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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. [ABSTRACT FROM AUTHOR]

This report provides a review of several measurement studies and campaigns focusing on road dust resuspension (RDS), which is becoming an important source of ambient particulate matter (PM) concentrations. There is a growing requirement from stakeholders, policy makers and scientists for gathering additional data around RDS, since there is a lack of well-established methodologies or those developed for measuring or modelling this source of emissions are not very recent. Moreover, conventional inventory methodologies are not available for this source of emissions, and it is not yet covered in the UK's National Atmospheric Emissions Inventory (NAEI) neither in the inventory guidebooks at European level. Based on the available literature and models, this paper also seeks to provide some preliminary considerations whether an approach can be tailored for application in air quality models used for modelling ambient PM concentrations in the UK in a consistent manner and demonstrated using a state-of-art air quality modelling tool, namely RapidAir®. The impact of including resuspension emissions on roadside concentrations was modelled in a UK case study with the greatest increases in modelled road PM10 concentrations observed on or near the road surface. The paper concludes with recommendations for longer-term implementation of the proposed improvements such as investigation of the temporal effects of RDS on PM levels; of the influence of different type of tyre materials and mixture (e.g., composition) and designs (e.g., shape, dimensions and tread); and influence of different existing pavements or of new road surface types. [ABSTRACT FROM AUTHOR]

In this paper, individual particle analysis by automated scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX) was used to assess the size-resolved information of composition, size distribution, complex refractive index, and mixing state of mineral dust aerosol particles collected using different passive and active samplers. In the study, over 120,000 particles from 53 samples were analyzed. Results show that dust particles are the dominating mineral particle type during this campaign, comprising different classes of silicates, Si-rich (quartz-like), Ca-rich (calcite-like), CaMg-rich (dolomite-like), and CaS-rich (gypsum-like). The results also show that there is no significant difference in composition between suspended and deposited dust particles. By using the particle composition, the size-resolved complex refractive index of dust particles was calculated. The real part of the refractive index varied between 1.71 and 1.53 for wavelengths in the range of 370 to 950 nm. The imaginary part of the refractive index, determined mostly by iron oxide, varied between 3.28 × 10 − 4 and 7.11 × 10 − 5 for wavelengths ranging from 250 nm to 1640 nm. In addition, the refractive index values showed a slight decrease with increasing particle size. We also analyzed the potential for buffering of the acid mobilization of iron by other dust compounds. For particles which contain both iron (Fe) and (unprocessed) calcium (Ca), acids that are able to dissolve insoluble Fe particles can react with the Ca particles before reacting with Fe, but eventually, with longer processing time, the Fe particles could be processed. By analyzing the ratio of sulfate mass to the total aerosol mass of individual particles, the mixing state of sulfate particles to the total dust particles was investigated. The analysis showed that the finer dust particles were associated with higher content of sulfate, while the coarse dust particles correspond to lower sulfate contents, revealing that only fine mode sulfate is more internally mixed with mineral dust aerosol particles. [ABSTRACT FROM AUTHOR]

The melting behavior of glaciers on and around the Tibetan Plateau is strongly influenced by their albedo. In this paper, we report continuous observations made on the Qiangtang (QT) No. 1 Glacier, located in the central Tibetan Plateau, during its 2013–2015 melting seasons. Surface snow on the QT No. 1 Glacier mainly had a dust content less than 600 ppm and a black carbon (BC) content less than 10 ppb. A strong negative correlation was observed between albedo and dust content up to a threshold concentration of 1000 ppm, although albedo remained constant when dust concentrations increased above this value. The radii of snow particles showed a log-normal distribution that had a mean value of ~500 μm, but maximum and minimum values of 2539 μm and 40 μm, respectively. Snow density showed a normal distribution with a total range of 193–555 kg/m3, although most snow had a density of 400 kg/m3. Snow, ice, and aerosol radiative (SNICAR) simulations showed that dust and BC in the surface snow of the QT No. 1 Glacier reduced the snow and ice albedo by 5.9% and 0.06%, respectively, during the ablation season in 2015; however, the simulated particle impact was greater than the albedo reduction measured from field data. We interpret that dust has played a significantly more important role in melting of the QT No. 1 Glacier than BC over the study period, which is mainly due to the scarcity of human activities in the region and the low concentration of BC being produced. [ABSTRACT FROM AUTHOR]

Turkey is located in the heart of complex transition geography between Eurasia and the Middle East. In the grand scheme, the so-called eastern Mediterranean Basin is located almost in the middle of the dusty belt, and is a hot spot of climate change. The downstream location of dust-carrying winds from close desert sources reveals Turkey as an open plane to particulate matter exposure throughout the year. In order to clarify this phenomenon, this paper aims to determine the desert dust climatology of Turkey via CALIPSO onboard Lidar. This prominent instrument enables us to understand clouds, aerosols and their types, and related climatic systems, with its valuable products. In this study, a 9-year CALIPSO-derived pure dust product dataset was formed to explain horizontal and vertical distributions, transport heights and case incidences. The results indicated that the pure dust extinction coefficient increased as the location shifted from west to east. Moreover, in the same direction of west to east, the dominant spring months changed to summer and autumn. Mountain range systems surrounding Anatolia were the main obstacles against lofted and buoyant dust particles travelling to northern latitudes. Even if high ridges accumulated mass load on the southern slopes, they also enabled elevated particles to reach the ground level of the inner cities. [ABSTRACT FROM AUTHOR]

Dust storms and wildfires occur frequently in south-eastern Australia. Their effects on the ecology, environment and population exposure have been the focus of many studies recently. Dust storms do not emit ground-sequestered carbon, but wildfires emit significant quantities of carbon into the atmosphere. However, both natural events promote phytoplankton growth in water bodies because carbon, and other trace elements such as iron, deposit on the surface water of oceans. Carbon dioxide is reabsorbed by phytoplankton via photosynthesis. The carbon balance cycle due to dust storms and wildfires is not well known. Recent studies on the carbon emission of the 2019–2020 summer wildfires in eastern Australia indicated that this megafire event emitted approximately 715 million tonnes of CO2 (195 Tg C) into the atmosphere from burned forest areas. This study focusses on the association of dust storms and wildfires in southeastern Australia with phytoplankton growth in the Tasman Sea due to the February 2019 dust storm event and the 2019–2020 Black Summer wildfires. Central Australia and western New South Wales were the sources of the dust storm emission (11 to 16 February 2019), and the Black Summer wildfires occurred along the coast of New South Wales and Victoria (from early November 2019 to early January 2020). The WRF-Chem model is used for dust storm simulation with the AFWA (Air Force Weather Agency of the US) dust emission version of the GOCART model, and the WRF-Chem model is used for wildfire simulation with FINN (Fire Emission Inventory from NCAR) emission data. The results show the similarities and differences in the deposition of particulate matter, phytoplankton growth and carbon reabsorption patterns in the Tasman Sea from these events. A higher rate of deposition of PM2.5 on the ocean surface corresponds to a higher rate of phytoplankton growth. Using the WRF-Chem model, during the 5-day dust storm event in February 2019, approximately ~1230 tons of total dust was predicted to have been deposited in the Tasman Sea, while ~132,000 tons of PM10 was deposited in the early stage of the wildfires from 1 to 8 November 2019. [ABSTRACT FROM AUTHOR]

The mechanism of aerosol pollution transport remains highly elusive owing to the myriad of influential factors. In this study, ground station data, satellite data, ground-based LiDAR remote sensing data, sounding data, ERA5 reanalysis and a backward trajectory model were combined to investigate the formation process and optical properties of winter aerosol pollution in Beijing and surrounding areas. The analysis of ground station data shows that compared to 2019 and 2021, the pandemic lockdown policy resulted in a decrease in the total number of pollution days and a decrease in the average concentration of particulate matter in the Beijing area in 2020. The terrain characteristics of the Beijing-Tianjin-Hebei (BTH) made it prone to northeast and southwest winds. The highest incidence of aerosol pollution in Beijing occurs in February and March during the spring and winter seasons. Analysis of a typical heavy aerosol pollution process in the Beijing area from 28 February to 5 March 2019 shows that dust and fine particulate matter contributed to the primary pollution; surface air temperature inversion and an average wind speed of less than 3 m/s were conducive to the continuous accumulation of pollutants, which was accompanied by the oxidation reaction of NO2 and O3, forming photochemical pollution. The heavy aerosol pollution was transmitted and diffused towards the southeast, gradually eliminating the pollution. Our results provide relevant research support for the prevention and control of aerosol pollution. [ABSTRACT FROM AUTHOR]

The transport and deposition of atmospheric particulate matter have attracted significant attention recently due to the increasing frequency of extreme disaster events, such as dust storms, volcanic eruptions, and extensive forest fires. The size distribution of the transported material and the conditions of the land–air interface are dominant factors in comprehending the detrimental potential of atmospheric particulate matter. However, it is still a challenge to understand the mechanism of dust deposition, especially over complex terrain. In an effort to investigate the deposition characteristics of particles over complex terrain, a series of experiments were conducted in a multifunctional environmental wind tunnel. The results show that the wind speed directly above the top of the mild slope model is significantly greater than that in the steep slope model, which indicates that a steep slope has a greater blocking effect on wind fields. At low wind speeds, the average wind speed at the top of the mild slope model is 17.8% higher than that at the top of the steep slope model, and at high wind speeds the average wind speed at the top of the mild slope model is 8.6% higher than that at the top of the steep slope model. The influence trend of the steep slope model and the combination model is basically the same, with both decreasing first and then increasing with the direction of wind velocity. The amount of surface deposition is greatly affected by the location of the feeding point and the microscale characteristics of the surface. In the steep slope model, the deposition is mainly distributed on the windward side, while the leeward side has a small amount of deposition. In the mild slope model, particles are deposited not only on the windward side, but also on the leeward side. The average rate of decline in deposition flux in the steep slope model is 88.4% and 75.1% in the mild slope model. The use of the combination model reduces the particle concentration at the back end compared with the single model. In three different models, the deposition on the windward side was shown to be significantly greater than that on the leeward side of the model. Our work increases understanding of the deposition of coarse dust particles over complex terrain and provides basic data for improving the accuracy of large-region particle transport and deposition simulations. [ABSTRACT FROM AUTHOR]

Air pollution in the Metropolitan Area of São Paulo (MASP), Brazil, is a serious problem and is strongly affected by local sources. However, atmosphere column composition in MASP is also affected by biomass burning aerosol (BB). Understanding the impacts of aerosol particles, from both vehicles and BB, on the air quality and climate depends on in-depth research with knowledge of some parameters such as the optical properties of particles and their chemical composition. This study characterized fine particulate matter (PM2.5) from July 2019 to August 2020 in the eastern part of the MASP, relating the chemical composition data obtained at the surface and columnar optical parameters, such as aerosol optical depth (AOD), Ångström Exponent (AE), and single-scattering albedo (SSA). According to the analyzed data, the mean PM2.5 concentration was 18.0 ± 12.5 µg/m3; however, daily events exceeded 75 times the air quality standard of the World Health Organization (15 µg/m3). The mean black carbon concentration was 1.8 ± 1.5 µg/m3 in the sampling period. Positive matrix factorization (PMF) identified four main sources of aerosol: heavy vehicles (42%), followed by soil dust plus local sources (38.7%), light vehicles (9.9%), and local sources (8.6%). AOD and AE presented the highest values in the dry period, during which biomass burning events are more frequent, suggesting smaller particles in the atmosphere. SSA values at 440 nm were between 0.86 and 0.94, with lower values in the winter months, indicating the presence of more absorbing aerosol. [ABSTRACT FROM AUTHOR]

The physical mechanisms associated with heat waves (HWs) are well known in the midlatitudes but still under-documented in the Sahel. Specifically, the role of anthropogenic and natural changes in tropospheric aerosols regarding HWs remains an issue to address. Our study focuses on the characterisation of the dusty HWs in the Sahel, which generally occur from March to June. The goal is to reinforce or invalidate the assumption proposed in previous studies recently carried out in southern Europe and according to which mineral dust may locally change irradiance at the surface, thus atmospheric temperatures at 2 m, intensifying the HW. The work is carried out in three steps: (i) detect and describe the HW over the 2003–2014 period based on maximum daily 2-m temperatures (T m a x ) from ERA-Interim reanalyses; (ii) characterise the dust optical properties during the HW using the Deep Blue aerosols products from MODIS (Moderate Resolution Imaging Spectroradiometre): the Aerosol Optical Depth at 550 nm (AOD 550 ), the Angstrom Exponent (AE 440 − 870 ) and the Single Scattering Albedo at 412 nm (SSA 412 ) as a proxy of quantity over atmospheric column, size and absorption of aerosols, respectively; (iii) relate HW intensity to the aerosol conditions during the HW. Over the 12-year study period, 14 HWs are detected when T m a x exceeds the 90th percentile (P90). The HWs are dusty with AOD 550 ranging between 0.46 and 1.17 and all the dust types are absorbent with a SSA 412 value of 0.93 (round to hundredths). The HW classification according to aerosol conditions gave three HWs: Type 1 corresponds to Pure Dust Situation (PDS with AE 440 − 870 = 0.1), Type 2 and Type 3 are associated with Mixed Situation (MS) with dominance of Coarse Particles (CP with AE 440 − 870 = 0.35) and Fine Particles (FP with AE 440 − 870 = 0.65), respectively. The main result obtained is that the intensity of the dusty HW, computed as the difference between daily T m a x and its P90 (T m a x −P90)), is higher for Type 1 HW (+1.1 °C) in the case of the most absorbent aerosol situation (SSA 412 = 0.931). A non-significant difference between Type 2 and Type 3 especially for temperature (+0.5 °C and +0.4 °C, respectively) and SSA (0.938 and 0.935, respectively) is observed and, during these mixing situations, the HWs are less intense than those during the PDS. Finally, the analysis of two huge Type 1 HWs in 2007 and 2010 shows that dust mass concentrations at the surface were particularly high, up to 214 μg/m3 on average. These findings enable us to assess that highly absorbent and concentrated pure dust situations observed in spring in the Sahel may have a potential warming effect at the surface. [ABSTRACT FROM AUTHOR]

This study investigated the sensitivity of the positive matrix factorization (PMF) model using concentrations of PM2.5-bound elements in Windsor, Ontario, Canada. Five scenarios were devised to assess impacts of input data on source identification, source contributions, and model performance. The study found that the model outcomes and performance were not sensitive to data below method detection limits (MDLs) being replaced with ½ MDLs, nor whether brown carbons (BrCs) data were excluded. By analyzing two episodic events individually, unique factors of fireworks and mineral dust were identified for each of the two episodes. Moreover, PMF model performance was improved greatly for event markers of the episodes and elements with less variability in concentration when compared with the base case scenario. Excluding the two episodes from the entire dataset had little impact on factor identification and source contributions but improved the model performance for three out of twelve elements unique to the two episodes. Overall, the PMF model outcomes and performance were sensitive to percentages of concentrations below MDLs and element concentrations with large variability due to high concentrations observed in episodes. Our findings are useful for dealing with data below MDLs and episodic events in conducting future PMF source apportionment of PM2.5-bound elements. [ABSTRACT FROM AUTHOR]

This study presents the source apportionment of coarse-mode particulate matter (PM10) extracted by 3 receptor models (PCA/APCS, UNMIX, and PMF) at semi-urban sites of the Indian Himalayan region (IHR) during August 2018–December 2019. In this study, water-soluble inorganic ionic species (WSIIS), water-soluble organic carbon (WSOC), carbon fractions (organic carbon (OC) and elemental carbon (EC)), and trace elements of PM10 were analyzed over the IHR. Nainital (62 ± 39 µg m−3) had the highest annual average mass concentration of PM10 (average ± standard deviation at 1 σ), followed by Mohal Kullu (58 ± 32 µg m−3) and Darjeeling (54 ± 18 µg m−3). The annual total ∑WSIIS concentration order was as follows: Darjeeling (14.02 ± 10.01 µg m−3) > Mohal-Kullu (13.75 ± 10.21 µg m−3) > Nainital (10.20 ± 6.30 µg m−3), contributing to 15–30% of the PM10 mass. The dominant secondary ions (NH4+, SO42−, and NO3−) suggest that the study sites were strongly influenced by anthropogenic sources from regional and long-range transport. Principal component analysis (PCA) with an absolute principal component score (APCS), UNMIX, and Positive Matrix Factorization (PMF) were used for source identification of PM10 at the study sites of the IHR. All three models showed relatively similar results of source profiles for all study sites except their source number and percentage contribution. Overall, soil dust (SD), secondary aerosols (SAs), combustion (biomass burning (BB) + fossil fuel combustion (FFC): BB+FFC), and vehicular emissions (VEs) are the major sources of PM10 identified by these models at all study sites. Air mass backward trajectories illustrated that PM10, mainly attributed to dust-related aerosols, was transported from the Thar Desert, Indo-Gangetic Plain (IGP), and northwestern region of India (i.e., Punjab and Haryana) and Afghanistan to the IHR. Transported agricultural or residual burning plumes from the IGP and nearby areas significantly contribute to the concentration of carbonaceous aerosols (CAs) at study sites. [ABSTRACT FROM AUTHOR]

Over the last decades, the impact of mineral dust from African deserts on human health and climate has been of great interest to the scientific community. In this paper, the climatological analysis of dusty events of the past 20 years in the Caribbean area has been performed using a particulate approach. The focus is made on June 2020 extreme event dubbed "Godzilla". To carry out this study, different types of data were used (ground-based, satellites, model, and soundings) on several sites in the Caribbean islands. First, the magnitude of June 2020 event was clearly highlighted using satellite imagery. During the peak of this event, the value of particulate matter with an aerodynamic diameter of less than 10 μ m ( P M 10 ) reached a value 9 times greater than the threshold recommended by the World Health Organization in one day. Thereafter, the P M 10 , the aerosol optical depth, and the volume particle size distribution analyses exhibited their maximum values for June 2020. We also highlighted the exceptional characteristics of the Saharan air layer in terms of thickness and wind speed for this period. Finally, our results showed that the more the proportion of particulate matter with an aerodynamic diameter of less than 2.5 μ m ( P M 2.5 ) in P M 10 increases, the more the influence of sea salt aerosols is significant. [ABSTRACT FROM AUTHOR]

Following population growth and rapid urbanization, West African cities have become major sources of anthropogenic pollution. Additionally, Saharan dust has had a significant impact, representing a potentially toxic mix of sources for the population. This study characterizes the atmospheric composition and its sources in two African capitals, Bamako, Mali and Dakar, Senegal. TSP, PM10 and PM2.5 samples were collected during the dry season in 2009 when pollution levels were high: chemical analysis included organic carbon (OC), elemental carbon (EC), ions, and metals. PM2.5 and PM10 concentrations were 5–10 times and 3–8 times higher, respectively, than the 2005 WHO 24 h standards. Using PCA and PMF methodologies, five sources were identified in each city. In Bamako, traffic (motor vehicles and resuspended road dust) was the prevailing source of PM2.5 and PM10, accounting for 47% and 45%, respectively. Crustal dust was the second most important source (24–30%), followed by solid fuel combustion (16–13%) and secondary aerosols (10–16%). In Dakar, the following sources of PM2.5 and PM10 are identified: traffic (49%), mineral dust (16–25%), sea salts (15–20%) and industries (10–11%). Our study provides crucial information about the historical change in source characteristics in these two African cities, which can help for future mitigation strategies. [ABSTRACT FROM AUTHOR]

In this study, a combination of ground-based particulate matter measurements in synergy with space-borne CALIOP lidar recordings, meteorological observations, and reanalysis models have been used to study atmospheric air pollution over Amman, Jordan. The measurement was conducted over a 24-month period spanning from January 2018 to the end of December 2019. The CALIOP aerosol profiles and aerosol layer products version 4.21, level 2, with 5 km horizontal resolution were used to evaluate the vertical structure of the atmospheric constituent over the Amman region. The particle depolarization ratio (PDR) was extracted from CALIOP recordings and has been utilized to classify the type of atmospheric aerosols. This method reveals that the atmosphere above Amman mostly contains three different aerosol types including coarse-mode dust, fine-mode dust (polluted dust), and non-dust aerosols (pollution). Aerosols with 0 < δ p ≤ 0.075 are categorized as pollution, aerosols with 0.075 < δ p ≤ 0.20 as polluted dust, and aerosols with 0.20 < δ p ≤ 0.40 are classified as dust. Both the one- and two-step POlarization-LIdar PHOtometer Networking (POLIPHON) approaches have been applied to the CALIOP aerosol profile product to retrieve the vertical profile of the optical and micro-physical properties of each aerosol type. Lofted-layer top heights and layer thickness in the atmosphere above Amman during the study period were also extracted from the CALIOP aerosol layer products. The highest frequency of occurrence was observed for layers with a top height of 0.5 to 2.5 km with a second smaller peak at 3.5 km. The maximum frequency of the lofted layers (40% of cases) were observed with layer thickness below 0.5 km. For layers with a top height lower than 500 m above ground level, the atmosphere was mostly impacted by polluted dust and pollution aerosols. On the other hand, for layers with a top height above 2500 m agl, the atmosphere was contaminated by depolarizing dust particles. [ABSTRACT FROM AUTHOR]

Icelandic topsoil sediments, as confirmed by numerous scientific studies, represent the largest and the most important European source of mineral dust. Strong winds, connected with the intensive cyclonic circulation in the North Atlantic, induce intense emissions of mineral dust from local sources all year and carry away these fine aerosol particles for thousands of kilometers. Various impacts of airborne mineral dust particles on local air quality, human health, transportation, climate and marine ecosystems motivated us to design a fully dynamic coupled atmosphere–dust numerical modelling system in order to simulate, predict and quantify the Icelandic mineral dust process including: local measurements and source specification over Iceland. In this study, we used the Dust Regional Atmospheric Model (DREAM) with improved Icelandic high resolution dust source specification and implemented spatially variable particle size distribution, variable snow cover and soil wetness. Three case studies of intense short- and long-range transport were selected to evaluate the model performance. Results demonstrated the model's capability to forecast major transport features, such as timing, and horizontal and vertical distribution of the processes. This modelling system can be used as an operational forecasting system, but also as a reliable tool for assessing climate and environmental Icelandic dust impacts. [ABSTRACT FROM AUTHOR]

Indoor house dust is a blend of organic and inorganic materials, upon which diverse microbial communities such as viruses, bacteria and fungi reside. Adequate moisture in the indoor environment helps microbial communities multiply fast. The outdoor air and materials that are brought into the buildings by airflow, sandstorms, animals pets and house occupants endow the indoor dust particles with extra features that impact human health. Assessment of the health effects of indoor dust particles, the type of indoor microbial inoculants and the secreted enzymes by indoor insects as allergens merit detailed investigation. Here, we discuss the applications of next generation sequencing (NGS) technology which is used to assess microbial diversity and abundance of the indoor dust environments. Likewise, the applications of NGS are discussed to monitor the gene expression profiles of indoor human occupants or their surrogate cellular models when exposed to aqueous solution of collected indoor dust samples. We also highlight the detection methods of dust allergens and analytical procedures that quantify the chemical nature of indoor particulate matter with a potential impact on human health. Our review is thus unique in advocating the applications of interdisciplinary approaches that comprehensively assess the health effects due to bad air quality in built environments. [ABSTRACT FROM AUTHOR]

Dust is the collection of fine particles of solid matter, and it is a major issue of atmospheric pollution. Dust particles are becoming the major pollutants of the urban environment due to hyperbolic manufacturing and automobile pollution. These atmospheric pollutants are not only hazardous for human beings, but they also affect tree growth, particularly in urban environments. This study was designed to examine the changes in morphological and physiological traits of three tree species seedlings (Eucalyptus camaldulensis, Conocarpus erectus, and Bombax ceiba) in response to different dust types. In a pot experiment under controlled conditions, three-month-old seedlings of selected trees species were subjected to four treatments of dust: T1 = controlled; T2 = wood dust; T3 = soil dust; and T4 = carbon dust. During the whole experiment, 10 g/plant/dose was applied in 8 doses with a one-week interval. The results depicted that the growth was the maximum in T1 (control) and the minimum in T4 (carbon dust). In our findings, B. ceiba performed better under the same levels of dust pollution as compared with the other two tree species. The B. ceiba tree species proved to be the most tolerant to dust pollution by efficiently demolishing oxidative bursts by triggering SOD, POD, and CAT under different dust types compared to controlled conditions. Stomatal conductance, photosynthetic rate, and transpiration rate were negatively influenced in all three tree species in response to different dust applications. Based on the findings, among these three tree species, B. ceiba is recommended for dust polluted areas followed by E. camaldulensis and Conocarpus erectus due to their better performance and efficient dust-foraging potential. [ABSTRACT FROM AUTHOR]

Dust emission from the Gobi desert is one of the major sources of global atmospheric aerosols. However, the main factors affecting dust emission from Gobi remain poorly understood. In this paper, field wind tunnel experiments were performed atop the Mogao Grottoes to determine the variation characteristics of the vertical dust flux (F) of particulate matter less than 10 μm (PM10) for Gobi surfaces with different dust content and wind speeds under external sand supply. The results demonstrate that F obeyed a power function with increasing friction velocity ( U * ), and increased exponentially with the increasing surface dust content (C). The index of n-value in the formula F∝ U * n is taken in the range of 2.02–2.63 under the surface of 27.3–47.3% dust content (<100 µm), and the dust emission rate was significantly enhanced when the surface dust content exceeded approximately 37%. This study indicates that wind force is the primary dynamic condition affecting Gobi dust emission, and that surface dust content is a significant factor in determining the quantity of dust emission. Furthermore, the contribution of wind force to PM10 emission is greater than the surface dust content, and the higher the height, the greater the weight of friction velocity. [ABSTRACT FROM AUTHOR]

Mineral dust is one of the most important aerosols over the world, affecting health and climate. These mineral particles are mainly emitted over arid areas but may be long-range transported, impacting the local budget of air quality in urban areas. While models were extensively used to study a single specific event, or make a global analysis at coarse resolution, the goal of our study is to simultaneously focus on several affected areas--Europe, North America, Central Asia, east China and the Caribbean area--for a one-month period, March 2014, avoiding any parameter fitting to better simulate a single dust outbreak. The simulation is performed for the first time with the hemispheric version of the CHIMERE model, with a high horizontal resolution (about 10 km). In this study, an overview of several simultaneous dust outbreaks over the Northern Hemisphere is proposed to assess the capability of such modeling tools to predict dust pollution events. A quantitative and qualitative evaluation of the most striking episodes is presented with comparisons to satellite data, ground based particulate matter and calcium measurements. Despite some overestimation of dust concentrations far from emission source areas, the model can simulate the timing of the arrival of dust outbreaks on observational sites. For instance, several spectacular dust storms in the US and China are rather well captured by the models. The high resolution provides a better description and understanding of the orographic effects and the long-range transport of dust plumes. [ABSTRACT FROM AUTHOR]

To evaluate the characteristics of atmospheric particle retention by plant leaves during the tourism season in Buddhism-based scenic areas, plants distributed in the core area of the Mount Wutai scenic area were selected for study: Populus davidiana (Po. davidiana), Rosa hugonis Hemsl. (R. hugonis), Betula platyphylla Suk. (B. platyphylla), Rosa xanthina Lindl. (R. xanthina), Periploca sepium Bunge (Pe. sepium), Spiraea salicifolia L. (S. salicifolia), Vitex negundo var. Heterophylla (V. negundo var. heterophylla) and Pinus tabuliformis Carrière (Pi. tabuliformis). Before rain, the atmospheric suspended particle-retaining weight of the plant leaves varied in the range of 6.95 ± 1.55 (Pi. tabuliformis) to 38.60 ± 18.32 mg/cm² (Po. davidiana); the light shaded areas caused by particles on leaves were in the range of 7.25 ± 0.04 (Pi. tabuliformis) to 126.50 ± 6.66 cm²/leaf (Po. davidiana); and the atmospheric particle-retaining horizontal density of leaves varied in the range of 110 ± 2 (Pi. tabuliformis) to 255 ± 11 per cm² (Po. davidiana). After rain, the atmospheric suspended particle-retaining quality of plant leaves varied in the range of 0.65 ± 0.23 (Pi. tabuliformis) to 3.50 ± 1.83 mg/cm² (Po. davidiana); the light shaded areas by particles on leaves were in the range of 4.26 ± 0.02 (Pi. tabuliformis) to 45.96 ± 2.42 cm²/leaf (Po. davidiana); and the atmospheric particle-retaining horizontal density of leaves was in the range of 97 ± 2 (Pi. tabuliformis) to 147 ± 7 per cm² (Po. davidiana). The broad-leaved plants, particularly Po. davidiana, R. hugonis and B. platyphylla, were appropriate species for purification of atmospheric particles. Plants with lower dust-retention abilities than the above three species (e.g., R. xanthina, Pe. sepium, S. salicifolia and V. negundo var. heterophylla) could be alternative plants for purification. However, the needle-leaved plant Pi. tabuliformis was not recommended as a tree species for purification of atmospheric particles in the core area of the Mount Wutai scenic area. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM) is object of particular attention due to its health effects. It is currently regulated by adopting PM2.5 as an indicator to control anthropogenic combustion emissions. Therefore, it is crucial to collect aerosol samples representative of such sources, without including PM from natural sources. Thus, a clean separation between coarse and fine mode aerosol should be set. With this purpose, aerosol size mass distribution was taken in the aerodynamic diameter range from 0.5 to 10 µm. In comparison with a base scenario, characterized by local pollution sources, three case studies were considered, involving desert dust advection, sea salt advection and forest fire aerosol from a remote area. In the base scenario, PM2.5 represented a suitable fine-mode indicator, whereas it was considerably affected by coarse PM in case of desert dust and sea salt aerosol advection. Such interference was considerably reduced by setting the fine/coarse separation at 1.0 µm. Such separation underrepresented fine PM from forest fire long-range transport, nonetheless in the case studies considered, PM1 represented the best indicator of fine aerosol since less affected by coarse natural sources. The data presented clearly support the results from other studies associating the health effects of PM2.5 to PM1, rather than to PM1–2.5. Overall, there is a need to reconsider PM2.5 as an indicator of fine atmospheric aerosol. [ABSTRACT FROM AUTHOR]

Air pollution associated with suspended particles has become a significant concern in Vietnam recently. The study aimed to (1) investigate dust sources; (2) measure concentration levels of Total Suspended Particulate (TSP), Particulate Matter (PM) fractions; (3) identify silica levels and the correlation with respirable particles at a cement grinding plant in Vietnam. A total of 312 samples (52 TSP, 160 PMs) at 13 processes were measured using the direct-reading dust meter. The silica composition was analyzed in a certified laboratory using the X-ray fluorescence (XRF) technique. SPSS version 26 for Window was used to analyze the data. The operations of the cement grinding plant created multiple dust sources from the jetty to the cement dispatch process. The TSP levels ranged 0.06–38.24 mg m−3, and 40.38% (n = 21) TSP samples exceeded the Permissible Exposure Limit (PEL) for an 8-h working shift. Besides that, there was a wide range and significant concentration levels of PMs in the cement processes. The levels of PMs were PM1 (0.00–0.06 mg m−3), PM2.5 (0.01–0.83 mg m−3), PM4 (0.02–4.59 mg m−3), PM7 (0.03–16.94 mg m−3), and PM10 (0.04–26.85 mg m−3). The highest mean levels of PMs factions were measured at the pre-grinding process. The inefficient operation of the dust collector contributed a significant factor to the dust dispersion in this process. The silica's mean (SD) composition in respirable dust was 20.4% (0.86) and was not significantly different amongst the processes. There was a significant correlation between the levels of respirable dust and silica exposure in the cement grinding plant (r = 0.99). The improvement of indoor air quality is needed to prevent health effects on cement workers. [ABSTRACT FROM AUTHOR]

Air filters for general ventilation have mainly been used to control the concentration of indoor particulate matter. In this study, the pressure differential, test dust capacity, quality factor and operating life of class F8 pleat–plate and multi-bag type chemical fiber filters were evaluated using an air filter performance test system. The results showed that the resistance increase rate of multi-bag filter (0.49 Pa/g·(cm/s)) was lower than that of pleat–plate filter (1.94 Pa/g·(cm/s)), the quality factor of the multi-bag filter was lower than that of pleat–plate filter, and the dust capacity of the multi-bag filter was much higher than that of the pleat–plate filter. The operating life of the multi-bag filter was 8 times as that of the pleat–plate filter with the measured PM2.5 of outdoor. The energy consumption of the pleat–plate filter was 2.2 times that of the multi-bag filter. Analyzing the electron microscope photos after dust loading, the dust depth of pleat–plate filter into filter material was thinner than that of multi-bag filter. The research results could provide data support for the design optimization and selection of ventilation filters and the treatment of the particulate matter in indoor environments. [ABSTRACT FROM AUTHOR]

Road dust is an important source of resuspended particulate matter (PM) but information is lacking on the chemical composition of the ultrafine particle fraction (UFP; <0.1 µm). This study investigated metal concentrations in UFP isolated from the "dust box" of sweepings collected by the City of Toronto, Canada, using regenerative-air-street sweepers. Dust box samples from expressway, arterial and local roads were aerosolized in the laboratory and were separated into thirteen particle size fractions ranging from 10 nm to 10 µm (PM10). The UFP fraction accounted for about 2% of the total mass of resuspended PM10 (range 0.23–8.36%). Elemental analysis using ICP-MS and ICP-OES revealed a marked enrichment in Cd, Cr, Zn and V concentration in UFP compared to the dust box material (nano to dust box ratio ≥ 2). UFP from arterial roads contained two times more Cd, Zn and V and nine times more Cr than UFP from local roads. The highest median concentration of Zn was observed for the municipal expressway, attributed to greater volumes of traffic, including light to heavy duty vehicles, and higher speeds. The observed elevated concentrations of transition metals in UFP are a human health concern, given their potential to cause oxidative stress in lung cells. [ABSTRACT FROM AUTHOR]

Minimetrò (MM) is a ropeway public mobility system that has been in operation in the city of Perugia for about ten years to integrate with urban mobility and lighten vehicular traffic in the historic city center. The purpose of this work was to evaluate the impact of MM as a source of pollutants in the urban context, and the exposure of people in the cabins and the platforms along the MM line. These topics have been investigated by means of intensive measurement and sampling campaigns performed in February and June 2015 on three specific sites of the MM line representative of different sources and levels of urban pollution. Stationary and dynamic measurements of particle size distribution, nanoparticle and black carbon aerosol number and mass concentrations measurements were performed by means of different bench and portable instruments. Aerosol sampling was carried out using low volume and high-volume aerosol samplers, and the samples nalysed by off-line methods. Results show that MM is a considerable source of atmospheric particulate matter having characteristics very similar to those of the common urban road dust in Perugia. In the lack of clear indications on road dust effect, the contribution of MM to the aerosol in Perugia cannot be neglected. [ABSTRACT FROM AUTHOR]

Road dust (RD) resuspension is one of the main sources of particulate matter in cities with adverse impacts on air quality, health, and climate. Studies on the variability of the deposited PM10 fraction of RD (RD10) have been limited in Latin America, whereby our understanding of the central factors that control this pollutant remains incomplete. In this study, forty-one RD10 samples were collected in two Andean cities (Bogotá and Manizales) and analyzed for ions, minerals, and trace elements. RD10 levels varied between 1.8–45.7 mg/m2, with an average of 11.8 mg/m2, in Bogotá and between 0.8–26.7 mg/m2, with an average of 5.7 mg/m2, in Manizales. Minerals were the most abundant species in both cities, with a fraction significantly larger in Manizales (38%) than Bogotá (9%). The difference could be explained mainly by the complex topography and the composition of soil derived from volcanic ash in Manizales. The volcanic activity was also associated with SO4−2 and Cl−. Enrichment factors and principal component analysis were conducted to explore potential factors associated to sources of RD10. Elements such as Cu, Pb, Cr, Ni, V, Sb, and Mo were mainly associated with exhaust and non-exhaust traffic emissions. [ABSTRACT FROM AUTHOR]

Heatwaves are an extreme meteorological event in which affected populations may also be exposed to deteriorated air quality conditions due to the increase in air pollutant concentrations, such as PM10 (particulate matter < 10 µg/m3). In order to identify heatwaves (1973–2019) in the region of Faro (Algarve) during the hot season (April–September), the Excess Heat Factor (EHF) index was applied. The Mann–Kendall test revealed an upward trend in three heatwave metrics in Faro, and the trend of accumulated heat load (EHF load) was also positive as would be expected, but its signal was not statistically significant. An inventory of North African dust events (2006–2019) was made, and their simultaneous occurrence with heatwaves was assessed, pointing to only 20% of dust events of the Sahara occurring simultaneously with heatwave days. A cluster analysis was conducted on daily geopotential height fields at 850 hPa level over the 2006–2019 period, and four distinct patterns were identified as the most prominent synoptic circulations promoting both heatwave conditions and North African dust over the Algarve. [ABSTRACT FROM AUTHOR]

This study evaluates the health risks related to heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Se, Zn, and metalloid As) in the indoor dust samples of total suspended particles (TSP) and particles with diameter <1 μm (PM1). The samples were collected during 5-day periods during the spring and winter seasons in the Upper Silesia region, Poland. The highest concentration among determined trace elements revealed Fe. The greatest concern expressed the concentration of carcinogenic Cd in PM1 (from 6.7 to 9.7 ng/m3), exceeding the permissible value 5 ng/m3 (for PM10). The carcinogenic and non-carcinogenic health risks were assessed for three exposure pathways (inhalation, ingestion, and dermal contact) for preschool children. None of the single trace elements obtained the Hazard Quotient Index (HQ > 1) or carcinogenic risks above the upper acceptable limit (1 × 10−4). However, the cumulative HQ values (ΣHQ) for three exposure pathways were greater than the safe level. The highest cumulative non-carcinogenic risk presented the TSP in rural kindergartens (2.0 × 10−4). In the same location as the TSP, the highest carcinogenic risk was also observed (9.1 × 10−4). High carcinogenic risks (>10−4) were found for the ingestion pathway of TSP inside urban and rural kindergartens and of PM1 in urban ones. A comparative evaluation shows that the health risks of trace elements in airborne particles in Polish kindergartens bring high risk. [ABSTRACT FROM AUTHOR]

Sharp GP2Y1010 dust sensors are increasingly being used within distributed sensing networks and for personal monitoring of exposure to particulate matter (PM) pollution. These dust sensors offer an easy-to-use solution at an excellent price point; however, the sensors are known to offer limited dynamic range and poor limits of detection (L.O.D.), often >15 μg m−3. The latter figure of merit precludes the use of this inexpensive line of dust sensors for monitoring PM2.5 levels in environments within which particulate pollution levels are low. This manuscript presents a description of the fabrication and circuit used in the Sharp GP2Y1010 dust sensor and reports several effective strategies to minimize noise and maximize limits of detection for PM. It was found that measurement noise is primarily introduced within the photodiode detection circuitry, and that electromagnetic interference can influence dust sensor signals dramatically. Through optimization of the external capacitor and resistor used in the LED drive circuit—and the inter-pulse delay, electromagnetic shielding, and data acquisition strategy—noise was reduced approximately tenfold, leading to a projected noise equivalent limit of detection of 3.1 μg m−3. Strategies developed within this manuscript will allow improved limits of detection for these inexpensive sensors, and further enable research toward unraveling the spatial and temporal distribution of PM within buildings and urban centers—as well as an improved understanding of effect of PM on human health. [ABSTRACT FROM AUTHOR]

Road dust is one of the primary sources of particulate matter which has implications for air quality, climate and health. With the aim of characterizing the emissions, in this study, a bottom-up approach of county level emission inventory from paved road dust based on field investigation was developed. An inventory of high-resolution paved road dust (PRD) emissions by monthly and spatial allocation at 1 km × 1 km resolution in Harbin in 2016 was compiled using accessible county level, seasonal data and local parameters based on field investigation to increase temporal-spatial resolution. The results demonstrated the total PRD emissions of TSP, PM10, and PM2.5 in Harbin were 270,207 t, 54,597 t, 14,059 t, respectively. The temporal variation trends of pollutant emissions from PRD was consistent with the characteristics of precipitation, with lower emissions in winter and summer, and higher emissions in spring and autumn. The spatial allocation of emissions has a strong association with Harbin's road network, mainly concentrating in the central urban area compared to the surrounding counties. Through scenario analysis, positive control measures were essential and effective for PRD pollution. The inventory developed in this study reflected the level of fugitive dust on paved road in Harbin, and it could reduce particulate matter pollution with the development of mitigation strategies and could comply with air quality modelling requirements, especially in the frigid region of northeastern China. [ABSTRACT FROM AUTHOR]

Air pollution is of major concern throughout the world and the use of modeling tools to analyze and forecast the pollutant concentrations in complex orographic areas remains challenging. This work proposes an exhaustive framework to analyze the ability of models to simulate the air quality over the French Alps up to 1.2 km resolution over Grenoble and the Arve Valley. The on-line coupled suite of models CHIMERE-WRF is used in its recent version to analyze a 1 month episode in November–December 2013. As expected, an improved resolution increases the concentrations close to the emission areas and reduced the negative bias for Particulate Matter that is the usual weakness of air quality models. However, the nitrate concentrations seem overestimated with at the same time an overestimation of surface temperature in the morning by WRF. Different WRF settings found in the literature are tested to improve the results, particularly the ability of the meteorological model to simulate the strong thermal inversions in the morning. Wood burning is one of the main contributor of air pollution during the period ranging from 80 to 90% of the Organic Matter. The activation of the on-line coupling has a moderate impact on the background concentrations but surprisingly a change of Particulate Matter (PM) concentrations in the valley will affect more the meteorology nearby high altitude areas than in the valley. This phenomenon is the result of a chain of processes involving the radiative effects and the water vapor column gradients in complex orographic areas. At last, the model confirms that the surrounding glaciers are largely impacted by long range transport of desert dust. However, in wintertime some outbreaks of anthropogenic pollution from the valley when the synoptic situation changes can be advected up to the nearby high altitude areas, then deposited. [ABSTRACT FROM AUTHOR]

The Mediterranean area is a climate-change hotspot because of the natural and anthropogenic pollution pressure. The presence of natural aerosols, such as dust, influences solar radiation and contributes to the detection, in storm episodes, of significant concentrations of PM10 in Southern Italy, where generally fresh and clean air is due to local circulation, and particulate matter concentrations are very low. We present the results of medium-term observations (2015–2019) at Lamezia Terme GAW (Global Atmospheric Watch) Regional Observatory, with the purpose of identifying the dust incursion events by studying the aerosol properties in the site. To achieve this goal, the experimental data, collected by several instruments, have been also correlated with the large-scale atmospheric patterns derived by the ERA5 reanalysis dataset, in order to study the meteorological conditions that strongly influence dust outbreaks and their spatio-temporal behavior. An intense dust-outbreak episode, which occurred on 23–27 April 2019, was chosen as a case study; a detailed analysis was carried out considering surface and column optical properties, chemical properties, large-scale pattern circulation, air-quality modeling/satellite products, and back-trajectory analysis, to confirm the capability of the modeled large-scale atmospheric fields to correctly simulate the conditions mainly related to the desert dust-outbreak events. [ABSTRACT FROM AUTHOR]

Haul traffic on earthworks runways during construction works is an important factor of dust emission. Compacted soils surface become progressively degraded as the number of wheels passing increases. Fine particles are then segregated from the soil surface and lifted when the shear stress generated by the flow above the surface increases, leading to the worsening of air quality and reduction of visibility. Laboratory tests were performed to assess dust emissions on traffic degraded soils. Mixtures of kaolin clay and sand were compacted using a laboratory roller compactor and were degraded using a vehicle simulator. Models describing the evolutions of soil degradation and Particle Size Distribution (PSD) during traffic were established. Then, the velocity profiles above each soil sample were obtained in a wind tunnel. The experimental results were analyzed to determine the Reynolds shear stresses generated by the turbulence of the flow. PSD, degradation and stresses were implemented in the Convective Turbulent Dust Emission (CTDE) model to estimate the dust emission flux of the soils for several passes of the wheel. A comparison between results from the model and field measurements underlines that turbulence is not the main contributor to dust emissions when a vehicle is in motion. [ABSTRACT FROM AUTHOR]

Desert dust outbreaks may affect air quality. This study estimates the importance of African dust contribution to the PM10 and PM2.5 concentrations observed in rural regional background sites in Portugal. Desert dust contribution is evaluated by two different approaches: A measurement-approach methodology based on the monthly moving 40th percentile, and a model-approach methodology based on WRF-CHIMERE simulations, whose performance is also assessed within this work. Several desert dust episodes affected atmospheric aerosols in the planetary boundary layer over Portugal during 2016. Their intensity was variable, with at least two events (21–22 February and 27–28 October) contributing to exceedances to the PM10 daily limit value defined in the European Air Quality Directive. African dust contributions obtained for the year 2016 with the measurement-approach methodology are higher than the ones simulated by WRF-CHIMERE. Contributions to PM10 and to PM2.5 concentrations range from 0 to 90 µg m−3 and from 0 to 30 µg m−3, respectively, in most of the regions and days. Caution must be employed when using measurement-approach methodologies to quantify dust contributions to PM levels when forest fires occur simultaneously with the long-range transport of desert dust, as happened in August 2016. [ABSTRACT FROM AUTHOR]

Air pollution has many adverse effects on health and is associated with an increased risk of mortality. Desert dust outbreaks contribute directly to air pollution by increasing particulate matter concentrations. We investigated the influence of desert dust outbreaks on air quality in Santa Cruz de Tenerife, a city located in the dust export pathway off the west coast of North Africa, using air-quality observations from a six-year period (2012–2017). During winter intense dust outbreaks PM 10 mean (24-h) concentrations increased from 14 μ g m − 3 to 98 μ g m − 3 , on average, and PM 2. 5 mean (24-h) concentrations increased from 6 μ g m − 3 to 32 μ g m − 3 . Increases were less during summer outbreaks, with a tripling of PM 10 and PM 2. 5 daily mean concentrations. We found that desert dust outbreaks reduced the height of the marine boundary layer in our study area by >45%, on average, in summer and by ∼25%, on average, in winter. This thinning of the marine boundary layer was associated with an increase of local anthropogenic pollution during dust outbreaks. NO 2 and NO mean concentrations more than doubled and even larger relative increases in black carbon were observed during the more intense summer dust outbreaks; increases also occurred during the winter outbreaks but were less than in summer. This has public health implications; local anthropogenic emissions need to be reduced even further in areas that are impacted by desert dust outbreaks to reduce adverse health effects. [ABSTRACT FROM AUTHOR]

Residential dust is recognized as a major source of environmental contaminants, including polycyclic aromatic hydrocarbons (PAHs) and plasticizers, such as phthalic acid esters (PAEs). A sampling campaign was carried out to characterize the dust fraction of particulate matter with an aerodynamic diameter smaller than 10 µm (PM10), using an in situ resuspension chamber in three rooms (kitchen, living room, and bedroom) of four Spanish houses. Two samples per room were collected with, at least, a one-week interval. The PM10 samples were analyzed for their carbonaceous content by a thermo-optical technique and, after solvent extraction, for 20 PAHs, 8 PAEs and one non-phthalate plasticizer (DEHA) by gas chromatography-mass spectrometry. In general, higher dust loads were observed for parquet flooring as compared with tile. The highest dust loads were obtained for rugs. Total carbon accounted for 9.3 to 51 wt% of the PM10 mass. Plasticizer mass fractions varied from 5 µg g−1 to 17 mg g−1 PM10, whereas lower contributions were registered for PAHs (0.98 to 116 µg g−1). The plasticizer and PAH daily intakes for children and adults via dust ingestion were estimated to be three to four orders of magnitude higher than those via inhalation and dermal contact. The thoracic fraction of household dust was estimated to contribute to an excess of 7.2 to 14 per million people new cancer cases, which exceeds the acceptable risk of one per million. [ABSTRACT FROM AUTHOR]

With Changchun's economic development, atmospheric particulate pollution has become a significant challenge in Changchun. The spatiotemporal patterns of particulate matter emissions are an inherent characteristic for particulate matter emissions. By using hourly PM (particulate matter) mass concentration measured at 10 atmospheric automatic monitoring stations and meteorological parameters, the spatiotemporal distribution characteristics of particulate matter (PM10 and PM2.5) and its relationship with meteorological parameters of Changchun have been analyzed. Pollution pathways and source distribution were investigated using HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model and cluster analysis. Results indicated that the quarterly average PM2.5 and PM10 mass concentrations in Changchun were higher in the first quarter and the fourth quarter. PM concentrations observed in all seasons generally exhibited two peaks, at 07:00–10:00 and 21:00–23:00, with the exception of PM10 in spring. PM pollution was concentrated mainly in the central, northern, and western areas of Changchun in most seasons, mainly due to anthropogenic activities and soil dust transported outside the region. PM concentrations were negatively correlated with relative humidity and temperature. PM2.5 concentrations were negatively correlated with wind speed, while PM10 concentrations were positively correlated with wind speed. The results of backward trajectory clustered showed that the northwest airflow had the greatest impact on PM of Changchun, except summer. [ABSTRACT FROM AUTHOR]

Urban air quality is continuing to deteriorate. If we want to do something about this problem, we need to know the cause of the pollution. The big problem, not only in Europe, is the high concentrations of particulate matter (PM) in the urban environment. The origin of these particles can be different, including combustion, transport, industry, natural resources, etc. Particulate matter includes a large amount of the finest PM fractions, which can remain in the air for a long time, easily enter respiratory tracks, and damage human health. Particulate matter is also produced by the abrasion of different parts of roads and vehicle fleets and from resuspension road dust, which concerns matter with larger aerodynamic diameters. For this reason, we carried out a series of measurements at various measuring stations in Žilina, Slovakia, during different measuring seasons. The main objective was to find out the diversity of particulate matter sources in Žilina. The search for the particulate matter origin was carried out by particulate matter measurements, determination of the particulate matter fraction concentrations (PM10, PM2.5, and PM1), an investigation on the effect of secondary factors on the particulate matter concentrations, chemical analyses, and multivariate statistical analyses. Varied behavior of the particulate matter with respect to the measurement station and the measurement season was found. Differences in the concentrations of investigated chemical elements contained in the PM were found. Significant changes in the concentrations of particulate matter are caused not only by primary sources (e.g., road traffic in the city of Žilina), but mainly by the negative events (combination of air pollution sources and meteorological conditions). Maximum concentrations of particulate matter PM10 were measured during the winter season at the measuring station on Komenského Street: PM10 126.2 µg/m3, PM2.5 97.7 µg/m3, and PM1 90.4 µg/m3 were obtained using the gravimetric method. The coarse fraction PM2.5-10 was mainly represented by the chemical elements Mg, Al, Si, Ca, Cr, Fe, and Ba, and the fine fraction PM2.5 was represented by the chemical elements K, S, Cd, Pb, Ni, and Zn. Road transport as a dominant source of PM10 was identified from all measurements in the city of Žilina by using the multivariate statistical methods of principal component analysis (PCA) and factor analysis (FA). [ABSTRACT FROM AUTHOR]

In this study, we used the positive matrix factorization (PMF) model to evaluate the sources of ambient coarse particulate matter (PM) and their temporal variations in two sampling sites, i.e., a school dormitory and a retirement home, located in central Tehran. 24-h ambient PM samples were collected using low-volume air samplers from May 2012 to June 2013. The collected filters were analyzed for their chemical components, including water-soluble ions, metals, and trace elements, which were used as the input to the PMF model. Our results indicated annual averages of 45.7 ± 3.8 µg/m3 and 36.2. ± 4.0 µg/m3 for coarse PM at the School dormitory and Tohid retirement home, respectively. Moreover, higher ambient coarse PM mass concentrations were observed in the warm season (53.3 ± 5.8 µg/m3 for school dormitory and 43.1 ± 6.1 µg/m3 for Tohid retirement home) as opposed to the cold season (41.4 ± 4.7 µg/m3 for school dormitory and 28.7 ± 4.6 µg/m3 for Tohid retirement home). Our PMF analysis also identified road dust, soil, and industry, and atmospherically processed coarse PM as the three sources of ambient coarse PM in central Tehran. Road dust, soil, and industry were the major sources of ambient coarse PM, contributing respectively to 74 ± 9% and 19 ± 2% of the total coarse PM mass concentration, while atmospherically aged aerosols had a rather minimal contribution of 7 ± 1% to total coarse PM mass concentration. The temporal trends of the resolved factors also revealed higher contributions of road dust to total ambient coarse PM during warm season as opposed to cold season, due to the increased resuspension rate from road surfaces as a result of higher wind speeds, and temperatures, combined with lower relative humidity. Similarly, higher resuspension rate of mechanically originated particulates resulted in higher warm-season time contributions of the soil factor. Results of this study clearly revealed the key role of road dust and non-tail pipe emissions on ambient coarse PM mass concentrations in crowded areas of central Tehran, and have important implications on the potential health impacts that can be caused by these difficult to mitigate sources of coarse PM. [ABSTRACT FROM AUTHOR]