher than the annual National Ambient Air Quality standard (40 µg m–3). Further this study also evaluates, carcinogenic and non-carcinogenic health risks associated with ambient PM2.5 exposures (via ingestion, inhalation and dermal). The elemental species that have shown non-carcinogenic risks for both children and adults of all three sites are: Co, Mn, Ni (rural), As, Cd, Cr, Mn, Ni, V (urban and industrial sites). Similarly, the excess carcinogenic risks, in total, from Cd, Co, Cr, Ni, Pb was found to be higher than acceptable limits (10–6 to 10–4)., Onečišćenje atmosfere lebdećim česticama (PM2.5) pokazalo je potencijalni utjecaj na zdravlje ljudi općenito. Stoga je potrebno sagledati kemijska svojstva čestica PM2.5 kako bi se postiglo učinkovito smanjenje zdravstvenih rizika izložene populacije. U ovome radu prikazuju se rezultati studije koncentracija PM2.5 i koncentracija kemijskih sastojaka u lebdećim česticama za jednogodišnje razdoblje (2015.–2016.) koji su povezani sa zdravstvenim rizicima u ruralnim i urbanim sredinama u industrijskim područjima u središnjoj Indiji u kojima se koristi mineralni ugljen kao pogonsko industrijsko gorivo. Ukupno je analizirano 260 uzoraka PM2.5 s ruralnih, urbanih i industrijskih lokacija za različite elemente: Al, As, Ca, Hg, Cr, Co, Cu, Fe, Mn, K, Cd, Mo, Ni, Pb, Se , B, Na, Mg, K, V i Zn, ione poput Na+, Mg2+, K+, Ca2+, F–, Cl–, NH4+, NO3–, SO42– i spojeve ugljika. Utvrđeno je da su prosječne godišnje masene koncentracije PM2.5 od ~2 do ~6 puta više od dopuštenih godišnjih vrijednosti prema indijskom Nacionalnom standardu kvalitete zraka (40 µgm–3). Nadalje, ova studija također ocjenjuje kancerogene i nekancerogene rizike za zdravlje povezane s izloženošću česticama PM2.5 u okolišu (putem gutanja, udisanja i dodira s kožom). Elementi koji su pokazali nekancerogene rizike i za djecu i za odrasle na sve tri lokacije su: Co, Mn, Ni (ruralno područje), As, Cd, Cr, Mn, Ni i V (urbano i industrijsko područje). Slično, utvrđen je povećan kancerogeni rizik za Cd, Co, Cr, Ni i Pb, koji je veći od prihvatljivih granica (10–6 do 10–4).

This study describes the emission factors (EFs) of 16 volatile organic compounds (VOCs) for the combustion of commonly used household solid fuels including coal balls (CB), fuelwood (FW), dung cakes (DC), crop residues (CR), and mixed fuels (MF: DC + FW), collected from ten states of India. Sum of 16 VOCs EF (g kg−1) have shown highest level (50.0 ± 22.7 g kg−1) for CB, followed by CR (23.71 ± 10.64 g kg−1), DC (19.08 ± 3.29 g kg−1), MF (15.77 ± 9.49 g kg−1), and FW (12.79 ± 5.69 g kg−1). These findings are multifold higher than those reported for biomass burning in test chamber studies. Benzene and dichloromethane EFs were found to be dominating among the aromatic and halogenated VOCs, respectively. Annual TVOCs emission estimates were evaluated to be 12.58 ± 5.92 Gg year−1 from household solid fuel burning practices. It was the 1/6th of TVOCs emission estimates (73 Gg year−1) from biomass burning in India during 2009.

To develop coarse particle (PM10-2.5, 2.5 to 10μm) chemical source profiles, real-world source sampling from four domestic cooking and seven industrial processing facilities were carried out in "Raipur-Bhilai" of Central India. Collected samples were analysed for 32 chemical species including 21 elements (Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, S, Sb, Se, V, and Zn) by atomic absorption spectrophotometry (AAS), 8 water-soluble ions (Na+, K+, Mg2+, Ca2+, Cl-, F-, NO3-, and SO42-) by ion chromatography, ammonium (NH4+) by spectrophotometry, and carbonaceous fractions (OC and EC) by thermal/optical transmittance. The carbonaceous fractions were most abundant fraction in household fuel and municipal solid waste combustion emissions while elemental species were more abundant in industrial emissions. Most of the elemental species were enriched in PM2.5 (

This study describes spatiotemporal patterns from October 2015 to September 2016 for PM2.5 mass and carbon measurements in rural (Kosmarra), urban (Raipur), and industrial (Bhilai) environments, in Chhattisgarh, Central India. Twenty-four-hour samples were acquired once every other week at the rural and industrial sites. Twelve-hour daytime and nighttime samples were acquired either a once a week or once every other week at the urban site. Each site was equipped with two portable, battery-powered, miniVol air samplers with PM2.5 inlets. Annual average PM2.5 mass concentrations were 71.8 ± 27 µg m-3 at the rural site, 133 ± 51 µg m-3 at the urban site, and 244.5 ± 63.3 µg m-3 at the industrial site, ~ 2-6 times higher than the Indian Annual National Ambient Air Quality Standard of 40 µg m-3. Average monthly nighttime PM2.5 and carbon concentrations at the urban site were consistently higher than those of daytime from November 2015 to April 2016, when temperatures were low. Annual average total carbon (TC = OC + EC) at the urban (46.8 ± 23.8 µg m-3) and industrial (98.0 ± 17.2 µg m-3) sites also exceeded the Indian PM2.5 NAAQS. TC accounted for 30-40% of PM2.5 mass. Annual average OC ranged from 17.8 ± 6.1 µg m-3 at the rural site to 64 ± 9.4 µg m-3 at the industrial site, with EC ranging from 4.51 ± 2.2 to 34.01 ± 7.8 µg m-3. The average OC/EC ratio at the industrial site (1.88) was 18% lower than that at the urban site and 52% lower than that at the rural site. OC was attributed to 43.0% of secondary organic carbon (SOC) at the rural site, twice that estimated for the urban and industrial sites. Mortality burden estimates for PM2.5 EC are 4416 and 6196 excess deaths at the urban and industrial sites, respectively, during 2015-2016.

Eight composite PM10-2.5 source profiles were developed for resuspended dust and vehicle exhaust emissions with 32 chemical species, including 21 elements (Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, S, Sb, Se, V, and Zn), 9 water-soluble ions (Na+, K+, Mg2+, Ca2+, NH4+, Cl–, F–, NO3–, and SO42–), and carbonaceous fractions (OC and EC). Dust samples were dominated by crustal elements (Al, Ca, Fe, and Mg) while exhaust emissions showed high abundances of carbonaceous aerosol (OC and EC). Crustal species (Al, Fe, Mg, and Na) were more enriched over native soils in PM10-2.5 as compared to PM2.5. The higher coefficients of divergence (COD) indicate that profiles differ from each other. Ca accounted for nearly 30% of PM10-2.5 mass in construction dust while Fe accounted for nearly 20% of PM10-2.5 mass in paved road dust. Three- and four-wheeler diesel exhaust profiles consisted of 5–7% EC, with 6–10 times higher Pb, Se, and S abundances than those in two-wheeler gasoline exhaust profile. The heavy-duty diesel exhaust profile consist of nearly 20% EC with abundant (> 0.5%) trace elements (e.g., Pb, Se, and Zn).

Dyes are major water pollutants due to their large-scale industrial applications. Dyes adversely impact both aquatic and human health. Thus, they require efficient removal from water bodies. Adsorption is an effective method for removing dyes from polluted water. In this study, we simulated the adsorption of bromophenol blue, methylene blue, and methyl orange by asphaltene and its functionalized version. Adsorption was simulated using molecular dynamics (MD) and density functional theory (DFT) calculations. Our results indicated that functionalized and nonfunctionalized dyes have varying interaction energies depending on the nature of the dye. MD simulations indicated that methylene blue tends to have a stronger interaction with asphaltene than the other dyes. Methyl orange bound more strongly with the functionalized asphaltene (FASP) than with the other dyes. Bromophenol blue dye demonstrated weak interaction with both types of asphaltene. DFT calculations were conducted to understand the nature and strength of the interactions between the dyes and asphaltene. In this study, we also analyzed binding energy, electrostatic potential, frontier molecular orbitals, and noncovalent interactions. The DFT and MD analyses supported the experimental finding that FASP is a better adsorbent of dyes than nonfunctionalized asphaltene.

In South Asia, combustion of solid fuel for residential heating and cooking is a major emission source of particulate-phase polycyclic aromatic hydrocarbons (p-PAHs), a potent carcinogen for human health. The emission factors (EFs) and source diagnostic ratios of PAHs currently used in regional inventory models have been estimated from controlled laboratory tests, which do not accurately reflect real-world combustion scenarios observed in rural Indian households. Consequently, the health effects associated with p-PAH levels in indoor and ambient air could be severely underestimated and undervalued. We performed a nationwide study across ten different states in the Indian subcontinent to evaluate the EFs and source diagnostic ratios of sixteen U.S. Environmental Protection Agency (EPA) identified high priority p-PAHs emitted from residential solid biomass combustion. Our estimated average annual EFs were 2.4–18.3 fold higher than those reported from previous laboratory-based investigations. Carcinogenic toxicity analysis shows that combustion of dung cake and coal ball, both widely used residential solid fuels, posed the most risk (80% and 59% respectively) in comparison to other PAHs owing to predominant emission of benzo[a]pyrene. Our findings underscore the importance of improved laboratory testing and field validations as crucial steps toward more accurate emission inventories and better assessment of public health impacts.

Concentrations of trace elements (Al, B, As, Be, Cd, Ba, Co, Cu, Fe, Cr, Sb, Ni, Li, Sn, Mn, Zn, V and Se) were determined in 160 groundwater samples, collected during pre-monsoon (PRM) and post-monsoon (POM) period (2017) in the tribal belt of Bastar, central India, using inductive coupled plasma mass spectrometry (ICP-MS). The concentrations of Al, As, Fe, Mn and Ni were found exceeding the permissible limits in 49% of samples. Cd, Sn and Se elements have shown two-fold increment in POM samples than those collected during PRM. On the contrary, Al, Ba, Co, Cr and Fe have shown a declining trend from PRM to POM period. On applying Principal component analysis (PCA) and Positive matrix factorization (PMF) approaches to the dataset, observed three primary sources (natural, geogenic and agricultural) for groundwater elemental components. Among the measured potentially toxic elements (PTEs), As has shown higher carcinogenic and non-carcinogenic risk in children as well as adults This study recommends the regular monitoring of heavy metal contamination of groundwater as various geogenic and anthropogenic activities may elevate the risk of severe health hazards.

We report an inkjet-printed paper based colorimetric sensor with silver nanoparticles (AgNPs) using smartphone and color detector App for on-site determination of mercuric ion (Hg2+) from environmental water samples. The AgNPs printed on Whatman filter paper (No. 1) is employed for detection of Hg2+ which is reliant on the color change of NPs from yellow to discoloration depending on the concentration of target analyte in sample solution. The quantitative determination was performed by calculating the signal intensity of AgNPs on printed paper substrate after the introduction of Hg2+ using smartphone and RGB color detector. The mechanism for detection of Hg2+ on paper substrate is verified using UV-Vis spectrophotometry (UV-Vis), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS) and basic chemical assays. The linear range acquired for paper based colorimetric detection in the range of 40–1200 µgL−1 with limit of detection of 10 µgL−1. The results obtained using an inkjet-printed paper-based chemical sensor combined with a smartphone is validated with data of inductively coupled plasma-atomic emission spectroscopy (ICP-AES) measurement. The advantages of paper based detection are simple, rapid, economic and can be applied at the sample sources for determination of Hg2+.

Residential solid biomass cookstoves are important sources of aerosol emissions in India. Cookstove emissions rates are largely based on laboratory experiments conducted using the standard water-boiling test, but real-world emissions are often higher owing to different stove designs, fuels, and cooking methods. Constraining mass emissions factors (EFs) for prevalent cookstoves is important because they serve as inputs to bottom-up emissions inventories used to evaluate health and climate impacts. Real-world EFs were measured during winter 2015 for a traditional cookstove (chulha) burning fuel wood, agricultural residue, and dung from different regions of India. Average (±95 % confidence interval) EFs for fuel wood, agricultural residue, and dung were (1) PM2.5 mass: 10.5 (7.7–13.4) g kg−1, 11.1 (7.7–15.5) g kg−1, and 22.6 (14.9–32.9) g kg−1, respectively; (2) elemental carbon (EC): 0.9 (0.6–1.4) g kg−1, 1.6 (0.6–3.0) g kg−1, and 1.0 (0.4–2.0) g kg−1, respectively; and (3) organic carbon (OC): 4.9 (3.2–7.1) g kg−1, 7.0 (3.5–12.5) g kg−1, and 12.9 (4.2–15.01) g kg−1, respectively. The mean (±95 % confidence interval) OC ∕ EC mass ratios were 6.5 (4.5–9.1), 7.6 (4.4–12.2), and 12.7 (6.5–23.3), respectively, with OC and EC quantified by the IMPROVE_A thermal-optical reflectance protocol. These real-world EFs are higher than those from previous laboratory-based measurements. Combustion conditions have larger effects on EFs than the fuel types. We also report the carbon mass fractions of our aerosol samples determined using the thermal-optical reflectance method. The mass fraction profiles are consistent between the three fuel categories but markedly different from those reported in past literature – including the source profiles for wood stove PM2.5 emissions developed as inputs to receptor modeling studies conducted by the Central Pollution Control Board of India. Thermally stable OC (OC3 in the IMPROVE_A protocol) contributed nearly 50 % of the total carbon mass for emissions from all fuels.

Many households use solid fuels for cooking and heating purposes. There is currently a knowledge gap in our understanding of the variations in indoor air quality throughout the household as most of the studies focus on the areas in the close proximity of the cookstove. A low-cost wireless particulate matter (PM) sensor network was developed and deployed in households in Raipur, India to establish the spatio-temporal variation of PM concentrations. The data from multiple sensors were acquired in real-time with a wireless system. Data collected from the sensors agreed well (R2 =0.713) with the reference data collected from a commercially available instrument. Low spatial variability was observed within the kitchen due to its small size and poor ventilation - a common feature of most rural Indian kitchens. Due to insufficient ventilation from open doors and windows, high PM concentrations similar to those found in the kitchen were also found in the adjoining rooms. The same household showed significantly different post-extinguished cookstove PM concentration decay rates (0.26mg/m3-min and 0.87mg/m3-min) on different days, owing to varying natural air exchange rates (7.68m3/min and 37.40m3/min).

Laboratory experiments were performed to examine the combined toxic effects of two important aquatic contaminants viz., arsenic and fluoride on African catfish, Clarias gariepinus. Additionally, the bio concentration factors (BCFs) of the two contaminants in tissues and blood of catfish were also determined. The LC50 for sodium fluoride and arsenic trioxide were determined to be 619.3 mg L-1, 30.3 mg L-1, respectively. Erratic swimming movements with hyperactivity, loss of equilibrium, augmented air gulping and decreased food consumption were observed in the experimental groups. In co-exposure groups of arsenic and fluoride, the concentration of fluoride in fish tissues increased with increasing water fluoride concentration in the test aquaria with significant differences (P 0.05) among the exposure groups. Arsenic was observed to exceedingly bioaccumulate and biomagnify in the tissues. Perhaps due to the complex formation of arsenic and fluoride the bio concentration of arsenic in tissues was observed to decrease with increasing water fluoride concentration and vice-versa. The study concludes that fluoride may interfere with the bio-concentration of arsenic.

Samples of rainwater (RW) were collected to characterize the chemistry and sources in two representative megacities at Pune (Southwest) and Delhi (Northern) India from 2011 to 2014 across two seasons: monsoon (MN) and non-monsoon (NMN). Collected RW samples were analyzed for major chemical constituents (F−, Cl−, SO42−, NO3−, NH4+, Na+, K+, Ca2+, and Mg2+), pH and conductivity. In addition, bicarbonate (HCO3−) was also estimated. The mean pH values of the RW were >6 at Pune and

The use of L-cysteine modified silver nanoparticles (Cys-capped AgNPs) as a colorimetric probe for determination of vitamin B1 (thiamine) is described in the present work. This method is based on the measurement of red shift of localized surface plasmon resonance (LSPR) band of Cys-capped AgNPs in the region of 200–800 nm. The color of Cys-capped AgNPs was changed from yellow to colorless by the addition of vitamin B1. The mechanism for detection of vitamin B1 is based on the electrostatic interaction between positively charged vitamin B1, which causes the red shift of LSPR band from 390 nm to 580 nm. The interaction between Cys-capped AgNPs and vitamin B1 was theoretically explored by density function theory (DFT) using LANL2DZ basis sets with help of Gaussian 09 (C.01) program. The morphology, size distribution and optical properties of Cys-capped AgNPs were characterized by transmission electron microscope (TEM), UV-Visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS) techniques. The method is linear in the range of 25–500 μg mL−1 with correlation coefficient (R2) 0.992 and limit of detection of 7.0 μg mL−1. The advantages of using Cys-capped AgNPs as a chemical sensor in colorimetry assay are being simple, low cost and selective for detection of vitamin B1 from food (peas, grapes and tomato) and environmental (river, sewage and pond) water samples., Food science; Environmental science, Materials chemistry, Cys-capped silver nanoparticles; Electrostatic interaction; Aggregation, Colorimetric probe; Vitamin B1; Food and environmental water samples

It has been posited that populations being exposed to long-term air pollution are more susceptible to COVID-19. Evidence is emerging that long-term exposure to ambient PM2.5 (particulate matter with aerodynamic diameter 2.5 μm or less) associates with higher COVID-19 mortality rates, but whether it also associates with the speed at which the disease is capable of spreading in a population is unknown. Here, we establish the association between long-term exposure to ambient PM2.5 in the United States (US) and COVID-19 basic reproduction ratio R0– a dimensionless epidemic measure of the rapidity of disease spread through a population. We inferred state-level R0 values using a state-of-the-art susceptible, exposed, infected, and recovered (SEIR) model initialized with COVID-19 epidemiological data corresponding to the period March 2–April 30. This period was characterized by a rapid surge in COVID-19 cases across the US states, implementation of strict social distancing measures, and a significant drop in outdoor air pollution. We find that an increase of 1 μg/m3 in PM2.5 levels below current national ambient air quality standards associates with an increase of 0.25 in R0 (95% CI: 0.048–0.447). A 10% increase in secondary inorganic composition, sulfate-nitrate-ammonium, in PM2.5 associates with ≈10% increase in R0 by 0.22 (95% CI: 0.083–0.352), and presence of black carbon (soot) in the ambient environment moderates this relationship. We considered several potential confounding factors in our analysis, including gaseous air pollutants and socio-economical and meteorological conditions. Our results underscore two policy implications – first, regulatory standards need to be better guided by exploring the concentration-response relationships near the lower end of the PM2.5 air quality distribution; and second, pollution regulations need to be continually enforced for combustion emissions that largely determine secondary inorganic aerosol formation.

USEPA’s UNMIX, positive matrix factorization (PMF) and effective variance-chemical mass balance (EV-CMB) receptor models were applied to chemically speciated profiles of 125 indoor PM2.5 measurements, sampled longitudinally during 2012–2013 in low-income group households of Central India which uses solid fuels for cooking practices. Three step source apportionment studies were carried out to generate more confident source characterization. Firstly, UNMIX6.0 extracted initial number of source factors, which were used to execute PMF5.0 to extract source-factor profiles in second step. Finally, factor analog locally derived source profiles were supplemented to EV-CMB8.2 with indoor receptor PM2.5 chemical profile to evaluate source contribution estimates (SCEs). The results of combined use of three receptor models clearly describe that UNMIX and PMF are useful tool to extract types of source categories within small receptor dataset and EV-CMB can pick those locally derived source profiles for source apportionment which are analog to PMF-extracted source categories. The source apportionment results have also shown three fold higher relative contribution of solid fuel burning emissions to indoor PM2.5 compared to those measurements reported for normal households with LPG stoves. The previously reported influential source marker species were found to be comparatively similar to those extracted from PMF fingerprint plots. The comparison between PMF and CMB SCEs results were also found to be qualitatively similar. The performance fit measures of all three receptor models were cross-verified and validated and support each other to gain confidence in source apportionment results.

A simple and convenient assay based on single-drop microextraction with infrared spectroscopy is reported for the determination of selenium. The extraction conditions were carefully optimized and selenium was preconcentrated through single-drop microextraction in 1,2-dichloroethane containing N-hydroxy-N-phenyl-N′-(o-tolyl) benzimidamide. The method is selective and almost all common ions including molybdenum(VI), chromium(VI), and tungsten(VI) did not interfere with the isolation protocol. The selenite band at 875 ± 2 cm−1, which is assigned to the asymmetric vibrational stretch (υ3), was used for the quantification of selenium. Low limits of detection and quantification of 2.0 and 6.6 µg L−1 demonstrate the sensitivity of the method. Good precision was evaluated by the standard deviation (2.0 µg L−1) and relative standard deviation (0.5%) for 8 µg L−1 was achieved for 10 measurements. The method was used to analyze human blood, urine, and water for selenium.

PM2.5 concentrations were measured in residential indoor environment in slums of central India during 2012–2013. In addition, a suite of chemical components including metals (Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb, Mo, Se, Sb, Na, Mg, K and Hg), ions (Na+, Mg2+, K+, Ca2+, F−, Cl−, NH4 +, NO3 − and SO4 2−) and carbon (OC and EC) were analyzed for all samples. Indoor PM2.5 concentrations were found to be several folds higher than the 24-h national ambient air quality standard (60 µg/m3) for PM2.5 in India, and the concentrations were found to vary from season to season. Mass closure was attempted for PM2.5 data, and close to 100 % mass was accounted for by organic matter, crustal material, secondary organic and inorganic aerosols and elemental carbon. Additionally, carcinogenic and non-carcinogenic health risks associated with exposure to indoor PM2.5 (inhalation, dermal and ingestion) were estimated and while exposures associated with dermal contact and ingestion were found to be within the acceptable limits, risk associated with inhalation exposure was found to be high for children and adults. Elements including Al, Cd, Co, Cr, Mn, Ni, As and Pb were present in high concentrations and contributed to carcinogenic and non-carcinogenic risks for residents’ health. Results from this study highlight the need for efforts to reduce air pollution exposure in slum areas.

The study was carried out to evaluate the seasonal and annual trend of thermal fractions (organic and elemental carbon) associated to different cultural/ritual-indoor aerosol carbonaceous matter compared to residential-indoors and ambient-outdoors. Thermal speciation of carbonaceous fractions (SCFs: OC1, OC2, OC3, OC4, OP, EC1, EC2, EC3) associated to cultural/ritual-indoors and indoor/outdoor relationship were also taken into account in four different types of cultural/ritual centers: 1) Marriage Places (MP), 2) Muslim Holy Shrines (MHS), 3) Buddhist Temples (BT), and 4) Hindu Temples (HT). Longitudinally measured 360 PM2.5/PM10 samples throughout the year 2012–13, onto quartz fiber filters, were analyzed for organic (OC) and elemental carbon (EC) alongwith eight SCFs using thermal/optical reflectance/transmittance method. SCFs were determined in selected samples, representing all selected cultural/ritual-indoors, to address the source markers associated to biomass burning (BB) emissions; observed during cultural/ritual performances. Results have shown significantly higher levels of BB markers' SCFs in cultural/ritual-indoors compared those reported for residential-indoors and ambient-outdoors. Three to eight-fold higher carbonaceous aerosols was found in cultural/ritual-indoors compared to those determined in residential-indoors and ambient-outdoors. OC/EC ratio was found 2-fold higher in MHS and MP places compared to those found in other selected indoor and outdoor sites. Similarly, higher degree of seasonal variability with higher occurrence of aerosol fractions and associated OC and EC in winter is observed in both MHS and MP due to higher activity pattern.

Previous studies, including ours, have shown adverse effects of incense smoke on human health. However, the effect of incense smoke on kidney function and structure remains unknown.To evaluate possible adverse effects of incense smoke on kidney function and architecture in albino rats after chronic exposure to Arabian incense.Emission characteristics including particle size distribution, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) were determined by gravimetric and GCMS analyses. Kidney functional markers, oxidative stress and inflammatory markers were measured by standard or ELISA based procedures. Ultrastructural changes in kidney were examined by transmission electron microscope (TEM) and the gene expression of xenobiotic metabolizing enzymes including cytochrome P-450-1A1 (CYP1A1) and CYP1A2 were studied by real time PCR.Rats exposed to incense smoke demonstrated a significant increase in serum creatinine, uric acid, blood urea nitrogen (BUN), tissue malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α) and interleukin-4 (IL-4) levels and a significant decline in tissue reduced glutathione (GSH) and catalase activity. Incense smoke exposed rats also displayed marked ultrastructural changes in kidney tissue. Further, a significant increase in tissue gene expression of both CYP1A1 and CYP1A2 was noted in exposed rats.Changes to kidney functional markers and architecture appear to be mediated through augmented oxidative stress and inflammation.Long-term exposure to incense smoke may have deleterious effects on kidney function and architecture. Though, inhalation is the rout of exposure, findings of this study underscore that incense smoke may also have an effect on non-pulmonary tissues.

Ambient PM 2.5 (particulate matter less than 2.5 μm) samples, collected in a 8-week wintertime sampling program in two residential sites of Bhilai, India during the Indian Diwali festival in November 2012, were chemically characterized for 38 chemical species including eight speciated carbonaceous fractions (SCFs) of elemental (EC) and organic carbon (OC), twenty one metallic elements, and nine water soluble ionic species. Our objectives were to investigate: 1) relative abundances of SCFs contained in PM 2.5 during the Diwali festival period compared to normal days, and 2) enrichment pattern of potential inorganic markers of firework emission in ambient PM 2.5 during the festival days. Eight-fold increase inPM 2.5 mass concentrations were measured during the Diwali festival days compared to concentrations occurring in normal days. Bursting of firecrackers in the residential streets have shown significant contribution to the emission markers (K, Mg, Zn, S, EC and OC) along with crustal markers (Ca, Fe, Al) in ambient PM 2.5 aerosol samples. Concentrations of water soluble ionic species were found to be 10 times greater than those found in normal days. Further, the anion/cation ratios were found to reach a factor of 2; indicating the acidic character of emissions resulting from fireworks. The relative abundance of SCFs and higher ratios of OC to EC during the Diwali episode suggested the significant formation of secondary organic carbon (SOC) aerosols. We estimate that aerosols emitted from firework bursting contribute up to 32% of total ambient PM 2.5 during the Diwali festival.

The spreading of fluorosis diseases in Central India related to high concentrations of fluoride ion (F−) is a cause of major concern. In this work, the hydrochemistry of the aquifers related to Seonath River, in Rajnandgaon district, Chhattisgarh state, India, has been studied, focusing on the presence and sources of F−. Hydrochemical parameters were analyzed in the post-monsoon season in 160 wells located in nine tehsils, finding F− concentrations ranging from 0.6 to 18.5 mg L−1. Seasonal variations were also studied in Chhuikhadan tehsil, in which the highest F− values were registered, finding a noticeable enrichment in the pre-monsoon months. In many locations of the district, F− concentrations exceeded the recommended value of 1.5 mg L−1, which have led to the appearance of several health issues. Multidimensional analysis statistical methods were adopted to investigate the sources of F−, and the mineralization of bedrock elements into the groundwater was observed to be the primary source.

This study illustrates the spatiotemporal variability pattern and source-routes of major ionic contaminants of groundwater in mineral-rich tribal belt of Bastar, India. Around 160 groundwater samples from 95 sampling sites were collected during the pre- and post-monsoon periods using a pooled study design. These samples were then chemically analyzed for pH, TDS, EC, TH, Mg2+, Ca2+, Na+, K+, HCO3−, F−, NO3−, Cl−, and SO42−. Ionic species exhibited distinct spatial variability patterns at the temporal scale of pre- and post-monsoon periods. Two source apportionment modeling techniques (PCA and PMF 5.0), based on factor analysis, were applied to investigate the source-routes of ionic components in groundwater. Three major contributing source-routes were identified for the ionic components: 1) mineral dissolution (~25%), 2) agricultural activities (30–36%), and 3) rainwater percolation (40–45%). The suitability of groundwater for irrigation purposes was also evaluated by analyzing the electrical conductivity, sodium percentage, and sodium adsorption ratio. The study will serve as an important reference for understanding groundwater chemistry and improving sustainable groundwater management planning in the tribal belt of the Bastar region.

Emission factors (EFs) of PM2.5, carbon fractions, major ionic (K+, Ca2+, NH4+, SO42−, NO3− and Cl−) and elemental (Al, Cr, Cu and Fe) species from combustion of commonly used household solid fuel were determined in 10 different states in India during cooking practices. The study involved sampling during actual household cooking involving use of a variety of fuels including coal balls (CB), fuel wood (FW), dung cakes (DC), crop residues (CR), mixed fuels (MF: dung cakes + fuel woods). Species-wise highest EFs (g·kg−1) were: 34.16 ± 10.1 for PM2.5 (CB), 14.18 ± 5.8 for OC (CB), 2.33 ± 1.4 for EC (DC), 1.03 ± 0.2 for K+ (CR), 2.21 ± 0.6 NH4+ (DC), 0.61 ± 0.2 for NO3− (CB), 0.59 ± 0.1 for SO42− (CB), 0.69 ± 0.1 for Cl− (CR) among the fuels. Higher OC EFs for CB could be attributed to higher moisture content (>13%) in coal-powder that is used to handmade coal balls. It is observed that, in general, OC3 and EC1 were the dominant thermally evolved carbon mass fractions. The study averaged MCE values were in the range 0.93–0.98, which could be attributed to higher variability in flaming and smoldering episodes during the combustion of selected fuels. Sum of ionic EFs for emissions from DC, CR and MF were found to be higher than those observed for FW and CB. The K+/EC and Cl−/EC (~1) ratios could be better indicators of CR fuels to differentiate it from FW, whereas NH4+/EC (~1) is suitable to indicate DC. Average annual emission estimates of PM2.5 (2.00 ± 0.53 Tg·yr−1), OC (0.86 ± 0.23 Tg·yr−1) and EC (0.11 ± 0.02 Tg·yr−1) for tested fuels are evaluated to be contributing 27, 15 and 4% of total PM2.5, OC and EC, respectively, toward annual emission budget from different anthropogenic activities in India.