Open Burning Of Waste Research Articles

Managing Solid Waste at Isabela State University Cabagan (ISUC) Campus: Current Practices and Unfolding Opportunities

Solid waste is a pressing environmental concern nowadays. Even academic institutions are not exempted on its associated problems. To this end, the practices and implementation schemes of ISUC in addressing the concerns on solid wastes were assessed. Through individual interviews, actual field observations/validations, and desk review of documents, several qualitative data were generated categorized, summarized and analyzed through content analysis. Results show that in so far as solid waste and its management is concern, the following key issues/concerns were identified: absence of an approved long-term SWM Plan; source of funding support for SWM programs; lack of manpower in implementing the SWM programs; no segregation/reduction of wastes at source; collection system needs to be revisited/changed; open burning and littering of wastes; recovery facilities need improvement; functionality of SWM equipment; and IEC campaign materials. In terms of SWM initiatives, the campus has existing institutional arrangements on dealing with solid wastes concerns. It also has various equipment and manpower to cater the needs for SWM. Source reduction and segregation-at-source are also given attention including collection system but not fully functional/operational. There are also existing recycling initiatives and marketing of recyclables/saleable materials. As to disposal, the special/hazardous wastes from laboratory and health offices are stored in the septic vault beside the campus’ Centralized Materials Recovery Facility. In addition, scientific studies were conducted vis-à-vis SWM. However, complementary activities need to be made in place which include: strengthening IEC campaigns; attendance to SWM capacity-building programs; and the adoption of a comprehensive campus-based SWM Framework

A Clinical Study to Evaluate the Efficacy of Haridrakhanda in the Management of Allergic Rhinitis in Paediatric Age Group

Increased levels of environmental pollution, especially air pollution due to industrialization, increased vehicles, re-suspended dust on roads due to vehicle movement and construction activities, open waste burning, combustion of various fuels and also seasonal influences from dust storms, forest fires, open field fires during harvest season, sea salt near coastal areas and decreased immunity due to factors like lifestyle modifications, food habits and climatic variations leads to innumerable health hazards. Among those one such condition is Vataja Pratishyaya with a similar clinical entity with that of allergic rhinitis. Allergy is a condition in which the immune system reacts abnormally to a foreign substance. ‘Allergic rhinitis’ is characterized by inflammatory changes in the nasal mucosa caused by exposure to inhaled allergens. This is highly prevalent and common disease to the extent that 30% of the total diseases and around 20-30% of the Indian population suffers from the same. Allergic rhinitis is associated with number of co morbid conditions such as asthma, sinusitis, otitis media, atopic dermatitis and nasal polyps. The condition shows immediate hypersensitivity reaction of Nasal mucosa to allergens like pollen, dust, strong perfumes, smoke and cold climate. Pratishyaya is well known for its re-occurrence and chronicity. In this study Haridrakhanda was given internally for the management of Allergic rhinitis in children of 6 to 14 years of age group. Milk was given as anupana by considering the properties of drugs in the formulation and palatability in children. Subjective and objective parameters [according to ‘Total Nasal symptom score’, North West ENT and Allergy] were assessed and the results obtained were statistically significant.

Replacing the greater evil: Can legalizing decentralized waste burning in improved devices reduce waste burning emissions for improved air quality?

Open waste burning emissions constitute a significant source of air pollution affecting human health in India. In regions where cleaner fuels have displaced solid biofuel usage, open waste burning is rapidly becoming one of the largest sources of airborne human class-I-carcinogens and particulate matter. As the establishment of waste management infrastructure in rural India is likely to take years, we explore whether health-relevant emissions can be reduced by legalizing the burning of dry non-biodegradable waste in improved devices. We measure the emission factors of 76 VOCs, CH4, CO, and CO2 from different types of waste burned in two different improved devices, a burn basket and a local water heater. Based on our experiments, we create four “what-if” intervention scenarios to assess the improvement of air quality due to the emission reductions that can be accomplished by four management strategies. We find that substituting the traditional, more polluting water heating fuels with dry plastic waste across rural India can reduce primary emissions (e.g., −29 Ggy−1 for benzene) and ozone formation potential (−2960 Ggy−1) from open waste burning. When dry waste is used in lieu of more polluting fuels, and its burning serves a purpose, the net class-I-carcinogen benzene emissions, would be halved compared to the present. The change in emissions for the class-I carcinogen 1,3-butadiene would become net negative. This happens because the emissions avoided when part of the solid biofuel currently used in rural India is replaced by plastic waste (4.1 (1.2–4.1) Ggy−1) exceed the waste burning emissions of this compound (3 (1.2–3.7) Ggy−1) by so much, that residential sector emission reductions offset all waste burning emissions including those of landfill fires. Our study demonstrates that India's air quality can be improved by permitting and promoting the use of dry packaging waste in lieu of traditional biofuels and by promoting improved burning devices.

Phytotoxicity of particulate matter from controlled burning of different plastic waste types

According to careful estimations, open burning of plastic waste affects app. 2 billion people worldwide. While human health risks have become more and more obvious, much less information is available on the phytotoxicity of these emissions. In our study phytotoxicity of particulate matter samples generated during controlled combustion of different plastic waste types such as polyvinyl chloride (PVC), polyurethane (PUR), polypropylene (PP), polystyrene (PS) and polyethylene (PE) was evaluated based on peroxidase levels. While different samples showed different concentration-effect relationship patterns, higher concentration(s) caused decreased peroxidase activities in each sample indicating serious damage.

Tropical Air Chemistry in Lagos, Nigeria

The Nigerian city of Lagos experiences severe air pollution as a result of emissions and subsequent atmospheric photochemistry and aerosol chemistry. A year-long study, between August 2020 and July 2021, included measurements of gas-phase and aerosol processes, with surface meteorology at six urban sites. The sites were selected to represent near seacoast conditions, urban sites, and inland locations near agricultural and grassland ecosystems. The observations included continuous concentrations for CO, SO2, NOx, O3, PM2.5, and PM10. Samples were collected and analyzed for speciated volatile organic compounds (VOCs) and particulate chemical composition including inorganic and organic chemical species. The average diel variations in concentrations indicated well-known local photochemistry resulting from the presence of combustion sources, including motor vehicles, petroleum production and use, and open burning. The annual diel characteristics were emission-dependent and were modulated by meteorological variability, including the sea breeze and the seasonal changes associated with monsoons and Harmattan winds. Gases and particulate matter varied daily, consistent with the onset of source activities during the day. Fine particles less than 2.5 μm in diameter (PM2.5) included both primary particles from emission sources and secondary particles produced in the atmosphere by photochemical reactions. Importantly, particle sources included a large component of dust and carbonaceous material. For the latter, there was evidence that particle concentrations were dominated by primary sources, with little secondary material formed in the atmosphere. From complementary measurements, there were occasions when regional chemical processes affected the local conditions, including transportation, industry, commercial activity, and open waste burning.

Stabilization of Red Clay Soil using Rice Straw

Abstract: Infrastructure projects such as highways, railways, water reservoirs etc, requires earth materials in very large quantities. The foundation should have sufficient strength to support any land based structure. The soil surrounding the foundation plays a very important role. The strength of soil should be maintained according to the loading conditions. One of the most important aspect for construction purpose is to improve the soil strength i.e; stabilizing soil. Here, in this paper, soil stabilization is done by mixing of soil with the chemical treated rice straws fibers. The main motive of this analysis is to find out the utilization of waste rice straw fiber materials in foundation construction without open burning of waste so we can reduce the pollution which create by the open burning of rice straw in the fields.

Compilation of a city-scale black carbon emission inventory: Challenges in developing countries based on a case study in Brazil

Black carbon (BC) inventories for cities are scarce, especially in developing countries, despite their importance to tackle climate change and local air pollution. Here, we draw on results from a case study in a Brazilian city to discuss the challenges of compiling a BC inventory for different activity sectors. We included traditionally inventoried sectors, such as industries and on-road transportation, other less reported sectors (food establishments and aviation), and open burning of household solid waste (HSW), typically found in developing countries. We present a machine-learning technique (Random Forest) as a novel approach to obtain HSW burning activity using a set of spatial predictors. The BC inventory was based on PM2.5 emissions weighted by the fraction of PM2.5 emitted as BC and developed for the year 2018. We also reported the disaggregated spatial PM2.5 emissions for the same combustion sources, and documented the databases used for activity data and emission factors (EF). The total estimated BC and PM2.5 emissions amounted to 57.88 and 234.75 tons, respectively, with on-road vehicle exhaust emissions and industrial combustion as the main BC sources (63 and 22%, respectively). For PM2.5 emissions, on-road transportation (exhaust and non-exhaust) contributed 48%, followed by industrial combustion (21%) and food establishments (20%). Population density, number of vacant lots, and property tax values were identified as the most important features to predict the HSW fire activity. A comparison with other inventories revealed that the BC emission profile of Londrina is similar to the profile reported for Greater Mexico City, another Latin American city. Thus, the methodology used in this study could be extended to other cities with similar local BC sources. Finally, we highlight that the lack of local activity data, representative EF, and even methodology may undermine the development of reliable BC inventories, and intensive research should be conducted to characterize the emission sources.

A comprehensive review of domestic-open waste burning: recent trends, methodology comparison, and factors assessment.

Open burning is a waste management practice performed by many people worldwide, especially in developing countries. Lack of detailed data of open burning practices may lead to a misinterpretation during data analysis, especially when estimating global/local emissions and assessing risks. This study presents a comprehensive review of current research trends, methodological assessments, and factors behind open waste burning practices from published literature. This review used systematic methods such as PRISMA 2020 methodology, a bibliometric approach, and qualitative content analysis to determine and assess 84 articles related to open burning. The results show that environmental risks and emission factors related to open burning incidents at the landfill or residential level are preferable topics that will be rising in the years to come. Coupling methods such as a transect-based approach with a questionnaire survey and mobile-static plume sampling to determine the activities and incidents as baseline data for risk assessment will help researchers gain a robust dataset of open burning emission inventory. In addition, it was found that environmental knowledge and awareness levels influence open burning practices, thereby opening up opportunities for future research.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10163-022-01430-9.

Waste leachate induces histological alterations in Limicolaria aurora (Jay, 1839) digestive gland

Unsanitary open dumping and burning of wastes in dumpsites results to constant leaching of waste pollutants into the surrounding environment with attendant harmful consequences on wildlife and public health. Here, we investigated the histological effects of Onitsha municipal waste leachate on the Giant African land snail, Limicolaria aurora (Jay 1839). The histopathological effects of waste leachate on the digestive cells of the snails were examined following standard protocols. Snails were exposed to different concentrations (0, 6.25, 12.5, 25.0 and 50.0%) of the leachate for a total duration of 21 days. Histological results obtained showed that waste leachate caused dose and duration dependent alterations in the digestive glands of L. aurora. Obvious histological variations were observed in snails exposed to 50% concentrations of the leachate compared to other doses. Observed histological changes were mainly degeneration of the digestive tubules, fragmentation and disappearance of the digestive cells, marked increase in excretory cells, necrosis and epithelia sloughing. This study therefore highlights the potential toxicity of waste leachate of causing mild to severe damage in the tissues of organisms. Reinforcing the fact, that waste leachate contains a mix of toxic substances that could pose a severe injury to the biological system of surrounding biota, including humans.

Validating the 6 year (2016–2021) anthropogenic induced small island wildfire hazards in Pulau Seribu archipelago, Indonesia

Due to their specific characteristics, small islands tend to face unique challenges, including the challenges posed by wildfire threats caused by the presence of volatile vegetations and anthropogenic influences. This study aims to validate the impacts of the anthropogenic influence on wildfire risks for the period of 2011–2021 in several occupied small islands in Pulau Seribu archipelago, including Tidung and Pari Islands. An uninhabited island, Tidung Kecil Island, was used as control. To validate the anthropogenic influences on wildfire presences, the ANOVA one-way and Receiver Operating Characteristic (ROC) methods were used. Results show that human occupancy has significantly contributed to the wildfire frequency and burnt area size (F = 4.413, p = 0.001), with the occupied islands have the highest wildfire frequencies of 0.45 cases annually, and the highest burn area average of 4076 m2 annually. The uninhabited island only experiences 0.09 wildfires per year. Wildfires occur both day and night. Daytime wildfires were mostly caused by improper disposal of cigarette butts or smoking activities. In contrast, nighttime wildfires were caused by open waste burning and camping activities.The validation using the ROC, with an area under the ROC curve value (AUC) of 0.671 (95%CI: 0.301–1), has validated the accuracy that the anthropogenic factors are proxies for wildfire hazards in Tidung Island. However, the accuracy of the anthropogenic influence-wildfire hazard association in Pari Island is slightly lower with an AUC of 0.633 (95%CI: 0.321–0.946). These confirm the potential of anthropogenic influences as a proxy for wildfire, especially in Tidung Island.

Global Emissions of Hydrogen Chloride and Particulate Chloride from Continental Sources.

Gaseous and particulate chlorine species play an important role in modulating tropospheric oxidation capacity, aerosol water uptake, visibility degradation, and human health. The lack of recent global continental chlorine emissions has hindered modeling studies of the role of chlorine in the atmosphere. Here, we develop a comprehensive global emission inventory of gaseous HCl and particulate Cl- (pCl), including 35 sources categorized in six source sectors based on published up-to-date activity data and emission factors. These emissions are gridded at a spatial resolution of 0.1° × 0.1° for the years 1960 to 2014. The estimated emissions of HCl and pCl in 2014 are 2354 (1661-3201) and 2321 (930-3264) Gg Cl a-1, respectively. Emissions of HCl are mostly from open waste burning (38%), open biomass burning (19%), energy (19%), and residential (13%) sectors, and the major sources classified by fuel type are combustion of waste (43%), biomass (32%), and coal (25%). Emissions of pCl are mostly from biofuel (29%) and open biomass burning processes (44%). The sectoral and spatial distributions of HCl and pCl emissions are very heterogeneous along the study period, and the temporal trends are mainly driven by the changes in emission factors, energy intensity, economy, and population.

Activity and emission inventory of open waste burning at the household level in developing countries: a case study of Semarang City.

In this study, total burned household waste and the potential emissions released from waste burning in Semarang City, Indonesia, were estimated. Waste piles were monitored using the transect walk survey method in 16 sub-districts of Semarang City. Carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC), nitrous oxide (NOx), and total particulate matter (TPM) were directly analyzed through a simulation of waste combustion. The potential emissions from other pollutants were predicted by multiplying the weight of the burned waste by the emission factors available in the literature. The estimated waste burned in Semarang City in 2020–2021 was 58.8 Gg/year, or approximately 9.70% of the total waste generated in Semarang City. This estimation exceeds local government estimates of 2020 by two-fold. Peri-urban areas (both inner and outer) were identified as the most significant contributors to waste burning. Further, garden waste was the most burned waste (73.61%), followed by plastic waste (17.45%). Other wastes, including paper, leather, textile, rubber, and food, were also burned. Overall, a decrease in the activity of waste burning is an important step for reducing the potential of air pollution and climate change.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10163-022-01371-3.

Bromination mechanisms of aromatic pollutants: formation of Br2 and bromine transfer from metallic oxybromides.

Bromination mechanisms of aromatic pollutants assume a chief contribution in the observed yields and pattern's distribution of a wide array of dioxin-like toxicants. However, salient features of the governing pathways remain largely speculative. This study presents detail mechanistic insights into two commonly discussed routes; namely: surface-assisted conversion of HBr into Br2 and direct bromine transfer from oxybromides into a benzene ring. Utilizing iron surfaces, as structural representative of the metallic content in electronic wastes, results from density functional theory calculations portray accessible reactions into the successive dissociative adsorption of HBr over the Fe(100) surface and the subsequent evolution of gas phase bromine molecules. Activation energies for HBr uptake by the plain iron surface reside in the range of 129-182kJ/mol. Over an oxygen pre-covered surface, dissociative adsorption of HBr leading to bromine molecules requires significantly lower activation energies (45-78kJ/mol). Likewise, bromination of a benzene ring into a monobromobenzene molecule over Fe(100)_O*Br* (i.e., an oxybromide) configuration ensues with an opening activation energy of ~ 165kJ/mol. Adsorption of a phenyl radical over an iron-oxybromide forms a phenolate moiety that subsequently desorbs from the surface into a phenoxy radical. Reaction pathways presented herein shall be useful in the ongoing efforts to comprehend the formation and bromination routes of the notorious bromine-bearing pollutants in real scenarios, such as, these encountered in the open burning and primitive thermal recycling of electronic wastes.

Polybrominated diphenyl ethers (PBDEs) concentrations in soil, sediment and water samples around electronic wastes dumpsites in Lagos, Nigeria

Polybrominated diphenyl ethers (PBDEs) were listed in the Stockholm Convention as POPs because of their bio-accumulative, long-range and toxicity characteristics. Therefore, these should be managed and assessed by Parties of the convention in an environmentally sound manner. This present study assessed the status of PBDEs contamination at e-waste dumpsites in Lagos, Nigeria. Soil and sediment samples were collected from 3 e-waste dumpsites and water samples were collected from rain water ponds located within the e-waste dumpsites vicinities and control sites over a period of two years. The concentrations of ∑7PBDEs in soils from the e-waste dumpsites at 0–15 cm depth for the first and second year ranged from 141 to 302 ngg−1 dry weight, respectively while that of the control soils was 13.2–27.2ngg−1 dry weight. These high concentrations may be attributed to the fact that open burning of electronic waste was the regular method of reducing the volume of e-waste at the sites. PBDE levels across the soil profile from 0 to 45 cm depth showed a gradual increase in PBDEs accumulation in the topsoil and migration into the sub-soil over the period of 2 years, but with no significant difference (p-value = 0.89). Sediments and water from the rain water ponds around the dumpsites were found to be contaminated by PBDEs with levels ranging from 51.4 to 85.8ngg−1 and 14.4 to 27.4ngg−1, respectively, while levels in control for sediment and water are 11.5ngg−1 and 2.43ngg−1respectively.These, however indicates that there was significance difference between the PBDEs levels in water and sediment from the study sites with those of their respective controls (p-value for water was 0.01, while that for sediment was 0.03).The levels of PBDEs in this study sites were higher than those of the respective control. The range of PBDEs in e-waste dumpsites was comparable to those reported in USA and Europe but lower than those from China. Environmental samples from the e-waste dumpsites in Lagos were contaminated with PBDEs, there is therefore the need for proper disposal methods for end-of-life products especially those containing PBDEs in Nigeria.

A Review on the Effects of Flame Retardant Additives Towards the Environment and Human Health

Flame retardant additives (FRAs) are normally the addition of chemicals that function to prevent or slow the spread of fires. These chemicals are used in consumer products and industries and could retain in the environment even after several decades. The toxicity mechanism and risk assessment methods of FRAs are also discussed in this paper. Papers from Scopus, Elsevier, Environmental health perspectives (EHP), Research gate, Semantic scholar, Hindawi, and Pubmed from 2003 to recent years were reviewed to provide some views on the possible risks of FRAs and their pathways into our environment as well as into human body. While FRAs could enter the environment during the manufacturing process and the usage period, consumer items are treated with FRAs, through waste streams, during illegal open burning of solid wastes, from incineration plants from landfill leachate and wastewater treatment plant (WWTP) sludge. FRAs are hazardous to humans and the environment; therefore, toxicology assessment should also be consistently conducted on the latest FRAs to ensure that they would not have adverse effects on humans and the environment.

Assessing the environmental risk and pollution status of soil and water resources in the vicinity of municipal solid waste dumpsites.

Municipal solid waste management remains a major challenge for many developing countries where unsanitary and environmentally damaging practices, such as open dumping and burning of wastes, are consistently utilized as means of waste disposal. This study aimed to assess the impact of local dumpsites in a region in Southern Lebanon and to assess/determine the level of pollution they cause on local ecosystems and the concomitant risks to public health. Accordingly, soil and water samples were collected from the seven dumpsites that were investigated over the course of two seasons. Several biological, chemical, and physical parameters were examined, with the results being utilized to calculate a number of environmental indices. Results indicated that several soil parameters including TN (700-2400mg/kg), pH (8.3-8.7), COD (39-1995mg/kg), and sulfate levels (17.8-301.6mg/kg) were altered by the dumpsites. Heavy metal concentrations varied between dumpsites; however, the most commonly prevalent metals across all dumps were Fe (992-41,500mg/kg), Cr (17.4-139.5mg/kg), Zn (24.1-177.4mg/kg), Cu (9.42-148.2mg/kg), and Mn (25.2-776.5mg/kg), though recorded concentrations exceeded permissible limits only in certain instances. Evidently, soil samples collected at dumpsites had higher concentrations compared to the samples collected away from dumpsites reaching 27 times more in certain locations. The altered parameters have a direct effect on soil fertility and, if biomagnified, could disrupt crop yields and impact human health. Physiochemical properties and heavy metal concentrations in water samples were not significantly altered and were found to be within permissible limits. However, it is crucial to develop a monitoring and remediation plan to decrease the percolation of leachate to water resources.

An experimental simulation study of conventional waste burning practices in India for the assessment and inventorisation of PCDD/F/dl-PCB emissions

The paper reports an update to the polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) annual emission inventory of India from open burning of municipal solid wastes (MSW) through the generation of nation-specific emission factors for air (EFair) and burned residue (EFland) vectors. The MSW characteristics and modes of disposal practiced in Indian cities exhibits subtle variations from that of developed nations due to differences in food habits, living standards and climatic conditions. The annual emission calculations based on EFs from hitherto studies simulating conditions prevailing in developed countries can lead to anomalous accounting of emission levels. It is the first experimental study reported from Indian subcontinent to determine EFs of dioxins and dl-PCBs from MSW open burning by simulated combustion experiments conducted in a custom fabricated Open Burning Test Facility (OBTF) - “Burn Hut”, using real dumpsite waste samples. Iso-kinetic sampling and coning and quartering methods were employed for the sampling of air and land emissions from combustion experiments. The PCDD/F's EFair ranged from 3 to 675 μg toxicity equivalence (TEQ)/ton of waste with a geometric mean (GMair) of 67.0 μgTEQ/ton and EFland ranged from 10 to 2531 μgTEQ/ton waste (GMland – 100.0 μgTEQ/ton). The EFair and EFland of dl-PCBs ranged from 0.5 to 46 μgTEQ/ton (GMair 7.0 μgTEQ/ton) and 0.5 to 96 μgTEQ/ton of waste (GMland 6.0 μgTEQ/ton) respectively. A detailed assessment of correlations between emission and MSW composition/combustion practices were conducted along with a comparative evaluation of EFpresent vis-à-vis EFs reported elsewhere.

Open waste burning contrary to other air pollution-related perceptions and practices in Pokhara, Nepal

A cross-sectional survey was conducted in Pokhara, Nepal between February 3 and 12, 2018 to determine whether air pollution-related perceptions led to a reduction in open burning of waste. Of the 394 people interviewed, 58.3% expressed their concerns about health risks due to air quality. Multiple logistic regression identified that perceived health risk (AOR, 5.70; 95% CI, 3.44–9.45) was a significant predictor of refraining from actions that increase air pollution. While 90.6% of people used trash lorry to dispose domestic waste, 40.6% treated domestic waste by open burning. Unexpectedly, a high level of perceived health risks (AOR 1.72; 95% CI, 1.02–2.91), a high rated contribution of open waste burning to air pollution (AOR, 1.71; 95% CI, 1.06–2.78), and frequent refraining from actions that increase air pollution (AOR, 1.78; 95% CI, 1.08–2.94) were significant predictors of frequent open waste burning. The results implied urgent need for improvement in waste collection efficiency and raising awareness of health risks of open waste burning.

Estimating backyard waste burning emission: A case study of Tembalang Campus, Diponegoro University

This study analyzes the distribution and amount of CO, CO2, HC, and NOx gas emissions resulting from the open burning of backyard waste in Diponegoro University. The burned waste sample is taken from surrounding environment of Diponegoro University (Tembalang Campus) by taking 4 random samples (3 kg each). Emissions from CO, CO2, HC, and NOx gases were obtained from the 24 minutes combustion test. Furthermore, the gaseous pollutant emitted is measured using a gas analyzer. The burned waste comprised 73.77% of organic waste, 17.45% of plastic; 4.33% of paper; and 4.45% of other waste. The emission test results show that the highest CO, CO2, HC, and NOx emissions have occurred at 14, 20, 18, and 18 minutes, respectively. The combustion test reveals that an enormous amount of CO, CO2, HC, and NOx gas is emitted during uncontrolled waste burning. Because backyard wastes burning produce significant gaseous pollutants, several efforts are needed to reduce this practice.

Gridded distribution of total suspended particulate matter (TSP) and their chemical characterization over Delhi during winter.

In the present study, total suspended particulate matter (TSP) samples were collected at 47 different sites (47 grids of 5 × 5 km2 area) of Delhi during winter (January-February 2019) in campaign mode. To understand the spatial variation of sources, TSP samples were analyzed for chemical compositions including carbonaceous species [organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC)], water-soluble total nitrogen (WSTN), water-soluble inorganic nitrogen (WSIN), polycyclic aromatic hydrocarbons (16 PAHs), water-soluble inorganic species (WSIS) (F-, Cl-, SO42-, NO2-, NO3-, PO43-, NH4+, Ca2+, Mg2+, Na+, and K+), and major and minor trace elements (B, Na, Mg, Al, P, S, Cl, K, Ca, Ti, Fe, Zn, Cr, Mn, Cu, As, Pd, F, and Ag). During the campaign, the maximum concentration of several components of TSP (996 μg/m3) was recorded at the Rana Pratap Bagh area, representing a pollution hotspot of Delhi. The maximum concentrations of PAHs were recorded at Udhyog Nagar, a region close to heavily loaded diesel vehicles, small rubber factories, and waste burning areas. Higher content of Cl- and Cl-/Na+ ratio (>1.7) suggests the presence of nonmarine anthropogenic sources of Cl- over Delhi. Minimum concentrations of OC, EC, WSOC, PAHs, and WSIS in TSP were observed at Kalkaji, representing the least polluted area in Delhi. Enrichment factor <5.0 at several locations and a significant correlation of Al with Mg, Fe, Ti, and Ca and C/N ratio indicated the abundance of mineral/crustal dust in TSP over Delhi. Principal component analysis (PCA) was also performed for the source apportionment of TSP, and extracted soil dust was found to be the major contributor to TSP, followed by biomass burning, open waste burning, secondary aerosol, and vehicular emissions.