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Computational Intelligence and... 2022Dust pollution in construction sites is an invisible hazard that is often ignored as a nuisance. Regulatory and engineering control methods are predominantly used for...
Dust pollution in construction sites is an invisible hazard that is often ignored as a nuisance. Regulatory and engineering control methods are predominantly used for its mitigation. To control dust, dust-generating activities and their magnitudes need to be established. While researchers have comprehensively studied dust emissions of construction work, prediction of dust concentrations based on work phases and climatic conditions is still lacking. To overcome the above knowledge gap, this article selected two construction stages of a project to monitor dust generation using the HXF-35 dust sampler. Based on the collected data, dust emission characteristics of these two stages are studied, and dust emission characteristics under multiple pollution sources are analyzed. Based on the results, a BP neural network model is built to perform simulations of dust emission concentrations in different work areas and predict construction dust concentrations under different conditions. Except few, the majority of the work areas monitored have exceeded the allowable upper limit of TSP concentration stipulated by relevant standards. In addition, dust emission differences of work areas are pronounced. The results verified that the BP neural network dust concentration prediction model is feasible to be used to predict dust concentration changes in different work faces under different climate conditions and to provide a scientific base for pollution control. This study provides several practical solutions where the prediction of dust concentrations at designated work areas will allow construction companies early warning to implement mitigation measures before it becomes a serious health hazard. In addition, it provides an opportunity to re-evaluate those hazardous work in the light of these revelations. The outcome of this study is both original and useful for both construction companies and regulatory agencies. It can better predict the concentration of construction dust in different operating areas and different weather conditions and provide a guide for the prevention and control of construction dust.
Topics: Air Pollutants; Air Pollution; Dust; Environmental Monitoring
PubMed: 35845895
DOI: 10.1155/2022/7349001 -
Journal of Occupational and... Sep 2022Resurgence of coal mine dust lung diseases in the central Appalachian region of the United States and elsewhere has spurred a range of efforts to better understand...
Resurgence of coal mine dust lung diseases in the central Appalachian region of the United States and elsewhere has spurred a range of efforts to better understand respirable coal mine dust (RCMD) exposures and sources. Thermogravimetric analysis (TGA) of RCMD samples can enable the dust mass to be fractionated into three main components: coal, non-carbonate minerals, and carbonates. These are expected to approximate, respectively, the three primary dust sources in many underground mines: the coal seam being mined, the surrounding rock strata (i.e., typically dominated by non-carbonate minerals) being drilled or mined along with the coal, and the rock dust products (i.e., typically made from carbonate-rich limestone or dolostone) being applied in the mine to mitigate explosibility hazards. As proof of concept, TGA was applied to respirable dust samples that were laboratory-generated from real source materials representing 15 mines. Except in the case of two mines, compositional results were generally consistent with expectations. TGA was also applied to RCMD samples collected in standard locations of 23 mines (including the 15 mines represented by the dust source materials). Results showed significantly different compositions with respect to sampling location and geographic region (i.e., within and outside of central Appalachia). To further interpret the RCMD results, a simple source apportionment model was built using the dust compositions yielded from the source materials analysis. Model results indicated that, on average, about twice as much dust was sourced from mining into rock strata than from mining the target coal seam. This finding is particularly important for mines extracting relatively large amounts of rock along with the coal or for mines that frequently encounter high-silica rock strata.
Topics: Coal; Coal Mining; Dust; Minerals; Occupational Exposure; United States
PubMed: 35853145
DOI: 10.1080/15459624.2022.2100409 -
PloS One 2022Coal dust is the main pollutant in coal mining areas. Such pollutants easily diffuse and are difficult to monitor, which increases the cost of environmental pollution...
Coal dust is the main pollutant in coal mining areas. Such pollutants easily diffuse and are difficult to monitor, which increases the cost of environmental pollution control. Remote sensing technology can be used to dynamically monitor mining areas at a low cost, and thus, this is a common means of mining area management. According to the spectral characteristics of various ground objects in remote sensing images, a variety of remote sensing indexes can be constructed to extract the required information. In this study, the Wucaiwan open-pit coal mine was selected as the study area, and the Enhanced Coal Dust Index (ECDI) was established to extract the coal dust pollution information for the mining area. A new mining area pollution monitoring method was developed, which can provide technical support for environmental treatment and mining planning in Zhundong. The results of this study revealed the following: (1) Compared with the normalized difference coal index, the ECDI can expand the difference between the spectral information about the coal dust and the surrounding features, so it has a significant recognition ability for coal dust information. (2) From 2010 to 2021, the coal dust pollution in the study area initially increased and then decreased. With the continued exploitation of the coal mines in the study area, the coal dust pollution area increased from 14.77 km2 in 2010 to 69.49 km2 in 2014. After 2014, the local government issued various environmental pollution control policies, which had remarkable results. The coal dust pollution area decreased to 36.85 km2 and 17.85 km2 in 2018 and 2021, respectively. (3) There was a great deal of pollution around mines and roads, around which the pollution was more serious. Various factors, such as wind, coal type, and the mining, processing, and transportation modes, affect the distribution of the coal dust pollution.
Topics: China; Coal; Coal Mining; Dust; Environmental Monitoring; Environmental Pollutants; Environmental Pollution; Minerals
PubMed: 35395022
DOI: 10.1371/journal.pone.0266517 -
Molecules (Basel, Switzerland) Sep 2022Ageing processes of vehicle catalytic converters inevitably lead to the release of Pt and Pd into the environment, road dust being the main sink. Though Pt and Pd are...
Ageing processes of vehicle catalytic converters inevitably lead to the release of Pt and Pd into the environment, road dust being the main sink. Though Pt and Pd are contained in catalytic converters in nanoparticulate metallic form, under environmental conditions, they can be transformed into toxic dissolved species. In the present work, the distribution of Pt and Pd between dissolved, nanoparticulate, and microparticulate fractions of Moscow road dust is assessed. The total concentrations of Pt and Pd in dust vary in the ranges 9-142 ng (mean 35) and 155-456 (mean 235) ng g, respectively. The nanoparticulate and dissolved species of Pt and Pd in dust were studied using single particle inductively coupled plasma mass spectrometry. The median sizes of nanoparticulate Pt and Pd were 7 and 13 nm, respectively. The nanoparticulate fraction of Pt and Pd in Moscow dust is only about 1.6-1.8%. The average contents of dissolved fraction of Pt and Pd are 10.4% and 4.1%, respectively. The major fractions of Pt and Pd (88-94%) in road dust are associated with microparticles. Although the microparticulate fractions of Pt and Pd are relatively stable, they may become dissolved under changing environmental conditions and, hence, transformed into toxic species.
Topics: Dust; Environmental Monitoring; Palladium; Platinum; Rhodium; Vehicle Emissions
PubMed: 36144840
DOI: 10.3390/molecules27186107 -
Water Science and Technology : a... Apr 2024Leaking manhole covers add inflow to sanitary sewer systems. These are the most accessible components of the sewer system, and so potentially the cheapest to repair or...
Leaking manhole covers add inflow to sanitary sewer systems. These are the most accessible components of the sewer system, and so potentially the cheapest to repair or modify, to reduce inflow. There is, however, very little data regarding manhole cover leakage available to evaluate the cost-benefit of such an approach, and there is no field data. So, a multi-year field study of inflow was conducted. Two-hundred and fifty manholes in New York City and surrounding towns were tested. A key field observation in this study was that a dust and grit seal typically built up between the cover and the rim. This seal had a big impact on leakage rates. This made testing in-situ a necessity, and the test method had to preserve this seal. Due to the presence of the dust and grit seal, approximately 80% of the manholes tested showed no leakage. A further 15% had slow leaks. Only 5% had significant leaks.
Topics: New York City; Dust; Waste Disposal, Fluid
PubMed: 38678404
DOI: 10.2166/wst.2024.118 -
The Science of the Total Environment Sep 2023Particle number size distribution in dust plumes and its modification as the plume travels over the Anatolia were investigated by measuring particle number size...
Particle number size distribution in dust plumes and its modification as the plume travels over the Anatolia were investigated by measuring particle number size distributions at two stations: one located on the Mediterranean coast of Turkey and the other on the Anatolian plateau. Clustering of backtrajectories revealed six trajectory clusters at the Marmaris station and nine clusters at the Ankara station. Cluster 6 in Marmaris and clusters 6, 7 and 9 in Ankara stations had the potential to transport Saharan dust to stations. Concentration of particles with D ≤ 1 μm increased during dust events in the Ankara station, but decreased at the Marmaris station. Higher PM concentrations during the non-dust period at the Marmaris station were attributed to the dominance of secondary particle formation on PM concentrations. Occurrence of sea salt episodes at the Marmaris station and anthropogenic episodes at the Ankara station affects the distribution of episodes. If different types of episodes are not differentiated and all episodes are considered as dust, it can lead to misleadingly high dust episodes in winter. Six Saharan dust episodes were sequentially intercepted first at the Marmaris and then at the Ankara stations. These episodes were used to study how dust size distribution is modified as the plume travels from the Mediterranean coast to central Anatolia. On the average, travel time between the two stations is 1-2 days. Particle number concentrations in 1 μm ≤ D ≤ 110 μm size range were consistently high at the Ankara station, indicating that local sources play a role in modifying the number size distribution as the plume travels over the Anatolian plateau.
Topics: Dust; Air Pollutants; Environmental Monitoring; Africa, Northern; Seasons; Particle Size; Particulate Matter
PubMed: 37301395
DOI: 10.1016/j.scitotenv.2023.164646 -
Annals of Work Exposures and Health Jun 2023Cement belongs to the most used building materials. Clinker is the major constituent of cement, and it is believed that the strong increase of pH after hydration of...
OBJECTIVES
Cement belongs to the most used building materials. Clinker is the major constituent of cement, and it is believed that the strong increase of pH after hydration of clinker minerals is responsible for the observed decline in lung function of cement production workers. Information on clinker exposure at workplaces in the cement production industry is scarse. The aims of this study are to determine the chemical composition of thoracic dust and to quantify workplace exposure to clinker in cement production.
METHODS
The elemental composition of 1250 personal thoracic samples collected at workplaces in 15 plants located in 8 different countries (Estonia, Greece, Italy, Norway, Sweden, Switzerland, Spain, Turkey) was determined by inductively coupled plasma optical emission spectrometry (ICP-OES), separately for water- and acid-soluble fraction. Positive matrix factorization (PMF) was used to determine the contribution of different sources to the dust composition and to quantify the clinker content in 1227 of the thoracic samples. In addition, 107 material samples were analysed to facilitate interpretation of the factors obtained by PMF.
RESULTS
The median thoracic mass concentrations varied for individual plants between 0.28 and 3.5 mg/m3. PMF with 8 water-soluble and 10 insoluble (i.e., acid-soluble) element concentrations yielded a five-factor solution: Ca, K, Na sulfates; silicates; insoluble clinker; soluble clinker-rich; and soluble Ca-rich. The clinker content of the samples was calculated as sum of the insoluble clinker and soluble clinker-rich factors. The median clinker fraction of all samples was 45% (range 0-95%), and varied between 20% and 70% for individual plants.
DISCUSSION
The 5-factor solution of PMF was selected on the basis of several mathematical parameters recommended in the literature as well as the mineralogical interpretability of the factors. In addition, interpretation of the factors was supported by the measured apparent solubility of Al, K, Si, Fe, and to a lesser extent Ca in material samples. The total clinker content obtained in the present study is considerably lower than estimates based on the Ca concentrations in a sample, and somewhat lower than estimates based on Si concentrations after selective leaching with a methanol/maleic acid mixture. The clinker abundance in workplace dust of one plant investigated in the present contribution was also estimated in a recent study by electron microscopy, and the good agreement between both studies gives confidence in the results of PMF.
CONCLUSIONS
The clinker fraction in personal thoracic samples could be quantified from the chemical composition by positive matrix factorization. Our results allow for further epidemiological analyses of health effects in the cement production industry. As these estimates are more accurate for clinker exposure than aerosol mass, stronger associations with respiratory effects are expected if clinker is the main cause of these effects.
Topics: Humans; Occupational Exposure; Dust; Construction Materials; Workplace; Industry
PubMed: 36866437
DOI: 10.1093/annweh/wxad011 -
Environmental Science and Pollution... Sep 2023The utilization of solar photovoltaic (PV) power generation represents a highly promising technological solution for addressing environmental challenges and energy...
The utilization of solar photovoltaic (PV) power generation represents a highly promising technological solution for addressing environmental challenges and energy crises. Dust deposition on the front and back surfaces of solar bifacial PV panels greatly decreases the optical performance and power generation. In this study, the dust deposition characteristics and mechanism of solar bifacial PV panels are investigated using the CFD-DEM method. The effects of the dust deposition rate on the output characteristics of bifacial PV panels are discussed. The research results show that the particle deposition behaviors on the back and front surfaces of bifacial PV panels are influenced by the deposition and separation forces at the left or right inlets. The dust deposition rate of windward surfaces can be 1.48-7.60 times that of the leeward surfaces of bifacial PV panels. The particle motion trajectories on the windward and leeward sides can be mainly divided into five and three kinds, respectively. The dust deposition rate of bifacial PV panels increases when the air inlet velocity decreases and the particle size and concentration and relative humidity increase. The open circuit voltage and short circuit current of bifacial PV panels decreased by 26.7% and 16.4%, respectively, when the dust deposition rate increases by 45.8%. The attenuation rate of the maximum output power of PV panels has a positive linear correlation with the dust deposition rate, as shown in Eq. 22. The bifacial PV panels have better output characteristics than the mono-facial PV panels with consideration of dust deposition.
Topics: Dust; Solar Energy; Particle Size
PubMed: 37644273
DOI: 10.1007/s11356-023-29518-1 -
Chemosphere Jan 2022Exposure to phthalates poses adverse health impacts to human beings. In this study, we analyzed 7 phthalates in dust samples, which were collected with vacuum cleaner...
Exposure to phthalates poses adverse health impacts to human beings. In this study, we analyzed 7 phthalates in dust samples, which were collected with vacuum cleaner from 40 to 31 residences in Beijing in summer and winter, respectively. The major phthalates (median concentration in the summer and winter, respectively) were DiBP (55 and 40 ng/mg), DnBP (99 and 30 ng/mg) and DEHP (795 and 335 ng/mg). The concentrations were significantly influenced by season and residence time of house dust. The concentrations of phthalates in dust on plastic surfaces were highest, followed by those on wooden and fabric surfaces. The dust-air partition coefficients (K) were calculated: the median values were 0.13, 0.02 and 5.62 m/mg in the summer and 0.06, 0.018 and 0.76 m/mg in the winter for DiBP, DnBP and DEHP, respectively. A comparison with K* at equilibrium state suggested that partition between air and dust deviated from equilibrium state in both seasons. The results also revealed that dust-phthalates in the summer may completely originate from source materials via direct transfer and external physical process; while dust-phthalates in the winter may come from both air (via partition) and source material (via direct transfer and external physical process). The influence of temperature on dust-phthalate concentrations differed by season, owing to different origin of dust-phthalates in two seasons. Polar organic components in dust, which are products of reactions between O and unsaturated hydrocarbons in dust, likely played an important role in fate and transport of phthalates. The presence of them resulted in the significant associations between dust-phthalate concentrations and air humidity in the summer. Moreover, the impacts of indoor PM concentrations, traffic conditions surrounding residence, household lifestyle and number of occupants were also observed. The mechanisms behind those observations were discussed.
Topics: Air Pollution, Indoor; China; Dust; Environmental Exposure; Humans; Phthalic Acids
PubMed: 34352541
DOI: 10.1016/j.chemosphere.2021.131703 -
Environmental Science and Pollution... Jan 2022To solve issues of low consolidation strength, poor dust suppression effect, and secondary pollution of the current coal dust suppressors, a greener and...
To solve issues of low consolidation strength, poor dust suppression effect, and secondary pollution of the current coal dust suppressors, a greener and higher-consolidation-strength composite dust suppressor was synthesized by the radical polymerization of xanthan gum (XG) as the graft substrate, methyl acrylate (MA), and vinyl acetate (VAc) as the graft monomers. Taking compressive strength as the main optimization index and viscosity and surface tension as the secondary indices, the optimum ratio of MA:VAc was 3:5 and the optimum solid content was 2%. Experiments reveal that the prepared dust suppressant can naturally infiltrate into coal to form a hard solidified layer. At a wind speed of 10 m/s, the solidified layer still maintained structural integrity, indicating that the dust suppressant exhibits a good dust fixation effect. The dust suppressant can not only maintain relatively stable performance for a period of time but also degrade naturally. Furthermore, molecular dynamics simulation reveals not only the interaction mechanism between coal molecules and the dust suppressor but also the wetting mechanism of the dust suppressor. Experimental and simulation results reveal that as a multifunctional dust suppressor with excellent performance, the as-prepared dust suppressor demonstrates the immense potential for the control of coal dust. Graphical abstract.
Topics: Coal; Coal Mining; Dust; Polysaccharides, Bacterial
PubMed: 34476699
DOI: 10.1007/s11356-021-16258-3