Low-volume Sampler Research Articles

Optical characteristics of brown carbon in the atmospheric particulate matter of Dhaka, Bangladesh: Analysis of solvent effects and chromophore identification

The prevalence of brown carbon (BrC) in the atmosphere has experienced a notable upsurge owing to human activities of anthropogenic origin. This study aims to examine the optical characteristics of BrC in both deionized (DI) water and organic solvents (OS), alongside the identification of BrC chromophores within the ambient atmosphere of Dhaka, Bangladesh. Particulate matter (PM) samples were collected on quartz filters using a low-volume sampler from December 2021 to May 2022 at Mukarram Hussain Khundker Bhaban, University of Dhaka. The concentration of BrC was measured using soot analyzer, optical properties of BrC were determined using UV–Vis spectrometer, and BrC chromophores were identified with GC-MS. Average concentration of BrC was 19.13 ± 5.71 μgm−3. The average of absorption coefficient (babs_365), mass absorption efficiency (MAE), absorption angstrom exponent (AAE), and refractive index (kabs_365) of BrC_DI have been observed to be 38.75 ± 21.90 Mm−1, 2.16 ± 1.42 m2 g-1, 1.51 ± 0.08, 0.06 ± 0.04, respectively. The absorption coefficient and MAE of BrC_OS are 1.3 and 1.36 times, respectively higher than that of BrC_DI. Thirty chromophores of BrC have been identified, predominantly consisting of oxygenated compounds. Derivatives of Bisphenol A (C27H44O2Si2) were detected in all samples of oxygenated compounds, primarily originating from the combustion of plastic and the incineration of e-waste. Additionally, compounds containing nitrogen and sulfur, such as C14H26N2O, C31H55N, and C31H49NO3S, were identified, largely attributed to biomass combustion and traffic emissions. These chromophores play a significant role in the absorption of solar radiation, thus influencing atmospheric photochemistry.

Characterization of aerosol and its oxidative potential in a coastal semi-rural site of Southern Italy

Considering the scarce number of studies investigating the oxidative potential of PM2.5 in Italy, a measurement campaign was conducted from February 2020 to October 2020 in a coastal semi-rural site of Basilicata (Southern Italy) with the goal to characterize the fine fraction of ambient particulate matter (PM) and investigate its chemical and toxicological properties, by means of oxidative potential. Different instruments such as an automatic low-volume sampler, an aethalometer and an optical particle counter, were employed for the measurement of PM2.5 mass concentration, equivalent black carbon (eBC) concentration and absorption Ångström exponent (AAE), and particle number size distribution in 0.25–31 μm size range, respectively. 108 daily PM samples, collected on quartz fibre filters, were chemically analysed. Organic (OC) and elemental (EC) carbon content was estimated by thermo-optical transmittance technique (TOT), the concentrations of the main water-soluble ions and total elements were determined by ion chromatography and ED-XRF technique, while the oxidative potential of the water-soluble fraction was estimated through the dithiothreitol (DTT) assay. The mean value of PM2.5 mass concentration was 9.2 ± 2.5 μg/m3 and the average contribution of measured species on PM2.5 mass was 3.3% EC; 19.3% OC; 27.0% secondary inorganic aerosol (sum of SO42−, NH4+ and NO3−), and 10.2% of the other ions and elements. The OC and EC contributions to PM2.5 mass and their mean ratio (OC/EC = 6.6 ± 3.1) suggest that the site is affected by the combined contribution of traffic emissions and biomass combustion (domestic heating and agricultural activities), with the latter prevailing over the traffic, as supported by the mean AAE value of 1.3. The mean OP normalized by sampled volume, OPDTTV, was as high as 0.34 ± 0.22 nmol/min·m3, a value comparable to those recorded for PM2.5 in suburban areas of Italy. The correlation between OPDTTV and the chemical species observed in the PM2.5 samples showed a good agreement with the carbonaceous component OC (r = 0.62) and with some ions, K+ and SO42− (r = 0.60). These results identify combustion sources as the most responsible for the relatively high OPDTTV activity of PM2.5 recorded in this area.

Review on Sampling Methods and Health Impacts of Fine (PM2.5, ≤2.5 µm) and Ultrafine (UFP, PM0.1, ≤0.1 µm) Particles

Airborne particulate matter (PM) is of great concern in the modern-day atmosphere owing to its association with a variety of health impacts, such as respiratory and cardiovascular diseases. Of the various size fractions of PM, it is the finer fractions that are most harmful to health, in particular ultrafine particles (PM0.1; UFPs), with an aerodynamic diameter ≤ 100 nm. The smaller size fractions, of ≤2.5 µm (PM2.5; fine particles) and ≤0.1 µm (PM0.1; ultrafine particles), have been shown to have numerous linkages to negative health effects; however, their collection/sampling remains challenging. This review paper employed a comprehensive literature review methodology; 200 studies were evaluated based on the rigor of their methodologies, including the validity of experimental designs, data collection methods, and statistical analyses. Studies with robust methodologies were prioritised for inclusion. This review paper critically assesses the health risks associated with fine and ultrafine particles, highlighting vehicular emissions as the most significant source of particulate-related health effects. While coal combustion, diesel exhaust, household wood combustors’ emissions, and Earth’s crust dust also pose health risks, evidence suggests that exposure to particulates from vehicular emissions has the greatest impact on human health due to their widespread distribution and contribution to air pollution-related diseases. This article comprehensively examines current sampling technologies, specifically focusing on the collection and sampling of ultrafine particles (UFP) from ambient air to facilitate toxicological and physiochemical characterisation efforts. This article discusses diverse approaches to collect fine and ultrafine particulates, along with experimental endeavours to assess ultrafine particle concentrations across various microenvironments. Following meticulous evaluation of sampling techniques, high-volume air samplers such as the Chem Vol Model 2400 High Volume Cascade Impactor and low-volume samplers like the Personal Cascade Impactor Sampler (PCIS) emerge as effective methods. These techniques offer advantages in particle size fractionation, collection efficiency, and adaptability to different sampling environments, positioning them as valuable tools for precise characterisation of particulate matter in air quality research and environmental monitoring.

A direct method to quantify methanol-soluble organic carbon for brown carbon absorption studies

The current research provides a newly developed method to quantify methanol-soluble organic carbon (MeS_OC) in aerosol samples. This analytical procedure allows an accurate separation of MeS-OC component, which is critical for the calculation of mass absorption efficiency (MAE) of ambient Brown Carbon (BrC) and consequently its climate relevant potential. The method includes extraction, filtering and condensation stages, leading to the preparation of a highly concentrated product in which MeS-OC can be precisely quantified by a Sunset Carbon Analyzer in a single analysis step. This method can be applied on aerosol collected using either high or low volume samplers, since a relatively small filter area is required for the determination. Furthermore, it eliminates any misestimation of the MeS-OC mass that may appear in other reported techniques that don't seem to include the precise separation of methanol-soluble fraction in their quantification process.•The mass quantification of methanol-soluble organic carbon is essential, contributing up to 50% to the absorptivity of organic aerosol (BrC) at shorter wavelengths.•The method provides a direct measurement of methanol-soluble aerosol components, resolving any potential uncertainties of previously applied methods.•The adoption of this direct quantification approach leads to a rationalization of past MAE estimates for BrC with implications for radiative transfer models.

A Study of Elemental Composition and Risk Assessment Due to Exposure to Indoor PM10 in Two Residences in Mexico City

Samples of airborne particles with aerodynamic diameters smaller than 10 µm (PM10) were collected in 2021 at two households in the Metropolitan Area of Mexico City. Both sites are in areas with different characteristics (residential or industrial zones). Simultaneous sampling indoors and outdoors was carried out at the two locations, using low-volume samplers. The study aimed to determine the indoor and outdoor gravimetric mass and elemental concentrations, identify emitting sources and possible penetration towards the households enhanced by natural ventilation, and assess risks to human health due to inhalation, ingestion, and dermal absorption, through hazard quotients. Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Se, and Pb concentrations were measured with X-ray fluorescence. Mass concentrations were higher indoors than outdoors, and most elemental concentrations had similar values in both environments. Cluster analysis was applied to identify possible emitting sources. The results showed a strong penetration of geogenic and industrial emissions at the Iztapalapa site, while only particles of industrial origin entered the interior of the Tlalnepantla dwelling, in both cases caused by the natural ventilation of the households. Health risks due to exposure to particles containing Fe, Ni, Cu, Zn, and Mn are not significant, and Pb and Cr only pose a risk via ingestion for men and women, although for children, there is a risk due to ingestion of all these elements.

From multi to single-particle analysis: A seasonal spectroscopic study of airborne particulate matter in Zaragoza, Spain

It is distinguished that deficient outdoor air quality is responsible for substantial health and climate issues. The aim of our study was to investigate the air quality in the city of Zaragoza (Spain) by characterizing atmospheric particulate matter (PM10) during two seasons (winter and spring). PM10 samples were collected in 2022 in quartz filters through a low-volume sampler and chemically analysed by complementary analytical techniques: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), Laser Induced Breakdown Spectroscopy (LIBS), Raman Spectroscopy (RS) and Field Emission Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (FESEM-EDS). Results have revealed, together with a temperature inversion phenomenon in winter, the presence of both natural (Al, Ca, Mg, Ti, Sr, Fe, etc.) and anthropogenic particles. The latter mainly formed by black carbon with an origin on fossil fuel combustion emissions. Additionally, chemical analyses of PM10 filters showed the presence of three types of microplastics suspended in the air of the city: polyethylene terephthalate (PET), polyamides (PA) and polystyrene (PS). The results obtained from this research are of special interest to take into account for future air quality policies, particularly those with the aim of reducing air pollution in cities.

Chemical composition, levels, and I/O ratios of PM10 and PM2.5 in the laboratory near the copper smelter in Bor, Serbia

Numerous studies have reported that particulate matter and its specific chemical constituents were linked to the incidence of respiratory diseases and mortality and lung function. The main aim of this study is to determine metallic content in PM10 and PM2.5 samples taken simultaneously at several locations in the close vicinity of the copper smelter in Bor and the influence of outdoor PM pollution on indoor PM levels. The measurement campaign was conducted, during the non-heating season of 2020. PM samples were collected at all sampling sites with low-volume samplers (Sven/Leckel LVS3) on quartz fiber filters (Whatman QMA, 47mm). All samples were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP MS). In this way, the mass concentrations of 4 priority elements (As, Cd, Pb, and Ni) in PM samples were identified and quantified. It has been determined that average indoor PM levels in the laboratory were higher than outdoors. A strong correlation was found between PM10 and PM2.5 particle levels inside the laboratory and in the outdoor air. Also, a very strong correlation was found between the levels of Pb, Ni, As, and Cd determined in PM10 and PM2.5 samples inside the laboratory and in the outdoor air. This confirms that mentioned elements originate from the same sources located in the copper smelter complex.

Atmospheric Abundance of PM2.5 Carbonaceous Matter and Their Potential Sources at Three High-Altitude Glacier Sites over the Indian Himalayan Range

This study inspects the concentrations of fine particulate matter (PM2.5) mass and carbonaceous species, including organic carbon (OC) and elemental carbon (EC), as well as their thermal fractions in the Indian Himalayan glacier region at the western Himalayan region (WHR; Thajiwas glacier, 2799 m asl), central Himalayan region (CHR; Gomukh glacier, 3415 m asl), and eastern Himalayan region (EHR; Zemu glacier, 2700 m asl) sites, throughout the summer and winter periods of 2019–2020. Ambient PM2.5 samples were collected on quartz fiber filters using a low-volume sampler, followed by carbon (OC and EC) quantification using the IMPROVE_A thermal/optical reflectance methodology. Different seasonal variations in PM2.5 and carbonaceous species levels were found at all three sites investigated. Averaged PM2.5 mass ranged 55–87 μg m–3 with a mean of 55.45 ± 16.30 μg m–3 at WHR, 86.80 ± 35.73 μg m–3 at CHR, and 72.61 ± 24.45 μg m–3 at EHR. Among the eight carbon fractions, high-temperature OC4 (evolved at 580 °C in the helium atmosphere) was the most prevalent carbon fraction, followed by low-temperature OC2 (280 °C) and EC1 (580 °C at 2% oxygen and 98% helium). Char-EC representing incomplete combustion contributed to 56, 67, and 53% of total EC, whereas soot-EC contributed to 38, 26, and 43% of total EC in WHR, CHR, and EHR, respectively. The measured OC/EC ratios imply the presence of secondary organic carbon, whereas char-EC/soot-EC ratios suggested that biomass burning could be the predominant source of carbon at CHR, whereas coal combustion and vehicular emission might be dominant sources at WHR and EHR sites.

Assessment of Atmospheric Pollutants Concentrations by Using Multivariate Statistical Analysis: A Case Study of Commune 5 of Niamey City, Niger

The aim of this present study is to determine the physicochemical properties of atmospheric particles in commune 5 of the Niamey region. For this purpose, the determination of the atmospheric physical and chemical properties was carried out using a low-volume sampler, a Davis-type weather station, a balance high sensitivity, The Thermo XL2 and the black carbon reflectometer. The pollutants concerned by this study are mainly fine particulate matter (PM2.5), black carbon and heavy metals such as Cr, Cu, Hg, Mn, Ti, V, Zn, Ba, Fe and Sr. According to the result of this study which is carried out over 30 days, the PM2.5 concentrations of air measured were between 0 and 286.54 μg/L with a mean value of 11.65 μg/L. The temperature values were between 24 and 27 °C with an average value of 25.3°C. The humidity value of measured air varies between 8 and 17 % with a mean value of 13.3 %. The measured wind speed values are between 3.24 and 6.48 Km/h with an average value of 4.14 Km/h. According to World Health Organization guidelines the PM2.5, Mn, Hg, Ba, Cr and black carbon concentrations measured during this study exceeded the permissible limit values. Correlation analysis results highlighted a strong correlation between Mn-Fe, Mn-Zn, Mn-Ti, Mn-V, Mn-Cr, Zn-Ti, Zn-V, Zn-Cr, Ti-V, and Ti-Cr indicating that these ions come from a common source. According to principal component analysis for heavy metals, three principal factors that explain 87.34% of the total variance have been formed. Component 1 includes V, Zn, Ti and Cr with a variance value of 56.067 %; the second factor includes Ba and black carbon with a variance value of 19.665 % and the third factor is only represented by Sr with a variance value of 11.612 %. The high value of variance observed in the first group of components indicated that V, Zn, Ti and Cr are the main pollutants that control the air pollution in the study area.

Exploring the Mass Concentration of Particulate Matter and Its Relationship with Meteorological Parameters in the Hindu-Kush Range

Particulate matter (PM) is among the deadliest air pollutants due to its negative health impacts and environmental harm. This study reports on monthly and seasonal concentrations of PM10, PM2.5, and PM1, along with their ratios. Twelve-day samples were collected once a month in Mingora city (Swat, Pakistan) from January to December 2019 using a low volume sampler. Maximum average mass concentrations of PM10, PM2.5, and PM1 were recorded in December having values of 78, 56, and 32 μg m−3, respectively. Minimum average values for PM10 (44 μg m−3) and PM2.5 (25.1 μg m−3) were recorded in April, while the lowest PM1 (11 μg m−3) was recorded in August. In comparison to other months, the maximum average mass concentrations were 1.77 times (PM10), 2.23 times (PM2.5), and 2.9 times (PM1) higher in December. During the winter season, average mass concentrations remained high. Substantial correlation coefficients of 0.92, 0.79, and 0.75 were recorded between PM10 and PM2.5, PM2.5 and PM1, and PM2.5 and PM1, respectively. The overall average ratios PM2.5: PM10, PM1: PM2.5, and PM1: PM10 were 68.3, 52.6, and 35.4%, respectively. A moderate negative correlation of PM10, PM2.5, and PM1 with wind speed (−0.34, −0.39, and −0.41), a strong negative correlation with temperature (−0.69, −0.71, and −0.74) and rainfall (−0.63, −0.61, and −0.59), and a weak relationship with relative humidity (−0.32, −0.1, and −0.02) were recorded.

Indoor particulate matter (PM2.5) in Malaysian academic building: Elemental characterization and source apportionment

This study aims to determine the elemental compositions of indoor particulate matter (PM2.5) in two selected academic buildings, with emphasis on source apportionment using a multivariate receptor model. PM2.5 samples were collected from lecture halls, laboratories and lecturer offices at the Ministry of Health Training Institute of Sungai Buloh (S1) and the Ministry of Health Training Institute of Sultan Azlan Shah (S2). Sampling took place over 8 h using a low volume sampler (LVS). In this study, various scientific methods such as standard methods for air quality analysis as well as Principal Component Analysis (PCA) and Multiple Linear Regression (MLR) were applied in order to investigate the elemental characterizations and source apportionment of PM2.5, respectively. The PM2.5 compositions for water-soluble ionic species (WSIS) and trace metals were analysed using ion chromatography (IC) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. Results showed that the mean PM2.5 concentration at S1 (108 ± 39.5 µg m−3) was higher than S2 (91.1 ± 36.6 µg m−3). PCA-MLR analysis revealed that biomass burning (48%) and building material/crustal origin (81%) were the major sources of indoor PM2.5 for S1 and S2, respectively. Modifications and improvements to ventilation systems could be implemented in order to maintain a good health of the building occupants as outside sources may contribute to the presence of pollutants in these buildings.

The Determinant of Lung Function Disorders of The Textile Industry Spinning Section

Many factors affect lung function capacity in textile industry workers. This research aims to determine the factors that affect the vital role of pulmonary spinning workers in the textile industry. This research used an analytic observational research design with a cross-sectional approach. The sampling technique used total sampling and getting the sample was 96 people, and measurement of lung vital capacity used spirometry. The Low Volume Sampler was applied to measure dust concentration, and the questionnaire was used to assess the individual characteristics. Bivariate analysis of the variables is the working environment dust, exercise habits, smoking behavior, and gender are significant. The result of multivariate analysis of dust is the most affecting to the lung vital capacity. In conclusion, dust concentrations are classified above the Threshold Limit Value (TLV), so the company should control the source of dust exposure.

The Influence of Environmental Polycyclic Aromatic Hydrocarbons (PAHs) Exposure on DNA Damage among School Children in Urban Traffic Area, Malaysia.

This study aimed to investigate the association between particulate PAHs exposure and DNA damage in Malaysian schoolchildren in heavy traffic (HT) and low traffic (LT) areas. PAH samples at eight schools were collected using a low volume sampler for 24 h and quantified using Gas Chromatography-Mass Spectrometry. Two hundred and twenty-eight buccal cells of children were assessed for DNA damage using Comet Assay. Monte-Carlo simulation was performed to determine incremental lifetime cancer risk (ILCR) and to check the uncertainty and sensitivity of the estimated risk. Total PAH concentrations in the schools in HT area were higher than LT area ranging from 4.4 to 5.76 ng m−3 and 1.36 to 3.79 ng m−3, respectively. The source diagnostic ratio showed that PAHs in the HT area is pyrogenic, mainly from diesel emission. The 95th percentile of the ILCR for children in HT and LT area were 2.80 × 10−7 and 1.43 × 10−7, respectively. The degree of DNA damage was significantly more severe in children in the HT group compared to LT group. This study shows that total indoor PAH exposure was the most significant factor that influenced the DNA damage among children. Further investigation of the relationship between PAH exposure and genomic integrity in children is required to shed additional light on potential health risks.

Children's exposure to PM2.5 and its chemical constituents in indoor and outdoor schools urban environment

A school environment with good indoor air quality contributes to the children's performance and learning efficacy. This study aims to determine indoor and outdoor PM2.5 concentrations in school environments and its possible sources and exposure levels. Daily measurements of PM2.5 samples were collected for 24 h using low volume samplers from 19 primary schools in densely populated areas of Kuala Lumpur. Chemical species of the PM2.5 were determined for trace metals, water soluble inorganic ions (WSII) and polycyclic aromatic hydrocarbons (PAHs) for both indoor and outdoor. The results showed that classroom indoor PM2.5 levels had an average concentration of 42.0 ± 23.1 μg m−3, which was not much different from outdoor levels, which have an average concentration of 39.9 ± 21.9 μg m−3. However, there was a significant difference between indoor and outdoor chemical constituents for Fe, Zn, Cu, Mn, Na+, B[b]F and B[a]P (p < 0.05). The major components of PM2.5 mass indoors and outdoors were SO42− (3.9% and 3.6%) and NO3− (2.4% and 2.4%), respectively. The results from Positive Matrix Factorization (PMF) identified building materials (34%) as the major source for indoors, while secondary pollutants (38%) were identified as the major source for outdoors. Hazard quotient (HQ) values for all metals were <1 indicated low non-carcinogenic risk to school children, while the excess lifetime cancer risk (ELCR) values were in the sequence of Cr > Ni > Cd > Pb. Overall, PM2.5 concentrations impacted the air quality in schools and posed health risks to children, which means measures need to be taken to reduce PM2.5 pollution in school environments.

Light absorption properties of brown carbon from biomass burning emissions.

A laboratory-scale experiment was conducted to determine the light absorption properties of brown carbon (BrC) produced from theincomplete combustion of 14 different biomasses. Particulate matters (PM) emitted from biomass burning were collected on the quartz fiber filters with a low volume sampler. BrC from filter samples was extracted with two different solvents (methanol and water), and absorption characteristics of BrC were determined using a UV-Vis spectrophotometer. The absorption coefficient (babs-BrC), mass absorption efficiency (MAEBrC), absorption angstrom exponent (AAEBrC), and absorbing portion of refractive index (kabs-BrC) were calculated for each biomass from the absorbance of the extracted solution. Methanol-soluble BrC (MeS-BrC) showed higher absorbance than water-soluble BrC (WS-BrC) in all biomasses. MeS-BrC has higher babs-BrC than WS-BrC, suggesting that the rate of light absorption on BrC extracted in methanol was higher. The absorption coefficients (babs-BrC) were varied among biomasses-rain tree had the highest value of babs-BrC, whereas jute stick had the lowest. The mass absorption efficiency of BrC (MAEBrC) was evaluated in both water and methanol extracts, and it was found that the MAEBrC for MeS-BrC in the biomasses was greater than that of WS-BrC. The highest MAEBrC value (13.02 m2g-1) wasidentified in the jackfruit tree, whereas the lowest MAEBrC value (0.1 m2g-1) wasobserved in thejute stick. The absorption angstrom exponent (AAE) of both WS-BrC and MeS-BrC was determined which represents the light absorption capacity of the aerosol particles. The highest AAE value was found in cow dung, and the lowest was found in rain tree. The increasing pH of the WS-BrC solution increased its optical absorption. However, this study revealed that the light absorption properties of brown carbon emitted from commonly used biomasses were varied significantly.

Optimization of a Low Volume Extraction Method to Determine Polycyclic Aromatic Hydrocarbons in Aerosol Samples

This work describes the optimization of an extraction method for the determination of polycyclic aromatic hydrocarbons (PAHs) and their nitro- and oxy-PAH derivatives in atmospheric particulate matter (PM) samples, and demonstrates that this method is also effective for the determination of levoglucosan. The optimization of the extraction solvents was performed using a three-component mixture design with the solvents dichloromethane, methanol, and acetonitrile. The number of extractions, volume of solvent, and duration of extraction in an ultrasonic bath were optimized using a full factorial design followed by a central composite design. The analyses were performed by gas chromatography coupled with mass spectrometry. The optimized conditions of the method were three extractions using 4.0 ml of acetonitrile, with ultrasonication for 34 min. The proposed method presented good linearity (r &amp;gt; 0.990) and acceptable precision for low (100 ng ml−1, RSD: 1–16%), medium (300 ng ml−1, RSD: 1–19%), and high (500 ng ml−1, RSD: 2–16%) concentrations of PAHs. The limits of quantification for different PAHs ranged from 10 to 50 ng ml−1, which were suitable for atmospheric PM. Assessment of the method using sample matrix spiking/recovery assays, as well as use of a reference method, showed good recoveries for levoglucosan and for most of the PAHs and their derivatives, except for the most volatile compounds, which were lost during the evaporation of the solvent. The results for PM samples extracted by the optimized method and the reference method were in good agreement. The proposed method required 97% less solvent than the reference method, shortened the analysis time by 85%, and proved to be accurate and precise for the determination of at least 27 PAHs and their derivatives present in PM samples collected with a low-volume sampler.

Characterization of atmospheric aerosols in the Antarctic region using Raman Spectroscopy and Scanning Electron Microscopy

The non-destructive spectroscopic characterization of airborne particulate matter (PM) was performed to gain better knowledge of the internal structures of atmospheric aerosols at the particle level in the Antarctic region, along with their potential sources. PM and soil samples were collected during the 2016–2017 austral summer season at the surroundings of the Spanish Antarctic Research Station “Gabriel de Castilla” (Deception Island, South Shetland Islands). PM was deposited in a low-volume sampler air filter. Raman spectroscopy (RS) and Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) were used to determine the elemental and molecular composition of the individual aerosol and soil particles. Filter spectra measured by these techniques revealed long-range atmospheric transport of organic compounds (polystyrene and bacteria), local single and cluster particles made of different kinds of black carbon (BC), exotic minerals (polyhalite, arcanite, niter, ammonium nitrate, syngenite and nitrogen, phosphorus, and potassium (NPK) fertilizer), and natural PM (sea salts, silicates, iron oxides, etc.). In addition to the filter samples, forsterite and plagioclase were discovered in the soil samples together with magnetite. This is the first report of the presence of a microplastic fiber in the Antarctic air. This fact, together with the presence of other pollutants, reflects that even pristine and remote regions are influenced by anthropogenic activities.

Detection of SARS-CoV-2 in the indoor air of intensive care unit (ICU) for severe COVID-19 patients and its surroundings: considering the role of environmental conditions.

There is ambiguity about the airborne transmission of the SARS-CoV-2. While a distance of 6 feet is considered a safe physical distance, new findings show that the virus can be transmitted more than that distance and cause infection. In hospitals, this may cause the virus to be transmitted from the treatment wards of COVID-19 patients to adjacent wards and infect medical staff, non-COVID-19 patients, and patient companions. The aim of this study was to investigate the presence of coronavirus in the air of ICU and adjacent wards. The low volume sampler (LVS) with two separate inlets for PM2.5 and PM10 was applied to collect indoor air of intensive care unit (ICU) with confirmed COVID- 19 patients and its surroundings. The samples were collected on 0.3μ PTFE filter fitted to the holder. Sampling was done at flow rate of 16.7 l/min for 24 h. The SRAS-CoV-2 virus was isolated using a SinaPure™ Virus Extraction Kit (SINACLON, Iran). The presence of SARS-CoV-2 genome was assessed using a commercially available SARS-CoV-2 Test Kit (Pishtaz-Iran), according to the manufacturer’s instructions using One Step plus Real-Time PCR system tool (Applied Biosystems, USA). A total of sixteen samples were taken, and the positive test rate for SRAS-CoV-2 was 12.5 % (2/16). All samples from surrounding (rest room and hallway) were negative, but two air samples from indoor of ICU (next to the patient bed and nursing station) were found to be positive. The results support the possibility of transmitting the SRAS-CoV-2 through the air at a greater distance than what is known as a safe physical distance. Therefore, in addition to maintaining a safe physical distance, other precautions including wearing a face mask, preventing air recirculation, and maximizing the use of natural ventilation should be considered, especially in crowded and enclosed environments.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-021-16010-x.

Short-Term Particulate Matter, Ultrafine Particles, and Blood Pressure among Children of the CorPuScula Study in Munich, Germany

BACKGROUND AND AIM: Short-term changes in particulate matter (PM) have been linked to blood pressure, but limited evidence exists on effects among children and for ultrafine particle (UFP) exposures. METHODS: We used data from 50 children (ages 6-10) in the German CorPuScula study, in which children attended up to 30 school health examinations in 2001 and 2002. Systolic and diastolic blood pressure (SBP and DBP, respectively; mmHg) were collected at each examination after children had rested for at least 5 minutes. PM10 (diameter ≤10 µm; µg/m3) and PM2.5 (diameter ≤2.5 µm; µg/m3) levels were measured at school using a low volume sampler for the entire study period, and UFPs (n/mL) were measured for six months using a particle counter. All exposures were evaluated for same-day working-hours (9:00-21:00) as well as one- and two-day lags, with UFPs also assessed for the 1-, 3-, 12-, and 24-hours prior to examination. Associations between air pollutants and blood pressure were evaluated using mixed linear regression models with a random participant intercept and adjusted for weekday as well as study day and physiological equivalent temperature index using natural cubic splines. Multipollutant models were conducted adjusting for centrally-monitored NO2. RESULTS:For the PM data (nobs=1,079; average 22 observations/child), median daily PM2.5 levels were 12.7 µg/m3. In the UFP data (nobs=420; average 8 observations/child), median daily UFP exposures were 21,544 particles/mL. We observed positive associations between PM and SBP that attenuated slightly upon adjustment for NO2, with strongest associations for 2-day lags (e.g., 1.45 mmHg [95% Confidence Interval: 0.78, 2.11] increase in SBP per 13.4 µg/m3 increase in PM2.5). PM10 was weakly inversely associated with DBP. No associations between UFP exposures and either outcome were apparent. CONCLUSIONS:While positive associations were observed between PM and SBP, we observed no evidence that UFP exposure influences blood pressure in children. KEYWORDS: Children's environmental health, Short-term exposure, Air pollution, Cardiovascular diseases, Multi-pollutant

Consistent determination of the heating rate of light-absorbing aerosol using wavelength- and time-dependent Aethalometer multiple-scattering correction

Accurate and temporally consistent measurements of light absorbing aerosol (LAA) heating rate (HR) and of its source apportionment (fossil-fuel, FF; biomass-burning, BB) and speciation (black and brown Carbon; BC, BrC) are needed to evaluate LAA short-term climate forcing. For this purpose, wavelength- and time-dependent accurate LAA absorption coefficients are required. HR was experimentally determined and apportioned (sources/species) in the EMEP/ACTRIS/COLOSSAL-2018 winter campaign in Milan (urban-background site). Two Aethalometers (AE31/AE33) were installed together with a MAAP, CPC, OPC, a low volume sampler (PM2.5) and radiation instruments. AE31/AE33 multiple-scattering correction factors (C) were determined using two reference systems for the absorption coefficient: 1) 5-wavelength PP_UniMI with low time resolution (12 h, applied to PM2.5 samples); 2) timely-resolved MAAP data at a single wavelength. Using wavelength- and time-independent C values for the AE31 and AE33 obtained with the same reference device, the total HR showed a consistency (i.e. reproducibility) with average values comparable at 95% probability. However, if different reference devices/approaches are used, i.e. MAAP is chosen as reference instead of a PP_UniMI, the HR can be overestimated by 23–30% factor (by both AE31/AE33). This became more evident focusing on HR apportionment: AE33 data (corrected by a wavelength- and time-independent C) showed higher HRFF (+24 ± 1%) and higher HRBC (+10 ± 1%) than that of AE31. Conversely, HRBB and HRBrC were −28 ± 1% and −29 ± 1% lower for AE33 compared to AE31. These inconsistencies were overcome by introducing a wavelength-dependent Cλ for both AE31 and AE33, or using multi-wavelength apportionment methods, highlighting the need for further studies on the influence of wavelength corrections for HR determination.Finally, the temporally-resolved determination of C resulted in a diurnal cycle of the HR not statistically different whatever the source- speciation- apportionment used.