Total Suspended Particulate Matter Research Articles

Systematic underestimation of polycyclic aromatic hydrocarbon aqueous concentrations in rivers.

Polycyclic aromatic hydrocarbons (PAHs) are a widespread group of organic contaminants whose presence in water bodies is cause of severe concern. With few exceptions, the majority of PAHs is hydrophobic, presents a high adsorption affinity, and is thus primarily transported within river systems during high-flow events together with suspended particulate matter (SPM). Evidence exists of analytical challenges related to the incomplete extraction of PAHs adsorbed to solids and thus to a potential negative bias in the chemical analysis of PAHs in bulk water samples with high SPM content. Despite this, partly due to the elevated efforts required to collect representative samples containing sufficient SPM for the separate PAH analysis in this matrix, several investigations rely on the analysis of aqueous samples. This study tests the hypothesis that surveys based exclusively on bulk water may lead to a systematic underestimation of the real contamination level and transport of PAHs in rivers. Six high-turbidity events were examined in three Austrian rivers applying time-integrated sampling and simultaneously analyzing PAHs in total bulk water, filtered water, SPM, and supernatant. Despite an unavoidable degree of uncertainty in such challenging sampling scheme, the results indicate that measurements performed with best available standard methods in bulk water samples determined in average only about 40% of the theoretically expected total PAHs concentrations derived from the analyses in SPM. Such deviation has important implications for the reliable assessment of the compliance with environmental quality standards as well as for surveys aimed to estimate riverine loads, validate emission models, and understand the transport dynamics of PAHs in rivers. Whereas the first objective, e.g., in European countries, is alternatively achieved via monitoring in biota, the latter ones require efforts directed to complement monitoring campaigns with separate sampling of SPM, with monitoring of suspended solids transport to appropriately select and interpret the results of water samples and to improve the chemical analysis of PAHs in bulk water samples with high solids content.

Analysis of Suspended Particulate Matter in a Conventional Seed Spices Cleaning and Grading Industry: A Case Study of Unjha Vicinity in Gujarat, India

A large number of seed spices (Cumin, Fennel, Coriander, Fenugreek etc.) cleaning-grading units are situated in Gujarat and Rajasthan. In-plant study was performed in such a cleaning-grading industry located at Unjha (Gujarat) in collaboration with Centre for Research on Seed Spice (SDAU), Jagudan, Mehsana. Apprehension for wellbeing of workers of such dust/ suspended particulate matter (SPM) generating industries are growing with time. SPM samples were collected using standard High Volume Sampler and these samples were analyzed for their respirable suspended particulate matter (RSPM) and total SPM concentration (µg/m3). The highest concentration of RSPM (< 10 micron) inside the plant was found to be 20 x103 µg/m3, while the highest SPM concentration level was 168x103 µg/m3. The average particle size of SPM was 1.96 µ to 9.43 µ while that of RSPM was 1.7 µ. The Ambient air quality norms prescribed by Central Pollution Control Board (CPCB) for industrial areas limit these values to 100 µg/m3 (SPM) and 60 µg/m3 (RSPM). Such highly polluted in-plant atmosphere of seed spices cleaning-grading industry may cause severe health problems, leading to respiratory diseases among the workers. In order to protect the health of workers engaged in these industries, it is suggested to install the electrostatic precipitator (ESP) device and retrofitting of existing equipment (such that dust levels are within permissible limits) may be considered.

Assessment major NOx sources to nitrate of TSP around the Danjiangkou reservoir using isotopes and a Bayesian isotope mixing model

Nitrate (NO3−) is a key component of atmospheric particulate matter. However, studies quantifying NO3− formation and sources in water source areas remain scarce. This study employs NO3− concentration, dual isotopic analyses (δ15N, δ18O), and SIAR and PSCF models to elucidate NO3− formation mechanisms and apportion sources in the Danjiangkou Reservoir area. The result showed that the concentration of NO3− (0.52 μg m−3-2.39 μg m−3), δ15N–NO3- (−2.3‰-4.2‰) and δ18O–NO3- (64.2‰–96.6‰) values varied seasonally in total suspended particulate matter (TSP). The contribution of the NO2 + ·OH pathway was the highest in summer (84%), while the main contributions came from the N2O5 + H2O and NO3 + VOCs pathways in winter (75%). The SIAR model revealed that the contributions of coal combustion and traffic emissions were 34% and 23%, respectively, indicating that fossil fuel release contributed most. Moreover, the contribution of biomass combustion sources was 31%, and soil emission sources had the least (12%). Considering liquefied petroleum gas, gasoline, and diesel vehicles as traffic emission sources, their contribution to NO3− in TSP increased to 50%. The PSCF analysis indicated that external input areas were predominantly from central Henan Province, northern Hubei Province, and central Shaanxi Province. This study quantitatively analyzed the sources of NO3− in atmospheric particulate matter in water sources for the first time, indicating that controlling the emissions of nitrogen oxides from gasoline cars, heavy-duty diesel trucks, and ships could help alleviate haze pollution and enhance air quality in the Danjiangkou reservoir area.

Detection of Autumnal Concentration of Coscinodiscus granii in the Southern Baltic—A Method for In Situ Measurement of Marine Particles

Efficient means for measuring the abundance and species composition of phytoplankton in situ continue to pose a big challenge to scientists. Hitherto, analyses and interpretations have been based mainly on small numbers of data acquired from microscopic examinations of water samples. Hence, information on devices facilitating such measurements is highly desirable. This paper examines the opportunities offered by the LISST-100X instrument for measuring in situ the concentrations and spatially variable biovolumes of a species dominant in the southern Baltic during the autumnal bloom. Microscopic analysis of phytoplankton in water sampled from different locations in the southern Baltic confirmed earlier results, indicating that this bloom was due to the overriding prevalence of one microplankton diatom species—Coscinodiscus granii. Combining the microscopic measurements of C. granii cell sizes with the size distribution ranges employed by the LISST-100X yielded equivalent spherical diameters (EDSs) ranging from 47.4 to 188.0 µm, with maxima in the 78.4–92.6 and 92.6–109 ranges. Comparative analysis of the particle size distribution (PSD) spectra was used to separate the abundance of C. granii from the total suspended particulate matter (SPM). Spatial in situ measurements in 2012 and 2014 of C. granii concentrations in surface waters showed that both its abundance and its percentage contribution to the total SPM were highly variable. Over a distance of several km, these concentrations varied from values close to zero to 0.2 µL L−1 in 2012 and from 0.3 to 0.9 µL L−1 in 2014, whereas the percentage in the total SPM was found to vary locally from a few to c. 50%. The proposed method and results demonstrate the success of the LISST-100X instrument in detecting size and volume concentrations of phytoplankton in size classes ranging from 1.25 to 250 μm. However, the correct interpretation of LISST data requires that the dominant phytoplankton species concentration in the suspensions be large enough for the signal (peak) to be readily visible against the background PSD of other SPM.

Source analysis and health risk assessment of polycyclic aromatic hydrocarbon (PAHs) in total suspended particulate matter (TSP) from Bengbu, China

The polycyclic aromatic hydrocarbon (PAH) concentrations in total suspended particulate matter (TSP) samples collected from October, 2021 to September, 2022 were analyzed to clarify the pollution characteristics and sources of 16 PAHs in the atmospheric TSP in Bengbu City. The ρ(PAHs) concentrations ranged from 1.71 to 43.85 ng/m3 and higher concentrations were detected in winter, followed by spring, autumn, and summer. The positive matrix factorization analysis revealed that, in spring and summer, PAH pollution was caused mainly by industrial emissions, gasoline and diesel fuel combustion, whereas in autumn and winter, it was coal, biomass and natural gas combustion. The cluster and potential source factor analyses showed that long-range transport was a significant factor. During spring, autumn, and winter, the northern and northwestern regions had a significant impact, whereas the coastal area south of Bengbu had the greatest influence in summer. The health risk assessment revealed that the annual total carcinogenic equivalent concentration values for PAHs varied from 0.0159 to 7.437 ng/m3, which was classified as moderate. Furthermore, the annual incremental lifetime cancer risk values ranged from 1.431 × 10−4 to 3.671 × 10−3 for adults and from 6.823 × 10−5 to 1.749 × 10−3 for children, which were higher than the standard.

Airborne Suspended Particulate Matter and the Prevalence of Allergic Conjunctivitis in Japan.

Background This study aimed to examine the association of suspended particulate matter (SPM) with outpatient attendance for allergic conjunctivitis. Methodology The information on air pollution, encompassing total hydrocarbons, non-methane hydrocarbons, methane, carbon monoxide, nitrogen oxide, nitric oxide, oxidants, and SPM alongside data concerning daily weather conditions such as temperature, wind speed, and humidity, was gathered. Subsequently, the weekly mean values for outpatient visits, air pollution, and weather parameters were computed. Results The number of outpatient visits for allergic conjunctivitis was significantly associated with SPM levels (r = 0.70, p = 0.0037), oxidant levels (r = 0.70, p = 0.0038), wind speed (r = 0.48, p = 0.0472), and humidity (r = 0.77, p = 0.0009) from January to March, as well as SPM levels (r = 0.53, p = 0.0309) and carbon monoxide (r = 0.56, p = 0.0230) from April to June. Multivariate analysis showed that SPM (odds ratio = 1.37, p = 0.0161) and wind velocity (odds ratio = 1.52, p = 0.0038) were significant predictors of the number of outpatient visits from January to December. Conclusions SPM levels were the only independent predictor of outpatient visits for allergic conjunctivitis, suggesting that SPM contributes to the pathophysiology of this condition.

An Investigation into A Socio-Economic Fit Between Vehicular Emissions and Economic Activities: A Case Study of Commercial Vehicles

Vehicular emission is one of the challenges in managing environmental pollution. The present study is designed to find a socio-economic fit between economic activities and the resultant emissions associated with automobiles. To proceed, it focuses on estimating seven different types of vehicular emissions; carbon monoxide, carbon dioxide, nitrogen oxide, particulate matter 2.5 and 10, volatile organic compounds, and the total suspended particulate matter. This exercise is based on data from a sample of 1200 respondents from the district of Peshawar. Results demonstrate that socio-economic factors and vehicle-specific characteristics significantly affect the excessive vehicular emission in the study area. It has been found that the socio-economic variables like age of respondent, education of respondents, and family size of the respondent, earning members in respondent’s family, monthly income of the respondents, total household expenditures, and wealth are factors significantly affecting commercial automobiles' emissions. Moreover, it was found that the cost incurred on the maintenance of the vehicle by the owner/driver is within the income range of the respondent. Based on the results, it is recommended that the identification and countering of challenges being raised by the emissions from commercial automobiles is very important for both the environment and the economy. This can only be done by a comprehensive cost-benefit analysis among different but conflicting priorities. As a top priority, the Khyber Pakhtunkhwa Government Driving School may be revamped to impart more efficient and effective training on road awareness and the resultant emissions from automobiles. Similarly, the Khyber Pakhtunkhwa Vehicle Emissions Testing Station (VETS) should be upgraded with the latest as well as smart machinery and equipment, especially the mobile testing stations that operate in shifts to cover the round-the-clock monitoring. Also, the emission fitness certificate shall be made conditional for the annual tax token renewals. The replacement of old and outdated engines with modern Euro–VI engines shall be incentivized so that the drivers are encouraged for the shift, ultimately benefiting both the environment and the drivers economically.

Attributing Atmospheric Phosphorus in the Himalayas: Biomass Burning vs Mineral Dust.

Atmospheric phosphorus is a vital nutrient for ecosystems whose sources and fate are still debated in the fragile Himalayan region, hindering our comprehension of its local ecological impact. This study provides novel insights into atmospheric phosphorus based on the study of total suspended particulate matter at the Qomolangma station. Contrary to the prevailing assumptions, we show that biomass burning (BB), not mineral dust, dominates total dissolved phosphorus (TDP, bioavailable) deposition in this arid region, especially during spring. While total phosphorus is mainly derived from dust (77% annually), TDP is largely affected by the transport of regional biomass-burning plumes from South Asia. During BB pollution episodes, TDP causing springtime TDP fluxes alone accounts for 43% of the annual budget. This suggests that BB outweighs dust in supplying bioavailable phosphorus, a critical nutrient, required to sustain Himalayas' ecological functions. Overall, this first-hand field evidence refines the regional and global phosphorus budget by demonstrating that BB emission, while still unrecognized, is a significant source of P, even in the remote mountains of the Himalayas. It also reveals the heterogeneity of atmospheric phosphorus deposition in that region, which will help predict changes in the impacted ecosystems as the deposition patterns vary.

Studies on the airborne bacterial communities and antimicrobial resistance genes in duck houses based on metagenome and PCR analysis

The threat of antimicrobial resistance (AMR) is on the rise globally, especially with the development of animal husbandry and the increased demand for antibiotics. Livestock and poultry farms, as key sites for prevalence of antibiotic-resistant bacteria (ARB), can spread antimicrobial resistance genes (ARGs) through microbial aerosols and affect public health. In this study, total suspended particulate matter (TSP) and airborne culturable microorganisms were collected from duck houses in Tai'an, Shandong Province, and the bacterial communities and airborne ARGs were analyzed using metagenomics and PCR methods. The results showed that the bacterial communities in the air of duck houses were mainly Actinobacteria, Firmicutes, Proteobactria, Chlamydia, and Bcateroidetes at the phylum level. At the genus level, the air was dominated by Corynebacterium, Jeotgalicoccus, Staphylococcus, Brevibacterium, and Megacoccus, and contained some pathogenic bacteria such as Staphylococcus aureus, Corynebacterium diphtheriae, Klebsiella oxytoca, Acinetobacter baumannii, and Pseudomonas aeruginosa, which were also potential hosts for ARGs. The airborne ARGs were mainly macrolides (10.97%), penicillins (10.73%), cephalosporins (8.91%), streptozotocin (8.91%), and aminoglycosides (8.02%). PCR detected 27 ARGs in airborne culturable microorganisms, and comparative analysis between PCR and the metagenomic data revealed that a total of 9 ARGs were found to the same, including macrolides ErmA, ErmF, tetracyclines tetG, tetX, methicarbamazepines dfrA12, dfrA15, aminoglycosides APH3-VI, ANT2-Ⅰ, and sulfonamides sul2. Moreover, inhalation exposure modeling showed that the workers in duck houses inhaled higher concentrations of ARB, human pathogenic bacteria (HPB) and human pathogenic antibiotic-resistant bacteria (HPARB) than hospital workers. These results provide new insights into airborne microorganisms and ARGs in animal farms and lay the foundation for further study.

Spatiotemporal Evolutions of the Suspended Particulate Matter in the Yellow River Estuary, Bohai Sea and Characterized by Gaofen Imagery

Suspended particulate matter is a crucial component in estuaries and coastal oceans, and a key parameter for evaluating their water quality. The Bohai Sea, a huge marginal sea covering an expanse of 77,000 km² and constantly fed by numerous sediment-laden rivers, has maintained a high level of total suspended particulate matter (TSM). Despite the widespread development and application of TSM retrieval algorithms using commonly available satellite data like Landsat, Sentinel, and MODIS, developing TSM retrieval algorithms for China’s Gaofen (GF) series (GF-6 and GF-1) in the Bohai Sea is still a great challenge, mainly due to the limited applicability of empirical algorithms. In this study, 259 in situ measured-TSM samples were collected for algorithm development. The remote sensing reflectance (Rrs) curve demonstrates prominent peaks between 550 and 580 nm. Through conversion to remote sensing reflectance, it was found that single-band data had a weak correlation with TSM, reaching a maximum correlation of 0.44. However, by combining bands of band ratio calculations, the correlation was enhanced. Particularly, the blue and green band equivalent Rrs ratio had a correlation coefficient of 0.81 with TSM, and the proposed TSM inversion exponential algorithm developed based on this factor obtained an R-squared (R²) value of 0.76 and a mean relative error (MRE) of 32.24%. Analysis results indicated that: (1) there are spatial variations in the TSM within the Bohai Sea, Laizhou Bay, and the Yellow River estuary, with higher levels near the coast and lower levels in open waters. The Yellow River estuary experiences seasonal fluctuations higher TSM during spring and winter, and lower variations during summer and autumn, and (2) the dynamics of TSM are affected by Yellow River runoff, with increased runoff leads to higher TSM levels and expanded turbid zones. This study proposes a new algorithm to quantify TSM evolutions and distributions in the Bohai Sea and adjacent regions using China’s Gaofen imageries.

Atmospheric Transport of Adulticides Used to Control Mosquito Populations across an Urban Metropolitan Area

Pesticides registered with the U.S. EPA for mosquito control are called adulticides and are released directly into the atmosphere as aerosols to target flying mosquitos. This adulticide application approach is different from traditional (agricultural) pesticide applications, yet the fate and transport of adulticides in large metropolitan areas is largely unknown. The Houston Metropolitan Area encompasses eight counties, many of which require county-level mosquito control programs that utilize adulticides. Malathion and permethrin are the primary adulticides used by Harris County (HC) in Houston, TX, USA. Houston, like many other metropolitan areas, has an urban atmosphere supporting the oxidation of both gas and particle phase pollutants. During the summer mosquito season of 2016, we collected atmospheric total suspended particulate matter (PM) samples at Jones Forest (JF), located in Montgomery County (directly north of HC) to investigate the atmospheric transport and oxidation of adulticides in an urban atmosphere. Despite HC alternating the adulticide treatment schedule, we measured permethrin, malathion, and malaoxon (oxidation product of malathion), throughout the sampling campaign. These consistent measurements, in conjunction with 12 h backward trajectories, support the conclusion that JF is influenced by other county-level mosquito-control programs and agricultural pesticide use. This cross-county transport may impact adulticide effectiveness by supporting pesticide resistance in mosquito populations due to repeated exposures to pesticides. This study highlights the need for mosquito control collaborations between counties, especially in areas of urban expansion overlapping with agricultural activities.

Bee Pollinator Mortality Due to Pesticide-Laden Particulate Matter from Beef Cattle Feedyards.

Wild and managed bees are critical for the stability of trophic webs, angiosperm reproduction, and agricultural productivity. Unfortunately, as many as 40% of crop pollinators are in a steep decline due to habitat loss and exposure to agrochemicals. Pyrethroids, neonicotinoids, and macrocyclic lactones are among the many agrochemicals toxic to pollinating insects that are used extensively in industrial beef cattle feeding operations throughout the world. Fugitive feedyard particulate matter (PM) transports agrochemicals into the surrounding environs. To determine the impact of agrochemical-laden feedyard particulate matter on bee pollinators, we conducted in situ experiments wherein honeybees and mason bees were placed downwind and upwind of feedyards (N = 40). Concurrent, colocated total suspended particulate matter samples contained multiple insecticides and parasiticides including pyrethroids, neonicotinoids, and macrocyclic lactones, in significantly higher concentrations downwind of feedyards (bifenthrin, 8.45 ± 4.92; permethrin, 1032.34 ± 740.76; clothianidin, 3.61 ± 1.48; imidacloprid, 73.32 ± 47.52; thiamethoxam, 5.81 ± 3.16; abamectin, 0.45 ± 0.29; ivermectin, 8.88 ± 5.06 ng/g). Honeybees and mason bees sited downwind of feedyards always experienced higher mortality than those correspondingly sited upwind, and male mason bees experienced significantly higher mortality compared to females when both were sited downwind. Bees occurring downwind of beef cattle feedyards for 1 h are 232-260% more likely to die than those occurring upwind. Thus, agrochemicals used on and emitted from beef cattle feedyards are significant threats to bee pollinators.

How has COVID-19 medical face mask altered the dynamics of pollutants from incinerated wastes?

The COVID-19 pandemic caused the disposal of an unprecedentedly huge amount of medical face masks, part of which were burnt or incinerated alongside other solid wastes. In this study, we investigated how the presence of the common medical masks may have altered the nature and quantities of pollutants normally associated with the burning of solid wastes. It was found that the addition of increasing amount of face masks (at 1.82%, 3.71% and 5.67% by mass) to solid wastes had no influence on the types of pyrogenic PAHs (polycylic aromatic hydrocarbons) present in the combustion residues. However, presence of the masks at 5.67% led to a drastic reduction in PAHs concentration (∑16PAHs = 0.83 ± 0.047 mg/kg, compared to the concentration measured when the face masks were not incorporated, ∑16PAHs = 4.65 ± 0.23 mg/kg). Mixtures containing 3.71% and 5.67% of masks caused increases in total suspended particulate matter (TPM) by 475.6% and 796.4%, respectively. Presence of the masks at 3.71% and 5.67% also led to emission of poisonous carbon (II) oxide gas above the environmental safe limit of 29 mg/m3. Furthermore, addition of face masks led to higher concentrations of highly toxic metals (As, Cd, Pb and Cu) in the combustion residues of the solid wastes. Overall, this study demonstrates that medical face masks are better incinerated separately, rather than combining them with regular solid wastes. The findings are invaluable for ongoing management of used face masks in health facilities around the world, and in event of any future global or regional pandemic.

Analysis of metals in particulate matter suspended in air by total reflection x‐ray fluorescence

AbstractAtmospheric particulate matter (PM) is considered to be a set of pollutants suspended in the air, from industrial processes, motor vehicle exhaust, resuspended street dust, biomass burning, and others. Among the toxic chemical compounds, PM is considered contaminants of great importance for researchers, as they offer harmful effects to humans, fauna and flora. Moreover, exposure to PM can cause the development and/or worsening of diseases, mainly respiratory and cardiovascular. The aim of the present study was to evaluate the metals concentration in total suspended particulate matter in the air through total reflection x‐ray fluorescence technique (TXRF). The samples were collected from random points in five neighborhoods in the Metropolitan Region of the state of Rio de Janeiro/Brazil. TXRF measurements were performed using the benchtop TXRF spectrometer S2 PICOFOX. The results showed that the proposed methodology was able to detect the elements Cr, Fe, Ni, Cu, and Zn, in concentrations ranging from 2.0 to 200 ng.m−3. It can be concluded that the study methodology for determining the metal concentrations in air samples is an efficient and low‐cost solution for studying environmental pollution.

Carbonaceous component of Total Suspended Particulate (TSP) in Makassar City, Sulawesi Island, Indonesia

As the initial study related to carbonaceous components in Sulawesi Island, Indonesia, total suspended particulate matter (TSP) was collected in the roadside environments in Makassar city, Indonesia. The mean TSP level in this study was higher than the National Ambient Air Quality Standard (NAAQS) of Indonesia and much higher than World Health Organization (WHO) standards. It ranged from 21.6 to 838.6 μg/m3. The lowest concentration was found during the rainy days in paved site. The highest TSP level in all sites was found in the rush morning and late noon hour. It is related to the movement of the citizens during those periods of time. Regardless of the sites and times of sampling, organic carbon (OC) is the main fraction of total carbon (TC) for around 62.2 – 84.0%. OC and EC had well correlation indicating both carbonaceous components were emitted from the common sources. It might be emitted from the traffic emission as seen from the greater correlation between TSP and soot-EC than between TSP vs. char-EC. Hence, exhaust emissions from traffic and non-exhaust emission during the movement of vehicles should be the two main sources of TSP and its carbon components in the roadside environment of Makassar city, Sulawesi Island, Indonesia.

Variability of light absorption coefficients by different size fractions of suspensions in the southern Baltic Sea

Abstract. Measurements of light absorption coefficients by particles suspended in seawater (ap(λ)), by phytoplankton (aph(λ)) and detritus (ad(λ)) were carried out in the southern Baltic Sea for the original seawater samples and four size fractions: pico-particles (0.2–2 µm), ultra-particles (2–5 µm), nano-particles (5–20 µm) and micro-particles (20–200 µm). Chlorophyll a (Chl a) and suspended particulate matter (SPM) concentrations were determined. The proportions of particles from the size classes in the ap(443), aph(443) and ad(443) were determined. Pico- and ultra-particles had the largest contribution to the total particle absorption – an average of 38 % and 31 %. Particles of 5–20 µm accounted for approximately 20 % of ap(443) and aph(443) and 29 % of ad(443). The contribution of particles > 20 µm averaged 5 %–10 %. In total SPM contribution of micro-particles averaged 17 %; nano-, ultra- and pico-particles averaged 29 %, 26 % and 27 %, respectively. In total Chl a, the proportions of pico- and ultra-particles averaged 35 % each, nano-particles 16 % and micro-particles 15 %. Temporal and spatial variability of particles contributions in size classes were observed. The average chlorophyll-specific and mass-specific light absorption coefficients, i.e., light absorption coefficients normalized to Chl a or SPM, were determined for all size fractions. The chlorophyll-specific coefficients ap(Chla)(λ), ad(Chla)(λ) and aph(Chla)(λ), ± standard deviations, do not allow clear separation of the individual fractions. For mass-specific coefficients, ap(SPM)(λ), ad(SPM)(λ) and aph(SPM)(λ), it is possible to distinguish between large particles (20–200 µm) and small and medium particles (0.2–20 µm). These results will allow monitoring of suspended matter in size classes in optically complex waters of southern Baltic Sea.

Development of an emission estimation method with satellite observations for significant forest fires and comparison with global fire emission inventories: Application to catastrophic fires of summer 2021 over the Eastern Mediterranean

In the past few decades, forest fires have increased in number and severity, especially in the Mediterranean regions of Türkiye and Greece, where significant fires caused damage to thousands of hectares of land as well as wildlife. The main objective of the present study is to develop an emission estimation method with satellite-based burned area data from significant forest fire events in the Eastern Mediterranean in July–August 2021. In the first stage of this study, pre-fire and post-fire images of the study area acquired by the Sentinel-2 satellite were processed to calculate the normalized burn rate difference index (dNBR). Then, CORINE Land Cover (CLC) data were used for detecting land cover classes in the burned areas. Atmospheric emissions of NOx, CO, SO2, total suspended particulate matter (TSP), particulate matter with diameters that are equal to or smaller than 2.5 μm (PM2.5), and black carbon (BC) were estimated using the EMEP/EEA Tier 2 - technology-specific approach method, in which burned area maps were retrieved using Sentinel-2 imageries and later combined with land cover type and burning efficiency to estimate the quantity of burning biomass emissions. Emission factors were then used to estimate the fires' trace gas and aerosol emissions. The results showed that the highest burned areas were found in the western Mediterranean region in Türkiye and Central Greece (⁓50,000 ha). The atmospheric emissions from these fires were calculated to be similar in both countries. Furthermore, emission amounts were compared with three different global fire emission inventories including GFAS, GFED, and FINN. The emissions obtained from the GFAS database were the highest emissions of the four emission estimation approaches and our estimated emissions were close to the GFAS. Emissions calculated from the other two databases (FINN and GFED) mostly provided underestimated emissions. The emission uncertainties in this study mainly originated from assumptions regarding the inclusion of burned area efficiency in emission calculations, the landcover dataset, and the emission factors used. Overall, this study is considered a new approach to emission calculations using Sentinel-2 data. This research provides further insight into the use of Sentinel-2 data in emission calculation applications at the local to regional scales.

SARS-CoV2 in public spaces in West London, UK during COVID-19 pandemic

BackgroundSpread of SARS-CoV2 by aerosol is considered an important mode of transmission over distances >2 m, particularly indoors.ObjectivesWe determined whether SARS-CoV2 could be detected in the air of enclosed/semi-enclosed public...

Drug substances in the air of a New Zealand city

Nicotine, caffeine, methamphetamine, and Δ9-tetrahydrocannabinol (THC) were quantified in the total suspended particulate matter of New Zealand's largest city (Auckland), representing the first study of airborne drug concentrations in Oceania. The average airborne concentrations for each drug over the 5-week study were as follows: nicotine (4.91 ± 1 ng m−3), caffeine (16.1 ± 2 pg m−3), methamphetamine (24.8 ± 3 pg m−3), and THC (1.87 ± 0.2 pg m−3). Nicotine and caffeine were higher during weekdays while illicit drugs methamphetamine and THC were higher on weekends, with the lone exception being the weekday sample that overlapped New Year's Eve. Airborne caffeine concentrations correlated with urban pedestrian counts (P = 0.009), demonstrating that atmospheric caffeine concentrations may be an indicator for urban activity. Laboratory contamination of caffeine occurred after the analyst had consumed coffee, highlighting the importance of using laboratory controls when doing trace level analysis. The airborne monitoring of drugs may serve as a complementary technique to wastewater analyses, potentially providing higher resolution spatial data related to locations of drug use, handling, and manufacture. Airborne drug monitoring may also be useful for jurisdictions planning to assess policy performance, such as restrictions on the use and sale of smoked tobacco products in New Zealand.

ESTIMATION OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH’s) PRESENT IN THE ATMOSPHERE OF URBANIZED REGION BADAMI BAGH IN LAHORE, PAKISTAN

The emerging mega city of Lahore has been progressing by leaps and bounds in lasttwo decades which is directly related to an immense increase of number of vehicles and powergeneration systems using fossil fuels. The present study entails the quantification and evaluation ofpotential risk due to Polycyclic Aromatic Hydrocarbons (PAHs) which is one of the known organicpollutants from vehicular, power generation system’s exhaust and other industrial activities. Thesamples of Total Suspended Particulate Matters (TSPM) were collected from various urbanized sitespresent at Badami Bagh, Lahore, Pakistan for the estimation of polycyclic aromatic hydrocarbons. Thetechnique used for quantification of PAH’s was Gas Chromatography. The concentration of mean totalof PAH was 746.60 ng/m3. Dibenzo(a,h) Anthracene was found to be in highest concentration of142.35 ng/m3 among all the polycyclic aromatic hydrocarbons under investigation.