Article

Characterization of PM10 and PM2.5 Source Profiles of Fugitive Dust in Zhengzhou, China

January 2017
Aerosol and Air Quality Research 18(2)

DOI:10.4209/aaqr.2017.04.0132

Authors:

Nan Jiang

Zhengzhou University

Yuanqian Xu

Jinan University of Lebanon

Fei Yu

Zhengzhou University

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As a result of rapid urbanization, the road lengths and built-up areas in Zhengzhou are steadily expanding along with increasing fugitive dust emissions. Identifying the physical and chemical characteristics and the chemical profiles of fugitive dust is important in achieving effective atmospheric pollution management. In this study, soil dust, road dust (RD), building demolition dust, and cement (CE) were chosen as the research objects. A total of 94 dust samples were collected from 20 sites. PM2.5(particulate matter with diameter ≤ 2.5 µm) and PM10(particulate matter with diameter ≤ 10 µm) samples were obtained by using a re-suspension device and their physical and chemical properties were analyzed. The scanning electron microscopy of four types of dust particles showed that most of the dust particles presented an irregular shape. In terms of particle size distribution, the mass concentration of PM2.5accounted for less than 10% of the total PM10, whereas the number concentration of PM2.5accounted for more than 96% of the total number. Chemical component analysis revealed that crustal elements such as Al, Mg, Fe, and K were abundant in all samples, and they were the most abundant species in PM2.5and PM10in the reconstruction results. The percentage of NO3⁻in the RD sample was higher than that in the other three fugitive dust samples because of the influence of vehicles. Furthermore, the CE sample had higher SO42–and Ca²⁺percentages than the other three types of fugitive dust samples. Enrichment factor analysis showed that the significant enrichment of Cd and Ag was mainly caused by anthropogenic sources. The coefficients of divergence values between the profiles for different sites of dust ranged from 0.21 to 0.68, indicating the fugitive dust profiles from various sites mostly different. The chemical profiles of four dust sources obtained from this study is limited in Zhengzhou.

Sub-type source profiles of fine particles for fugitive dust and accumulative health risks of heavy metals: a case study in a fast-developing city of China

Article

Full-text available

May 2020
ENVIRON SCI POLLUT R

Sub-type source profiles for atmospheric fine particle (PM2.5) were still scare in China, which limited the accurate source identification of it. Fugitive dust (including road dust, soil dust, resuspended dust, and construction dust, etc.) was one type of the most important contributors to PM2.5 and its associated toxic metals held potential threaten to human health. The chemical compositions, sources, and health risks of sub-type fugitive dust deserved an investigation for further accurate control of particles and alleviating human health risks. A total of sixty-five fugitive dust samples were collected in Suzhou, a fast-developing city in southern China, including eleven sub-types of road dust (overpass, main street, collector street, and ordinary street), soil dust (farmland and tree lawn), resuspended dust (site types were corresponding to those of road dust), and construction dust (large construction sites). Chemical analysis of water-soluble ions, elements, and carbonaceous components was carried out to establish the sub-type source profiles of PM2.5 for fugitive dust. Results showed that crustal elements were the most abundant components of fugitive dust, and soil dust was less polluted by anthropogenic activities. High contents of OC and low contents of EC were found in all the eleven types of dust. Equivalent ratios of anions and cations indicated that the fugitive dust was obviously alkaline. The contents of OC and EC in the four types of road dust were higher than those in other types of dust, while there existed differences among the sub-types of road dust. The NO3−/SO42− ratios (0.03–0.09) implied that coal-burning and motor vehicle emission co-existed in Suzhou. Coefficient divergence (CD) values of eleven sub-type source profiles showed that there were certain differences among them, which suggested the possibility of sub-type source identification. Cluster analysis indicated the heavy metals in fugitive dust were mainly from crustal materials, metallurgical manufacturing, vehicle emissions, and industrial activities. The enrichment degree of heavy metals for the four types of road dust was also inconsistent. Heavy metals in road dust and soil dust posed a non-carcinogenic risk to children through direct ingestion, and the non-carcinogenic risk of direct intake of heavy metals was much higher than that of respiratory and skin contact. It was found that the accumulative health risks of heavy metals were higher in densely populated areas, traffic intensive areas, and industrial areas through the spatial analysis. This study firstly discussed the chemical compositions of PM2.5 for eleven sub-types of fugitive dust in a Chinese city and assessed the accumulative health risks of heavy metals, which could be a demonstration for further related researches.

Pollution Characterization, Source Identification, and Health Risks of Atmospheric-Particle-Bound Heavy Metals in PM10 and PM2.5 at Multiple Sites in an Emerging Megacity in the Central Region of China

Article

Jan 2018

Chemical Source Profiles and Toxicity Assessment of Urban Fugitive Dust PM2.5 in Guanzhong Plain, China

Article

Full-text available

Aug 2023

Urban fugitive dust is a significant contributor to atmospheric PM2.5 and a potential risk to humans. In 2019, both road dust and construction dust were collected from four cities, including Xi’an, Xianyang, Baoji, and Tongchuan, in Guanzhong Plain, China. Elements, water-soluble ions, and carbonaceous fractions were determined to establish the chemical source profile. High enrichment degrees of Se, Sc, Cl, and Zn in both road dust and construction dust indicated that the industrial system and energy consumption influenced Guanzhong Plain strongly. According to the coefficient of divergence, the two datasets within Xianyang and Tongchuan were similar. Combined with the chemical profile, road dust was affected by more stationary emission sources than construction dust in Xi’an, while biomass burning and vehicle exhaust contributed more to road dust than construction dust in Baoji. Moreover, the health risk of heavy metal was assessed, and corresponding influencing factors were identified. Road dust in all cities showed a non-negligible non-carcinogenic risk for children. Ingestion and inhalation were the main exposure pathways to which As and Co contributed the most, respectively. The land-use regression model revealed that the first-class road in a 100 m radius impacted all high-risk level metals, and the commercial building material and enterprises weakly influenced Co and Pb, respectively.

Physico-chemical properties and transboundary transport of PM2.5 in Bien Hoa City, Dong Nai Province, Southeastern Vietnam

Article

Full-text available

Dec 2022
ENVIRON SCI POLLUT R

Air pollution is one of the most concerning environmental issues, wherein PM2.5 concentration plays an important role. This study monitored and evaluated the PM2.5 concentration trends in Bien Hoa City, Dong Nai Province, Vietnam. Twenty 24-h PM2.5 samples were continuously collected during the rainy (15 Oct. to 25 Oct. 2021) and dry (19 Mar. to 29 Mar. 2022) seasons. The PM2.5 samples were analyzed by scanning electron microscopy to determine the surface pattern and size distributions were analyzed using ImageJ software. The water-soluble fractions of 15 trace metal(oid)s concentrations (Al, Cu, Ni, K, Ca, Co, Mn, Cr, As, Zn, Pb, Cd, Na, Fe, and Mg) bound to PM2.5 were analyzed by inductively coupled plasma-mass spectrometry. The results showed that the 24-h fine fraction PM2.5 concentrations were 24.1 ± 12.2 μg/m³ and 63.0 ± 18.7 μg/m³ in the rainy and dry seasons, respectively. The results indicate that the size distributions of the particles of 2.0–2.5 μm are minor, and the majority are ultrafine particles with aerodynamic diameter ≤ 1.0 μm. Overall, the mass concentration level of the water-soluble fraction of trace metal(oid)s in PM2.5 in the rainy season was higher than that in the dry season. Among these, Ca, K, and Na were the most abundant earth crustal elements in PM2.5 in the rainy and dry seasons, accounting for 85% and 41.2% of the total trace element concentrations, respectively. The major sources of PM2.5 are local and regional sources of thermal power plants, industrial parks, and waterborne transportation (domestic rivers and marine). The activities undertaken to remove Agent Orange (e.g., soil excavation, transportation, and rotary kiln incinerators) at the Bien Hoa airbase area also cause increases in the PM2.5 level in the atmosphere of Bien Hoa City. Graphical abstract

Evaluation of Mass Concentration and Size Distribution of Fine Particles (PM2.5) in Bien Hoa City, Dong Nai Province

Article

Apr 2022

Air pollution is one of the most concerning environmental issues, in which fine inhalable particles (PM2.5, with diameters that are generally 2.5 micrometers and smaller) concentration plays a key part. Bien Hoa city contains and locates close to several large industrial zones that might create sources of PM2.5 polluting the local air quality. This study monitors and evaluates PM2.5 concentration trends in Bien Hoa airport of Dong Nai province. PM samples are analyzed by Scanning Electron Microscopy (SEM) to recognize the surface pattern and size distributions are analyzed by ImageJ software. Ten samples of PM2.5 were obtained from sampling collected in October 2021. The results show that 24-h PM2.5 mass concentrations were from 15.2 µg/m3 - 50.4 µg/m3 with an average of 28.2 µg/m3; median of 24.1 µg/m3; and standard deviation of 12.2 µg/m3. The values are lower than the Vietnam National Technical Regulation on Ambient Air Quality (QCVN 05:2013/BTNMT) but far higher than the recommended values of the World Health Organization (WHO). SEM and image results indicate the distributions of the particles of 2.0 - 2.5 µm are minor, where the majority are particles with aerodynamic diameter ≤ 1.0 µm. Keywords: Air pollution; Fine particulate matters; PM2.5; Size distribution, Bien Hoa, Dong Nai.

Correlation Between Biomass Burning Tracers in Urban and Rural Particles in Silesia—Case Study

Article

Full-text available

Feb 2022
WATER AIR SOIL POLL

The major biomass burning tracers are thermal degradation products from the biopolymer cellulose, namely the didehydromonosaccharide derivatives levoglucosan, galactosan, and mannosan and the resin acid derivative dehydroabietic acid, with a minor contribution from β-sitosterol. Levoglucosan, galactosan, and mannosan were measured at two sites in Silesia, a rural (Rokitno) and industry region (Zabrze), during the winter of 2017/2018. The results showed that mean concentrations of the total tracers determined were 737 ng/m³ for Zabrze and 465 ng/m³ for Rokitno. Levoglucosan was the most abundant tracer; it was 83.2% of the determined tracers in Zabrze and 78.1% in Rokitno. The relative proportions of levoglucosan to mannosan have been used for source reconstruction of combustion-derived byproducts in atmospheric aerosols. The levoglucosan to mannosan ratio for Zabrze was 8.9 and for Rokitno 5.3; the levoglucosan to sum of mannosan and galactosan ratio was 6.2 and 3.8 for Zabrze and Rokitno, respectively. The correlation between tracers is high (0.73 to 0.97) and shows linearity. In order to compare the fuel type (by the coefficient of divergence (CD)) between different sites, the results from a previous work in health resort Krynica were used. The CD between Krynica and Rokitno as well as Krynica and Zabrze was equal to 0.633 and 0.712, respectively. The CD between Rokitno and Zabrze was equal to 0.175. Despite the biomass burning tracer measurements are mostly local, they have a huge impact on air pollution and climate changes.

An evaluation of the U.S. EPA's correction equation for PurpleAir sensor data in smoke, dust, and wintertime urban pollution events

Article

Full-text available

Mar 2023
AMT

PurpleAir sensors (PASs) are low-cost tools to measure fine particulate matter (PM) concentrations and are now widely used, especially in regions with few regulatory monitors. However, the raw PAS data have significant biases, so the sensors must be calibrated to generate accurate data. The U.S. EPA recently developed a national correction equation and has integrated corrected PAS data onto its AirNow website. This integration results in much better spatial coverage for PM2.5 (particulate matter with diameters less than 2.5 µm) across the US. The goal of our study is to evaluate the EPA correction equation for three different types of aerosols: typical urban wintertime aerosol, smoke from biomass burning, and mineral dust. We identified 50 individual pollution events, each having a peak hourly PM2.5 concentration of at least 47 µg m−3 and a minimum of 3 h over 40 µg m−3 and characterized the primary aerosol type as either typical urban, smoke, or long-range transported dust. For each event, we paired a PAS sampling outside air with a nearby regulatory PM2.5 monitor to evaluate the agreement. All 50 events show statistically significant correlations (R values between 0.71–1.00) between the hourly PAS and regulatory data but with varying slopes. We then corrected the PAS data using either the correction equation from Barkjohn et al. (2021) or a new equation that is now being used by the U.S. EPA for the AirNow Fire and Smoke Map (U.S. EPA, 2022b). Both equations do a good job at correcting the data for smoke and typical pollution events but with some differences. Using the Barkjohn et al. (2021) equation, we find mean slopes of 1.00 and 0.99 for urban and smoke aerosol events, respectively, for the corrected data versus the regulatory data. For heavy smoke events, we find a small change in the slope at very high PM2.5 concentrations (> 600 µg m−3), suggesting a ∼ 20 % underestimate in the corrected PAS data at these extremely high concentrations. Using the new EPA equation, we find slopes of 0.95 and 0.88 for urban and smoke events, respectively, indicating a slight underestimate in PM2.5 using this equation, especially for smoke events. For dust events, while the PAS and regulatory data still show significant correlations, the PAS data using either correction equation underestimate the true PM2.5 by a factor of 5–6. We also examined several years of co-located regulatory and PAS data from a site near Owens Lake, California (CA), which experiences high concentrations of PM2.5 due to both smoke and locally emitted dust. For this site, we find similar results as above; the corrected PAS data are accurate in smoke but are too low by a factor of 5–6 in dust. Using these data, we also find that the ratios of PAS-measured PM10 / PM1 mass and 0.3 µm / 5 µm particle counts are significantly different for dust compared to smoke. Using this difference, we propose a modified correction equation that improves the PAS data for some dust events, but further work is needed to improve this algorithm.

The Contents of Potentially Toxic Elements and Emission Characteristics of PM2.5 in Soil Fugitive Dust around Six Cities of the Yunnan-Guizhou Plateau in China

Article

Full-text available

Apr 2022

The contents of potentially toxic elements (V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb) and emission characteristics of PM2.5 in soil fugitive dust (SFD) in six Yunnan cities (Baoshan, Kunming, Wenshan, Honghe, Yuxi, and Zhaotong) were investigated in this research. The results showed that the contents of Zn and Pb in PM2.5 of SFD were the highest around Honghe and Yuxi, respectively, while the contents of Mn were the highest in PM2.5 of SFD around the other four cities. The enrichment factor and correlation indicated that the potentially toxic elements’ pollution degrees of PM2.5 of SFD around Kunming, Yuxi, and Honghe were higher than those around the other three cities and that potentially toxic elements were generally affected by metal smelting activities, and in Zhaotong, were affected by coal burning activities, while in Wenshan and Baoshan were less affected by human activities. The total emission of PM2.5 of SFD in the six cities was 7705.49 t in 2018. The total emission factor of PM2.5 of SFD reached the highest level from January to May and the lowest level from July to October. The health risk assessment showed that the potentially toxic elements in PM2.5 of SFD for children in the six cities and for adults in Baoshan, Kunming, Honghe, and Zhaotong had non-carcinogenic risk (non-carcinogenic risk thresholds were greater than 1), and As contributes most to non-carcinogenic risk. The carcinogenic risk value of Cr in PM2.5 of SFD in Kunming and Zhaotong was between 1 × 10−6 and 1 × 10−4, which had a certain carcinogenic risk. More attention should be paid to alleviate health risks posed by particle-bound potentially toxic elements through SFD.

Elemental composition of rural household dust in Brahmaputra fluvial plain: insights from SEM-EDS, receptor model, and risk assessment

Article

Full-text available

Aug 2022
ENVIRON GEOCHEM HLTH

The study attempts to look into the morphological characteristics, elemental composition, contamination, source contributions, and associated health risks in household dust of Napaam, a rural region in the Brahmaputra flood plain in North East India. Morphological evidence suggests that most of the house dust particles were sourced from vehicle abrasion and soil. Three contamination indices—enrichment factor (EF), index of geo-accumulation (Igeo), and pollution load index (PLI) indicated that Cl and four trace elements (Cu, Zn, As, and Pb) are significantly enriched in house dust with extreme pollution load. Principal component analysis (PCA) and positive matrix factorization (PMF) revealed 3 potential major sources of elements in house dust—traffic + re-suspension of road dust (35.8%), soil dust (22.2%), and river sediment deposit (16.4%). Two minor sources—biomass burning (13.3%), and construction activities (12.3%) were also identified. Based on health risk assessment (HRA), both children and adult were found to be susceptible to non-carcinogenic and carcinogenic risks. Graphical abstract

A coarse-to-fine weakly supervised learning method for green plastic cover segmentation using high-resolution remote sensing images

Article

Apr 2022
ISPRS J PHOTOGRAMM

Green plastic cover (GPC) is a kind of green plastic fine mesh primarily used for covering construction sites and mitigating large amounts of dust during construction. Accurate GPC detection is vital for monitoring urban environment and understanding urban development. Convolutional neural network (CNN)-based segmentation methods are widely used for detecting object extents, while they rely on high-quality pixel-level labels with high acquisition cost. In this regard, weakly supervised learning can achieve pixel-level segmentation using only image-level labels, by first generating the class activation map (CAM) to obtain initial pixel-level labels and then applying the CNN-based segmentation methods to detect object extents. However, these initial labels are usually incomplete and noisy, caused by the local high response property of CAM. Moreover, the CNN-based segmentation methods often lead to blurry object boundaries due to the gradual down-sampling of feature maps, and meanwhile suffer from the class imbalance problem in real scenarios. Given these problems, we introduce weakly supervised learning into GPC detection to lower the label acquisition cost. Furthermore, to improve the completeness and correctness of initial labels and mitigate the blurry boundary problem, we propose a coarse-to-fine weakly supervised segmentation method (called CFWS), consisting of three steps: 1) object-based label extraction; 2) noisy label correction; and 3) boundary-aware semantic segmentation. Moreover, to alleviate the class imbalance problem, we propose a classification-then-segmentation strategy and integrate it into the CFWS to detect GPC. We test the CFWS on two datasets from Google Earth and Gaofen-2 high-resolution images, respectively. The results show that the CFWS obtains more complete GPCs and effectively retains boundaries on both datasets compared to existing state-of-the-art methods. In real scenarios, the classification-then-segmentation strategy significantly reduces a large number of false alarms generated by direct segmentation. These findings confirm that the CFWS holds great potentials for large-scale GPC detection and urban environmental monitoring. The source code will be available at https://github.com/lauraset/Coarse-to-fine-weakly-supervised-GPC-segmentation.

Sensitivity analysis of the dust emission treatment in CMAQv5.2.1 and its application to long-range transport over East Asia

Article

Jul 2021
ATMOS ENVIRON

East Asian Dust (EAD) has had a measurable impact on global climate and air quality, including visibility and human health, in numerous locations around the globe over the past decade. The accuracy of an air quality modelling system to simulate dust events is vital for early warning systems. The most significant dust event observed in 6 years for northern Taiwan occurred during 4th – 9th April 2018, and was characterized by high wind speeds (9–13 m s-1) upon arrival to the region. We assessed the windblown dust emission treatment across various modifications and found better model performance by decreasing the soil moisture factor and updating the aerosol speciation profile over East Asia. In the optimized CMAQ simulation, uplifted dust particles reached a maximum height of 500–700 hPa, which is crucial for effective transport of the dust plume to the downwind Taiwan region. However, by tracking the vertical distribution profile, we found the model was insufficient to estimate dust aerosol after exiting from over the continent and entering the marine boundary layer. Our simulation indicated the dust event consisted of two plumes, where the first one was significantly impacted by wet deposition (-70.65%) from a rainfall belt stretching across Japan, Korea and the East China Sea. Then, low wind speed during a period of no precipitation over the marine area led to even greater dust deposition (-89.11%) from the second plume, resulting in a consistent negative bias for the simulation. This modeling study highlights the importance of improving the dust emission treatment for a better simulation of dust aerosol transport over the marine boundary layer. To reduce the uncertainty in the dust outflow region, the deposition mechanisms for the CMAQ dust treatment should be revised.

Airborne Particulate Matter Pollution in Akure Metro City, Southwestern Nigeria, West Africa: Attribution and Meteorological Influence

Article

Full-text available

Jun 2021

We investigated the origin, seasonal air quality indices (AQI), and the likely fate of particulate matters (PM10 and PM2.5) across Akure, a metro capital city in the Niger Delta region of Nigeria. The analysis included the contributions of meteorological properties to the distribution of the particulates, especially fugitive dust. We observed that the PM concentrations exhibited significant differences in the differential, spatial, and temporal patterns. During the wet season, the air movement zones were turbulence, interception, and divergence, whereas only the interception zone was observed in the dry season. For the wet season, the average daily PM2.5 and PM10 concentrations (in ppm) varied from 7 to 62 and 11 to 85, respectively, while, the respective daily mean concentrations ranged from 11 to 63 and 17 to 86. Furthermore, the fine/coarse ratio (PM2.5/PM10) ranged 0.63–0.83 and 0.65–0.73 during the wet and dry seasons, respectively, with 90% of the ratio being ≈0.70. The statistical t-value for PM10, PM2.5, and AQI were 0.60, 0.61, and 0.45, respectively, while their corresponding P-values were 0.56, 0.55, and 0.66, indicating no significant seasonal variations. Overall, Akure’s air quality is majorly influenced by environmental conditions (based on anthropogenic activities) and merely by meteorological conditions. Conclusively, to achieve sustainable development, enforced environmental management that involves green and blue economies as the panacea to atmospheric pollution in Akure should be implemented.

Bottom-Up Emission Inventory and Its Spatio-Temporal Distribution from Paved Road Dust Based on Field Investigation: A Case Study of Harbin, Northeast China

Article

Full-text available

Mar 2021

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 270207 t, 54597 t, 14059 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.

Chemical source profiles of fine particles for five different sources in Delhi

Article

Full-text available

Feb 2021

Increasing emissions from sources such as construction and burning of biomass from crop residues, roadside and municipal solid waste have led to a rapid increase in the atmospheric concentrations of fine particulate matter (≤2.5µm; PM2.5) over many Indian cities. Analyses of their chemical profiles are important for receptor models to accurately estimate the contributions from different sources. We have developed chemical source profiles for five important pollutant sources - construction (CON), paved road dust (PRD), roadside biomass burning (RBB), solid waste burning (SWB), and crop residue burning (CPB) - during three intensive campaigns (winter, summer and post-monsoon) in and around Delhi. We obtained chemical characterisations of source profiles incorporating carbonaceous material such as organic carbon (OC) and elemental carbon (EC), water-soluble ions (F-, Cl-, NO2-, NO3-, SO42-, PO43-, Na+ and NH4+), and elements (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Rb, Sr, Ba, and Pb). CON was dominated by the most abundant elements, K, Si, Fe, Al, and Ca. PRD was also dominated by crustal elements, accounting for 91% of the total analysed elements. RBB, SWB and CPB profiles were dominated by organic matter, which accounted for 94%, 86.2% and 86% of the total PM2.5, respectively. The database of PM emission profiles developed from the sources investigated can be used to assist source apportionment studies for accurate quantification of the causes of air pollution and hence assist governmental bodies in formulating relevant countermeasures.

Removal of Hydrogen Sulfide from Biogas Using a Bubbling Tank Fed with Aerated Wastewater

Article

Mar 2020

The work develops a simple bubbling tank scrubber that is fed with aerating wastewater for the removal of hydrogen sulfide (H2S) in biogas. A 2,000 L plastic tank, in which fixed liquid levels 0.80 and 1.0 m and volumes of 1.1 and 1.4 m³ was kept, was used for the scrubbing tests. A polyvinyl chloride (PVC) pipe with holes of 1 mm diameter was used to sparge the biogas into the tank liquid. Results indicate that with an influent liquid of pH 7.5–7.7, a flow rate of 23–25 L min–1, influent biogas flow rates of 0.050–0.200 m³ min–1, and a H2S concentration of 907 ± 212 ppm, the pH of the effluent liquid stabilized at 6.6–6.9. With gas/liquid rate ratio of 2–8 m³ m–3 liquid and volumetric gassing intensities of 0.04–0.20 m³ m–3 liquid min–1, average H2S removals of 86–71% were obtained. Absorption of CO2 in the tested digester gas into the scrubbing liquid caused a decrease in the pH, thus decreasing the H2S removal efficiency. Increasing pH of the scrubbing liquid to 8.0 improved the H2S removal efficiency to as high as 99%.

A Dynamic Dust Emission Allocation Method and Holiday Profiles Applied to Emission Processing for Improving Air Quality Model Performance

Article

Jan 2019

An accurate depiction of temporal and spatial variations in emissions is critical in simulating air quality with atmospheric chemical transport models. Most emission processing systems typically use prescribed profiles to allocate anthropogenic emissions based on the assumptions that the temporal variance is periodical and spatial variance is time-independent. However, these assumptions are not applicable to emission sources heavily influenced by meteorology and holiday activity. In this study, we improved the temporal and spatial allocation of anthropogenic emissions by, first of all, developing a dynamic allocation method for fugitive dust that uses the negative correlation between dust emissions and precipitation, based on hourly rainfall data generated by the Weather Research and Forecasting model. Second, we employed holiday-specific profiles that were established using continuous emission monitoring system and traffic flow monitoring data to allocate power plant and on-road mobile emissions during the Spring Festival period, when human activity differs considerably from that of non-holiday periods. The new dynamic allocation method and holiday-specific profiles were applied to emissions in the Pearl River Delta region as a demonstration. Validated using a chemical transport model, this method obviously improved the model performance for periods with rainfall, with the normalized mean bias (NMB) decreasing by 6.27% for PM10 (particulate matter with a diameter of ≤ 10 µm) and 4.33% for PM2.5 (particulate matter with a diameter of ≤ 2.5 µm). The holiday simulations revealed that the holiday-specific profiles mitigated overestimations of NO2, SO2, and PM10 for the Spring Festival period, with the NMBs decreasing by 37.95%, 18.56%, and 20.83%, respectively. Hence, refining the allocation of emissions improved model simulation and air quality forecasting.

Air quality and PM 10 -associated poly-aromatic hydrocarbons around the railway traffic area: statistical and air mass trajectory approaches

Article

May 2019
ENVIRON GEOCHEM HLTH

Diesel engine railway traffic causes atmosphere pollution due to the exhaust emission which may be harmful to the passengers as well as workers. In this study, the air quality and PM 10 concentrations were evaluated around a railway station in Northeast India where trains are operated with diesel engines. The gaseous pollutant (e.g. SO 2 , NO 2 , and NH 3) was collected and measured by using ultraviolet-visible spectroscopy. The advanced level characterizations of the PM10 samples were carried out by using ion chromatography, Fourier-transform infrared, X-ray diffraction, inductively coupled plasma optical emission spectrometry , X-ray photoelectron spectroscopy, field-emission scanning electron microscopy with energy-dispersive spectroscopy, and high-resolution transmission electron microscopy with energy-disper-sive spectroscopy techniques to know their possible environmental contaminants. High-performance liquid chromatography technique was used to determine the concentration of polycyclic aromatic hydrocarbons to estimate the possible atmospheric pollution level caused by the rail traffic in the enclosure. The average PM 10 concentration was found to be 262.11 lg m-3 (maximum 24 hour) which indicates poor air quality (AQI category) around the rail traffic. The statistical and air mass trajectory analysis was also done to know their mutual correlation and source apportionment. This study will modify traditional studies where only models are used to simulate the origins.

Air quality and PM10-associated poly-aromatic hydrocarbons around the railway traffic area: statistical and air mass trajectory approaches

Article

Full-text available

Oct 2019
ENVIRON GEOCHEM HLTH

Diesel engine railway traffic causes atmosphere pollution due to the exhaust emission which may be harmful to the passengers as well as workers. In this study, the air quality and PM10 concentrations were evaluated around a railway station in Northeast India where trains are operated with diesel engines. The gaseous pollutant (e.g. SO2, NO2, and NH3) was collected and measured by using ultraviolet–visible spectroscopy. The advanced level characterizations of the PM10 samples were carried out by using ion chromatography, Fourier-transform infrared, X-ray diffraction, inductively coupled plasma optical emission spectrometry , X-ray photoelectron spectroscopy, field-emission scanning electron microscopy with energy-dispersive spectroscopy, and high-resolution transmission electron microscopy with energy-dispersive spectroscopy techniques to know their possible environmental contaminants. High-performance liquid chromatography technique was used to determine the concentration of polycyclic aromatic hydrocarbons to estimate the possible atmospheric pollution level caused by the rail traffic in the enclosure. The average PM10 concentration was found to be 262.11 µg m⁻³ (maximum 24 hour) which indicates poor air quality (AQI category) around the rail traffic. The statistical and air mass trajectory analysis was also done to know their mutual correlation and source apportionment. This study will modify traditional studies where only models are used to simulate the origins.

Characterization of individual particles and meteorological conditions during the cold season in Zhengzhou using a single particle aerosol mass spectrometer

Article

Dec 2018
ATMOS RES

To investigate the formation of haze during the cold season, continuous ambient air measurements were taken at an urban site in Zhengzhou from October 10, 2016 through December 31, 2016 using a single particle aerosol mass spectrometer. In total, 4,099,800 particles were analyzed and classified into eight major particle types: elemental carbon (EC, 36.7%), organic carbon (OC, 30.0%), ECOC (8.6%), K-rich (13.0%), levoglucosan (1.2%), metal (2.2%), NH4-K (2.1%), and dust (6.2%). By combining these measurements with correlation analysis and wind data, particle sources were determined to be vehicles, industrial emissions, coal combustion, biomass burning, secondary aerosols, agriculture, and dust. Additionally, analysis of mixing states indicated that particles underwent substantial aging and secondary OC particles were dominant OC species. Temporal profiles of meteorological parameters, mixing states, and particle types during a typical haze episode revealed that EC and OC particles were dominant components during haze formation, and a northeastern transport route (Anyang-Zhengzhou and Puyang-Xuchang) for OC particles was identified by potential source contribution function and concentration weighted trajectory analysis. Relatively higher humidity and lower temperature favored the formation of secondary inorganic aerosol. Wind direction and speed determined the transport, formation, and elimination of stagnant weather conditions. In sum, heavy haze during the cold season in Zhengzhou was observed due to extensive aerosol aging under adverse weather conditions (i.e., northeastern wind direction, wind speed <2 m s⁻¹, temperature < 10 °C, relative humidity >60%, temperature inversion, and uniform pressure field).

Pollution characteristics, human health risk through multiple exposure pathways, and source apportionment of heavy metals in PM 10 at Indo-Gangetic site

Article

Full-text available

Dec 2018

This study assesses the heavy metal (Pb, Zn, Ni, Fe, Mn, Cr, Cd, As, Co and Cu) concentrations in PM10 in Agra, India. The analysis of heavy metals was carried out by Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) after digestion of quartz fiber filter paper. The annual mean concentration for PM10 was 214.61 μg m⁻³ and higher than WHO and NAAQS limit. The results showed mean value of heavy metals followed the order: Fe > Zn > Cr > Mn > Pb > Ni > Cu > Co > As>Cd. The carcinogenic risks of As, Cd, Co, Cr, Pb and Ni for both children and adults via dermal contact and ingestion exposure were within the acceptable level (<1 × 10⁻⁴). Co showed potential carcinogenic risk only for adults and Cr for both children and adults via inhalation. The HQ values for Cr, Mn, Fe, Ni, Cu, Zn, As, Pb and Cd via ingestion and dermal contact exposure for both children and adults were all lower than the safe level. The HQ values for Mn, Co, Ni and As to both children and adults via inhalation and for Co to only children via ingestion exposure were higher than the safe level. The source identification was confirmed through enrichment factor (EF), cluster analysis (CA) and principal component analysis (PCA).

The Effects of Outdoor Source on Pollution Characteristics and Dynamic Changes of Particulate Matter in an Office

Article

Full-text available

Nov 2018

The indoor air quality has a direct impact on human health. Particulate matter is one of the important factors affecting the indoor air quality. The paper selects an office as the study object and studies the pollution characteristics and dynamic changes of indoor particulate matter in different outdoor pollution levels. The mass concentration of outdoor PM10 is used as the evaluation basis of the outdoor pollution level. The outdoor PM10 concentration levels are divided into the range of 200–300, 300–400, 400–500, 500–600, 600–700 μ g·m ⁻³ , individually. Firstly, the change characteristics of the mass concentration and the number concentration of the particulate matter in the five outdoor conditions are analyzed. Secondly, the maximum increase values and the maximum increase rates of the mass concentrations of different particle sizes in the five conditions are compared. Then, the penetration factors of the particulates in different sizes are compared among the five conditions. Finally, the correlation between indoor particulate matter and outdoor particulate matter is studied. The study results show that the effect of outdoor infiltration has a great influence on the indoor PM1 mass concentration, and the penetrating factors of the particulate matter between 0.3 μ m and 0.5 μ m are higher than 0.6; their permeability is the most obvious.

Chemical source profiles of urban fugitive dust PM2.5 samples from 21 cities across China

Article

Aug 2018
SCI TOTAL ENVIRON

Urban fugitive (road and construction) dust PM2.5 samples were collected in 21 cities of seven regions in China. Seven water-soluble ions, eight sub-fractions of carbonaceous components, and 19 elements were determined to investigate the chemical profiles of urban fugitive dust. Among the analyzed chemical compositions and on regional average, the elemental compositions showed the highest proportion (12.5-28.9% in road dust (RD) and 13.1-38.0% in construction dust (CD)), followed by water-soluble ions (5.1-19.0% in RD and 4.2-16.4% in CD) and carbonaceous fractions (5.4-9.6% in RD and 4.9-9.3% in CD). Chemical compositions measured in CD were all slightly lower than those in RD although statistically insignificant (p > 0.05). Soil dust, which was estimated from Fe concentration, was proved to be the biggest contributor to urban fugitive dust PM2.5 mass. While, it showed a higher contribution in Northern China (71.5%) than in Southern China (52.1%). Higher enrichment factors were found for elemental S, Zn and Pb in RD than CD, reflecting stronger anthropogenic sources (i.e. vehicle exhaust) in RD. Low NO3-/SO42- and high SO42-/K+ ratios both indicated that fugitive dust was strongly influenced by stationary sources (e.g. coal combustion), and this influence was especially strong in Northern China. Coefficients of divergence proved that dust profiles within the same region were more similar than across regions, reflecting that urban fugitive dust was influenced more by local sources than long-range transport.

Particulate Matter Monitoring: Past, Present and Future

Article

Full-text available

Dec 2017

The health problems caused by exposure to airborne Particulate Matter (PM) beyond safe limits have been studied for many years. Government regulatory agencies have adapted and updated the safe exposure limits as more progress is made both in policy developments and detection system design. Bulky PM detectors, though very accurate do not provide sufficient spatial and temporal resolution, and are static and expensive. Current much smaller commercial PM sensors are mobile but still mostly too expensive and largely still too big for real-time continuous personal use. They also must be calibrated to convert their counts to mass concentration despite their variation from unit to unit. The continuous drive towards having a cheaper, smaller, yet more effective PM sensors for personal exposure analysis and indoor environments is pushing the current boundaries of current techniques. Emerging PM sensing techniques must now achieve this, while also linking to other structured source apportionment and semantic analysis of air quality data aimed at providing useful information about user activities mostly provided via the internet. This review highlights research on PM detection and monitoring, covering methods and principle of operation of detection instruments, emerging trends and future outlooks. Further, this work reviews PM detection challenges, measurement interpretation and possible solutions going forward. Citation: Occhipinti LG, Oluwasanya PW (2017) Particulate Matter Monitoring: Past, Present and Future. Int J Earth Environ Sci 2: 144. doi: https://doi.

PM10 and PM2.5 chemical source profiles of road dust over China: Composition, spatio-temporal distribution, and source apportionment

Article

Sep 2023

Relationship between air pollutant distribution and large-scale circulation

Article

Full-text available

Jun 2023

The Antarctic Oscillation (AAO) has long been linked to the weather and climate of the Northern Hemisphere (NH); however, its linkage with pollutant distribution in China has seldom been discussed. In this study, using the boundary layer structure index (BLSI), NOAA–ESRL and NCEP/NCAR reanalysis data, the effect of boreal summer AAO on pollutant distribution was studied. Regarding the relationship between AAO and pollutant distribution, the Antarctic Oscillation Index (AAOI) was correlated with the dust surface mass concentration (DSMC) of PM2.5 over China, in which boreal summer (June and July) AAO signals (JJ–AAOI) were selected as the determinant leading factor in establishing a relationship with pollutants during boreal winter (from November to February). The results show that the average of JJ–AAOI has a significant correlation with the DSMC of PM2.5. August–October were the most significant months over the Antarctic, as indicated by their large coverage of significant areas compared to the coverage of other months. These findings imply that the signals of JJ–AAOI can be stored in Antarctic sea ice up to August–October before they affect the atmospheric boundary layer (ABL), which ultimately affects pollutant distribution in the end. The analysis of the relationship between the DSMC of PM2.5 and large-scale circulation first involved the use of the empirical orthogonal function (EOF) of the decomposed winter DSMC of PM2.5. The time series from the EOF1 analysis showed a wave train of four years of positive and negative (+, −, +), followed by a decadal negative value. Moreover, the analysis of the composite difference of meridional circulation between the years of high and low JJ–AAOI shows significant ascending and southerly anomalies at around 25 °N and 35 °N during the higher JJ–AAOI years. These results act as a good starting point for the effort to develop a comprehensive forecasting model for pollutant distribution.

Humic-Based Polyelectrolyte Complexes for Dust Suppression

Article

Full-text available

Mar 2023

Alexander Volikov

The present study proposes a novel application of humic substance–aminosilsesquioxane polyelectrolyte complexes (HS–ASQ) as dust suppressants. These complexes are synthesized through the reaction between humic substances (HS) and 3-aminopropyltriethoxysilane (APTES) in aqueous solution, resulting in the formation of active silanol groups that can bind to mineral surfaces and condense, forming gels. The HS–ASQ compositions were found to have a high sorption capacity for dust particles and could form coatings on their surface without cementing the dust, making them potentially useful for environmental applications. The viscosity of the HS–ASQ compositions can be controlled by adding carboxymethylcellulose (CMC), which also enhances their dust suppression abilities. Different compositions of HS–ASQ were synthesized by varying the proportions of APTES and CMC, and dust treated with these samples was assessed for its resistance to wind erosion using a laboratory-scale setup. Treatment with the HS–ASQ composition resulted in substantial reductions in PM10 and PM2.5 concentrations (particulate matter with aerodynamic diameters of 10 µm and 2.5 µm, respectively) of up to 77% and 85%, respectively, compared to the control.

A recent high-resolution PM2.5 and VOCs speciated emission inventory from anthropogenic sources: A case study of central China

Article

Dec 2022
J CLEAN PROD

An evaluation of the U.S. EPA’s correction equation for Purple Air Sensor data in smoke, dust and wintertime urban pollution events

Preprint

Full-text available

Oct 2022

PurpleAir Sensors (PASs) are low-cost tools to measure fine particulate matter (PM) concentrations and are now widely used, especially in regions with few regulatory monitors. However, the raw PAS data have significant biases, so the sensors must be calibrated to generate accurate data. The U.S. EPA recently developed a national correction equation and have integrated corrected PAS data onto its AirNow website. This integration results in much better spatial coverage for PM2.5 across the U.S. The goal of our study is to evaluate the EPA correction equation for three different types of aerosols: typical urban wintertime aerosol, smoke from biomass burning, and mineral dust. We identified 50 individual pollution events, each having a peak hourly PM2.5 concentration of at least 47 µg m-3 and a minimum of 3 hours over 40 µg m-3 and characterize the primary aerosol type as either typical urban, smoke or dust. For each event, we paired an PAS sampling outside air with a nearby regulatory PM2.5 monitor to evaluate the agreement. All 50 events show statistically significant correlations (R values between 0.71–1.00) between the hourly PAS and regulatory data, but with varying slopes. Using the standard EPA correction for the typical urban and smoke aerosols, we find average slopes of 1.00 and 0.99, respectively. This means that the standard EPA correction is highly effective at generating accurate data for these aerosol types. For heavy smoke events, we find a small change in the slope at very high PM2.5 concentrations (>600 µg m-3), suggesting a ~20 % under-estimate in the corrected PAS data at these extremely high concentrations. For dust events, while the PAS and regulatory data still show significant correlations, the PAS data using the standard correction underestimates the true PM2.5 by a factor of 5–6. We also examined several years of co-located regulatory and PAS data from a site near Owens Lake, CA, which experiences high concentrations of PM2.5 due to both smoke and dust. For this site we find similar results as above; the PAS corrected data are accurate in smoke, but are too low by a factor of 5–6 in dust. Using these data we also find that the ratios of PAS measured PM10 to PM1 mass and 0.3 µm to 5 µm particle counts are significantly different for dust compared to smoke. Given the ability of the PAS data to identify dust aerosols, we propose a modified correction algorithm that significantly improves the PAS data for dust events.

Evaluation of Health Hazard and Governance Performance of Air Pollution: A Case Study of Z City

Article

Full-text available

Apr 2022

Based on the date of the main pollutant discharge and the change of pollutant concentration in Z city, this study performed the statistical analysis of the concentration data in excel. The data covers 3 years from 1 January 2015 to 31 December 2017. An exposure-response relationship model was used established to evaluate the health hazards caused by air pollution and the corresponding economic losses, further analyzing the relationship between air pollution, health hazards, and economic benefits. The results of the study showed that the changes in SO2 and NO2 concentrations in Z City from 2015 to 2017 have a great influence on the mortality rate of the local population, respiratory mortality, the rate of internal medicine of outpatients, and the rate of chronic bronchitis disease. The economic losses between 2015 and 2017 caused by PM10, the primary pollutant in the air, were 3.9 billion, 3.5 billion, and 2.9 billion respectively, accounting for 3.60%, 2.88%, and 2.09% of Z City's GDP, which were enormous. Finally, countermeasures of feasible treatment and in government performance were put forward.

Oxidative stress–inducing effects of various urban PM2.5 road dust on human lung epithelial cells among 10 Chinese megacities

Article

Nov 2021
ECOTOX ENVIRON SAFE

PM2.5 Road dust samples were collected from 10 representative cities in southern and northern China for examination of chemical components and oxidative stress levels in A549 cells. Downtown road dust was abundance of heavy metals, EC and PAHs compared to nondowntown road dust. Source apportionment also revealed the relative higher contribution of vehicle emission to downtown (35.8%) than nondowntown road dust (25.5%). Consequently, downtown road dust induced much higher intracellular reactive oxidative species (ROS) levels than that from nondowntown (p < 0.05). This study highlights that the ROS-inducing capacity of road dust in China is lower at lower latitudes, which resulted in a significantly higher ROS-inducing capacity of road dust from northern cities than southern ones. Hotspot analysis demonstrated that heavy metals (i.e., Cr, Zn, Cu and Pb) in road dust were the most closely associated with ROS production in A549 cells. Vehicle emission and combustion emission in road dust were identified to be correlated with cellular ROS production. The findings highlight the ROS-inducing effect of PM2.5 road dust and also serve as a reference to make the targeted solutions for urban road dust pollution control, especially from a public health perspective.

Detailed Physicochemical Characterization of the Ambient Fine and Ultrafine Particulate Mixture at a Construction Site

Article

Jul 2021

This paper presents a detailed characterization of the size and shape distributions, and chemical compositions of ambient fine and ultrafine particles collected at the site of a building demolition and construction project at the Pennsylvania State University. Particle samples were collected with a nine-stage cascade impactor, characterized via transmission electron microscopy and energy dispersive spectroscopy for elemental compositions, and images analyzed for morphological features. 89.3% of the particles collected by count were ultrafine particles or aggregates of ultrafine particles that disaggregated during the collection process. The mean particulate matter mass and count concentrations were 167.2 µg/m3 and 16,232 particles/cm3, respectively. 72.2% of the particles by count were morphologically circular on two-dimensional images and 74.0% of the particles by count had an aspect ratio of between 1:1 and 2:1. The five most prevalent elements found in the samples were carbon, oxygen, silicon, sulfur, and calcium, with corresponding mass fractions of 40.8%, 26.4%, 7.6%, 5.1%, and 4.7%. Based on the current regulatory occupational exposure limits, the particulate matter at the construction site was within permissible concentrations. These results enable a comparison of a real-world particulate exposure environment to hazard levels determined through single-particle-type exposure studies.

Mechanism of Pb Absorption in Wheat Grains

Article

Mar 2021
J HAZARD MATER

Atmospheric deposition is the primary source of external environmental media for lead (Pb) influx in wheat grains. However, the mechanisms of Pb grain absorption remains unclear. We explored this mechanism through comparative experiments, involving defoliating leaf blades (TG) and a control group (CK) of field wheat after the anthesis stage. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy analysis displayed that leaves and ears can directly absorb atmospheric deposition Pb through stomata. Compared with CK, the yield, grain Pb content, and grain Pb accumulation of TG wheat were significantly decreased by 13.25%, 22.10%, and 32.58%, respectively. Combined with the Pb isotope analysis, the ear had the highest contribution to grain Pb followed by leaf and root. Simultaneously, the absorption rate of grain Pb demonstrated a dynamic trend of "N" shape. Dominant contribution periods of the root, leaf, and ear organs to grain Pb accumulation were different. Unlike the root system, the contribution of the aboveground to grain Pb increased gradually, and the contribution of leaf and ear to grain Pb were mainly concentrated in the early and late filling stage, respectively. Our findings can provide a theoretical basis for the control of Pb pollution in grains.

Evaluation of characterization and filtration performance of air cleaner materials

Article

Oct 2020

The following common filter materials were characterized and evaluated for filtration performance: glass fiber (GF), polytetrafluoroethylene (PTFE), and polypropylene (PP). The pressure drop of GF and PFFE was found to be approximately 500–600 Pa at 0.10 m/s face velocity, and the pressure drop for the PP is lower at only 30–80 Pa. The filtration efficiency of PTFE and GF was determined as 99.067% and 98.234%. Results show the filtration efficiency of PP is between 95.836–98.732%, but the filtration efficiency of PP filter materials will decrease 20–60% after electrostatic removal. The contribution of various particle collection mechanisms to the overall efficiency of the filter was calculated using the single-fiber filtration efficiency model. The diffusion of the aerosol particles at submicron size was the main collection mechanism, and the contribution of the gravity sedimentation mechanism to the measured particle size range was very low or even negligible.

Distribution characteristics and policy-related improvements of PM2.5 and its components in six Chinese cities

Article

Aug 2020
ENVIRON POLLUT

This study presents the distribution characteristics and possible sources of fine particulate matter (PM2.5) and its components, as well as policy-related pollution reduction in the Chinese cities of Jinan, Shijiazhuang (SJZ), Chengdu, Wuxi, Wuhan, and Harbin (HRB). PM2.5 samples were collected using mid-volume samplers during the autumn of 2017 in all six cities. The samples were analyzed to determine the ambient PM2.5 compositions, including the concentrations of water-soluble inorganic ions (WSIIs), carbonaceous aerosols, and elements concentrations. The chemical ratios of organic carbon to elemental carbon and nitrate to sulfate as well as the enrichment factors of elements were calculated to establish the possible sources of PM2.5 in all six cities. The highest PM2.5 concentration was 152 μg/m³ in SJZ, while the lowest concentration was 47 μg/m³ in HRB. During the sampling period in these six cities, the PM2.5 concentrations exceeded the World Health Organization recommended daily average air quality guidelines by 2.4 to 6.1 times, and WSIIs, carbonaceous aerosols, and elements accounted for 31.8%–61.6%, 9.8%–35.1%, and 0.9%–2.5% of the PM2.5, respectively. In 2013, the Chinese government formulated the Air Pollution Prevention and Control Action Plan (APPCAP) for controlling air pollution, and effective measures have been implemented since then. Compared with previous studies conducted during 2009–2013 before the implementation of the APPCAP, the concentrations of PM2.5 and most of its components decreased to varying degrees, and large changes in the chemical ratios of PM2.5 components were observed. These results indicate that PM2.5 sources vary among these six cities and that China has improved the ambient air quality in these cities through the implementation of air pollution control policies. The APPCAP have achieved considerable results in continuously reducing pollution concentrations, although the air pollution concentrations observed in this study remain high compared with those of other countries.

Characteristics and the Potential Influence of Fugitive PM10 Emissions from Enclosed Storage Yards in Iron and Steel Plant

Article

Full-text available

Aug 2020

Fugitive particle emission of enclosed storage yards in iron and steel plant is a complicated and multivariable problem, which will have negative impacts on the environment and economy. Researchers have discussed methodologies of emission estimation in open storage yards, but rarely focused on enclosed ones. However, enclosed storage yards are commonly adopted in most industries in China. This paper links onsite observation and computational fluid dynamics (CFD) to estimate the impact of fugitive PM10 emissions from enclosed storage yards on the open air. By collecting and analyzing PM10 samples at three sites inside the yard and one site outside, The result shows that PM10 concentration is in the range of 7.3 ± 1.5~13.4 ± 4.2 mg/m3, which is extremely high in an enclosed storage yard, and significantly influences workers’ health inside and outside atmospheric aerosols. The CFD model simulation is conducted by considering particle deposition, particle emission sources of shovel loader and road dust emission, as well as different wind direction and wind speed. The result shows that PM10 discharge rate from the enclosed area to open-air is significantly influenced by wind velocity and direction, e.g., the result of northwest wind with wind speed in 12.7 m/s is eight times higher than wind speed in 2.5 m/s with the same wind direction, and are 47 and 62 times higher than the east and west wind direction with the same wind speed in 12.7 m/s, respectively. In this case, the PM10 discharge rate is about 131.7 ton/year, which contains about 38~55 ton/year iron-relating particles. This will directly contribute PM10 to open-air and may produce secondary aerosols, due to heterogeneous catalytic reaction. This work identifies the important contribution of fugitive emissions and provides an approach for fugitive emission estimation of industries to the surrounding air. The results provide a reference for material yard zoning and fugitive emission control from minimizing influence from the meteorological condition and reducing source discharge inside.

Characteristics, sources, and reactions of nitrous acid during winter at an urban site in the Central Plains Economic Region in China

Article

Full-text available

Jun 2020
ATMOS CHEM PHYS

Nitrous acid (HONO) in the core city of the Central Plains Economic Region in China was measured using an ambient ion monitor from 9 to 31 January 2019. Measurement time intervals were classified into the following periods in accordance with the daily mean values of PM2.5: clean days (CDs), polluted days (PDs), and severely polluted days (SPDs). The HONO concentrations during CD, PD, and SPD periods were 1.2, 2.3, and 3.7 ppbv, respectively. The contributions of the homogeneous reaction, heterogeneous conversion, and direct emissions to HONO sources varied under different pollution levels. The mean values of the net HONO production of the homogeneous reaction (POH+NOnet) in CD, PD, and SPD periods were 0.13, 0.26, and 0.56 ppbv h−1, respectively. The average conversions of NO2 (CHONO) in CD, PD, and SPD periods were 0.72×10-2, 0.64×10-2, and 1.54×10-2 h−1, respectively, indicating that the heterogeneous conversion of NO2 was less important than the homogeneous reaction. Furthermore, the net production of the homogeneous reaction may have been the main factor in the increase of HONO under high-NOx conditions (i.e., when the concentration of NO was higher than that of NO2) at nighttime. Daytime HONO budget analysis showed that the mean values of the unknown source (Punknown) during CD, PD, and SPD periods were 0.26, 0.40, and 1.83 ppbv h−1, respectively. The values of POH+NOnet, CHONO, and Punknown in the SPDs period were comparatively larger than those in other periods, indicating that HONO participated in many reactions. The proportions of nighttime HONO sources also changed during the entire sampling period. Direct emissions and a heterogeneous reaction controlled HONO production in the first half of the night and provided a contribution that is larger than that of the homogeneous reaction. The proportion of homogenization gradually increased in the second half of the night due to the steady increase in NO concentrations. The hourly level of HONO abatement pathways, except for OH + HONO, was at least 0.22 ppbv h−1 in the SPDs period. The cumulative frequency distribution of the HONOemission∕HONO ratio (less than 20 %) was approximately 77 %, which suggested that direct emission was not important. The heterogeneous HONO production increased when the relative humidity (RH) increased, but it decreased when RH increased further. The average HONO∕NOx ratio (4.9 %) was more than twice the assumed globally averaged value (2.0 %).

Establishment and evaluation of anthropogenic black and organic carbon emissions over Central Plain, China

Article

Apr 2020
ATMOS ENVIRON

The Central China represented by Henan Province is one of the most haze-polluted regions in China with high levels of black carbon (BC) and organic carbon (OC) emissions. In this study, a 2016-based BC and OC emission inventory of Henan Province was developed based on detailed activity data and latest emission factors from different sources involving particulate matter. The total annual emissions of BC and OC were estimated to be 117.6 kt and 162.8 kt, respectively. Industrial process (44.2%) and industrial combustion (17.0%) were the top two contributors for BC emission, whereas OC emission was mainly from biomass burning (36.8%). Typical industrial cities were the major contributors to BC emission, by contrast, relatively higher OC emission was concentrated on agricultural cities in the southeast of Henan Province. The OC/BC ratios of industrial cities were generally lower than those of southeastern agricultural cities. The monthly variations presented that the highest BC and OC emissions were concentrated in January and June, respectively. Overall, in this study, the quantitative uncertainty ranges on the 95% confidence interval were approximately −30%–47% for BC and −38%–65% for OC. The emission inventory was also verified by qualitative comparison with other studies and indirect evaluation of OCpri/EC ratios, and the result was within a reasonable range. The ways of discussion and evaluation in this study can provide reference for other regions.

Characteristics and formation mechanisms of secondary inorganic ions in PM2.5 during winter in a central city of China: Based on a high time resolution data

Article

Oct 2019
ATMOS RES

This study aimed to investigate the characteristics of the water-soluble ions concentrations in atmospheric particulates. Highly time-resolved measurements of inorganic ions associated with PM2.5 were conducted from December 1, 2017 to February 28, 2018 in Zhengzhou. The hourly mean and standard deviation of PM2.5 concentration during the observation episodes were 108.2 ± 80.7 μg/m³. The hourly mass concentration of PM2.5 increased from 8 μg/m³ to 438 μg/m³ throughout the entire observation. The proportion of water-soluble inorganic ions in PM2.5 was 52.5% throughout the entire observation period. The ions existed mainly in the form of (NH4)2SO4 and NH4NO3. The average mass concentration ratio of NO3⁻ to SO4²⁻ was 1.9 ± 0.8 throughout the entire observation period, which initially increased and then decreased with the increased pollution level. The average ratio of the molar equivalent concentration of [NH4⁺] to that of [NO3⁻ + SO4²⁻] was 1.14 ± 0.27, which decreased with the increased pollution level. Homogeneous reactions played an important role in the formation of nitrate, while, the heterogeneous reactions were important in the formation of sulfate. Both of the values of sulfur oxidation ratios (SOR) and nitrogen oxidation ratios increased with relative high humidity (RH) condition; especially, the SOR values sharply increased when the RH was above 50%. The results of potential source contribution function model demonstrated that the western and northeastern regions of Zhengzhou had a greater influence on PM2.5 pollution in Zhengzhou. All these results suggested that reducing the emission of precursors of secondary inorganic ions was highly important in controlling PM2.5 pollution in Zhengzhou.

Direct evidence of lead contamination in wheat tissues from atmospheric deposition based on atmospheric deposition exposure contrast tests

Article

Sep 2019
ECOTOX ENVIRON SAFE

A field experiment was conducted to assess the atmospheric deposition effects on lead (Pb) contamination in wheat by two contrasting treatments: wheat exposed or not to atmospheric deposition. Plants were housed in a shed during wheat greening for the non-exposed treatment. The Pb contents of wheat during different growth stages, of soil and of atmospheric deposits were analysed and combined with Pb stable isotope data to quantify the contribution of atmospheric deposition and soil to Pb in wheat tissue. The Pb content in atmospheric deposits was significantly higher than those in soil and wheat tissue, and the Pb content in wheat tissue exposed to atmospheric deposition was significantly higher than the Pb content in non-exposed tissue (p < 0.05). The 206Pb/207Pb of soil was significantly higher than the 206Pb/207Pb of atmospheric deposits (p < 0.05), and soil and atmospheric deposition were the two sources of Pb in wheat tissue. Atmospheric deposition was the main source of wheat tissue Pb in the exposed treatment, and most of the wheat tissue Pb, except for that in the stem, also came from atmospheric deposition in the maturing stage. The proportion of Pb from atmospheric deposition in roots, stems and leaves evidently decreased after the shed was erected, and the contribution of Pb from atmospheric deposition to wheat tissue was significantly higher in the exposed treatment than in the non-exposed treatment (p < 0.05). This contrast test directly confirmed that atmospheric deposition was the main source of Pb in the wheat tissues. Therefore, taking measures to reduce the absorption of Pb by wheat from atmospheric deposition can effectively ensure food safety.

Comparative major components and health risks of toxic elements and polycyclic aromatic hydrocarbons of PM2.5 in winter and summer in Zhengzhou: Based on three-year data

Article

Nov 2018
ATMOS RES

In this study, 102 PM2.5 samples were collected from an urban site in Zhengzhou during winter and summer from 2012 to 2015. The meteorological impact, chemical characteristics, and health risks of the toxic elements and polycyclic aromatic hydrocarbons (PAHs) in PM2.5 were compared between the two seasons. PM2.5 pollution was relatively severe, especially in winter when meteorological conditions exhibited critical influence on PM2.5 concentration. NO3⁻, SO4²⁻, and NH4⁺ were the three most abundant species, accounting for 79% and 90% of total measured water-soluble inorganic ions in winter and summer, respectively. OC, EC, and SOC exhibited relatively high concentrations in winter, and SOC contributed >40% in OC in both seasons. The seasonality of PAHs was associated with PM2.5, with high contribution of four-ringed and five- to six-ringed PAHs in winter and summer, respectively. Fe, Al, Zn, Mg, Mn, and Pb were the most abundant elements in PM2.5 in both seasons. The levels of V, Ag, and As in the winter were almost 8.3, 6.2, and 2.7 times higher than those in summer, respectively. The cancer risk values of As, Ni, and Pb were all higher than 10⁻⁶ for adults and children in winter and summer. The non-carcinogenic risks of Pb, As, and Sb for children were beyond the safe level, especially from ingestion. PAHs, BaA, BaP, BbF, and DaA showed potential carcinogenic risk. BaA, BaP, and BbF showed higher cancer risk in winter than in summer for adults and children, whereas DaA showed higher cancer risk in summer than in winter. The calculated non-carcinogenic risk of BaP for children in winter was beyond the safe level. BAP caused high health risk for adults through inhalation but through ingestion and dermal contact for children.

Correlation Analysis, Transportation Mode of Atmospheric Mercury and Criteria Air Pollutants, with Meteorological Parameters at Two Remote Sites of Mountain and Offshore Island in Asia

Article

Full-text available

Nov 2016

This study presents a comparison of trace (Hg) and criteria (CO, SO2, NOx, O3 and PM10) air pollutants monitored at two remote sites with the same latitude but different altitude: Mt. Lulin and the Penghu Islands, in Taiwan from 2011 to 2012. A filtering technique was comprehensively applied to distinguish the climatic characteristics of the two remote sites, as well as to determine their discriminant factor. The concentrations of air pollutants monitored at Mt. Lulin were generally lower than those at the Penghu Islands, with the exception of O3 concentration. PM10 and NOx were the important factors that can distinguish two clusters of measurement data at the two remote sites, and a criteria discriminant factor of atmospheric parameters derived from these two air pollutants. For both high- and low-frequency patterns, the concentrations of NOx and PM10 exhibit significant differences between the two remote sites. However, O3 concentrations showed almost no differences between these two remote sites, implying that the pattern for the formation and transportation of O3 at these two sites resulted from similar mechanisms. Moreover, atmospheric mercury (TGM) had a very good linear correlation with CO. The diurnal variation of Hg concentration was dramatic at the Penghu Islands, while it appeared as low as the North Hemisphere background mercury concentration at Mt. Lulin, indicating that they were not formed via the mechanism modes. This study thus proposed “scenario mercury” and “background mercury” for interpreting this interesting phenomenon.

Source Sector Contributions to Aerosol Levels in Pakistan

Article

Full-text available

May 2015

Urban air pollution in Pakistan is a serious challenge and it causes significant damage to human health and ecosystems. This paper presents a modelling study using the Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem) to simulate the spatial distributions and temporal variations of aerosol concentrations over Pakistan, focusing on contributions of domestic emission sectors (transport, industry, residential, and energy) to mass concentrations of sulfate (SO4²⁻), nitrate (NO3⁻), ammonium (NH4⁺), black carbon (BC), and organic carbon (OC) during the months of January, April, July, and October in 2010. Sensitivity studies indicate that, averaged over January, April, July, and October of 2010, energy and industry sectors have the largest contributions to SO4²⁻ concentrations, each of which contributes about 10%–20% to SO4²⁻ over the polluted eastern Pakistan. The contributions from residential and transport sectors to NO3⁻ concentrations reach 40%–50% in central Pakistan. The residential sector has the highest contribution of 50%–80% to BC and OC loading in northeastern and southern Pakistan. Examination of sector contributions to aerosol levels in Lahore, the most polluted city in Pakistan, suggests that reductions in emissions in the residential sector should be an efficient measure for improving particulate matter air quality in this region.

Intercomparison of MODIS, MISR, OMI, and CALIPSO aerosol optical depth retrievals for four locations on the Indo-Gangetic plains and validation against AERONET data

Article

Full-text available

Apr 2015
ATMOS ENVIRON

Seasonal Variations of Aerosols in Pakistan: Contributions of Domestic Anthropogenic Emissions and Transboundary Transport

Article

Full-text available

Mar 2015

Air pollution has become a serious challenge for developing countries like Pakistan. Very scarce information is available regarding pollution levels in this geographic region. This study presents the first modelling work to simulate the spatial distribution and temporal variation of aerosol concentrations over Pakistan by using the Weather Research and Forecasting Model coupled with chemistry (WRF-Chem). Simulated aerosols species include sulfate, nitrate, ammonium, organic carbon, black carbon, and PM2.5 (particles with a diameter of 2.5 μm or less), which are evaluated against groundbased observations and satellite measurements. In year 2006, simulated PM2.5 concentrations averaged over northeastern Pakistan (71–74.5°E, 28–34°N) are 55, 48.5, 31.5, and 98 μg/m3 in January, April, July, and October, respectively. The simulated highest PM2.5 concentration in October results from the relatively low temperatures that favor nitrate formation as well as the lowest precipitation that leads to the smallest wet deposition of all aerosol species. The simulated lowest concentration of PM2.5 in July can be attributed to the largest precipitation associated with the South Asian summer monsoon. Sensitivity studies show that transboundary transport contributes to PM2.5 aerosol levels in northeastern Pakistan by 10–20% in January and April and by 10–40% in July and October of year 2006. Wind over India and Pakistan is found to be the major meteorological parameter that determines the transboundary aerosol transport.

Fog Research in China: An Overview

Article

Full-text available

May 2010

Fog can adversely affect human activity directly and indirectly, resulting in large losses both in terms of the local economy and lives. Much effort has been devoted to studies of fog across many areas of China, and in that context this paper aims to summarize climatic characteristics and review fog field experiments and their major results relating to fog mechanisms, physical properties and chemical characteristics. Progress in the application of remote sensing techniques and numerical simulation in fog research are also discussed. In particular, the effects of urbanization and industrialization on fog are highlighted. To end, perspectives on future fog research are outlined. The goal of this review paper is to introduce fog research in China to the global academic community and thus promote international collaboration on fog research. This is important because most papers on fog in China are published in Chinese, which are unreadable for the vast majority of non-Chinese researchers. Key wordsfog-climatic characteristics-fog observations-fog mechanisms-physicochemical characteristics-remote sensing-fog modeling

The MODIS Aerosol Algorithm, Products, and Validation

Article

Full-text available

Feb 2003

The MODerate resolution Imaging Spectroradiometer (MODIS) aboard both NASA's Terra and Aqua satellites is making near global daily observations of the earth in a wide spectral range. These measurements are used to derive spectral aerosol optical thickness and aerosol size parameters over both land and ocean. The aerosol products available over land include aerosol optical thickness at three visible wavelengths, a measure of the fraction of aerosol optical thickness attributed to the fine mode and several derived parameters including reflected spectral solar flux at top of atmosphere. Over ocean, the aerosol optical thickness is provided in seven wavelengths from 0.47 microns to 2.13 microns. In addition, quantitative aerosol size information includes effective radius of the aerosol and quantitative fraction of optical thickness attributed to the fine mode. Spectral aerosol flux, mass concentration and number of cloud condensation nuclei round out the list of available aerosol products over the ocean. The spectral optical thickness and effective radius of the aerosol over the ocean are validated by comparison with two years of AERONET data gleaned from 133 AERONET stations. 8000 MODIS aerosol retrievals colocated with AERONET measurements confirm that one-standard deviation of MODIS optical thickness retrievals fall within the predicted uncertainty of delta tauapproximately equal to plus or minus 0.03 plus or minus 0.05 tau over ocean and delta tay equal to plus or minus 0.05 plus or minus 0.15 tau over land. 271 MODIS aerosol retrievals co-located with AERONET inversions at island and coastal sites suggest that one-standard deviation of MODIS effective radius retrievals falls within delta r_eff approximately equal to 0.11 microns. The accuracy of the MODIS retrievals suggests that the product can be used to help narrow the uncertainties associated with aerosol radiative forcing of global climate.

Association of Fine Particulate Matter from Different Sources with Daily Mortality in Six U.S. Cities

Article

Full-text available

Nov 2000

Previously we reported that fine particle mass (particulate matter [less than and equal to] 2.5 microm; PM(2.5)), which is primarily from combustion sources, but not coarse particle mass, which is primarily from crustal sources, was associated with daily mortality in six eastern U.S. cities (1). In this study, we used the elemental composition of size-fractionated particles to identify several distinct source-related fractions of fine particles and examined the association of these fractions with daily mortality in each of the six cities. Using specific rotation factor analysis for each city, we identified a silicon factor classified as soil and crustal material, a lead factor classified as motor vehicle exhaust, a selenium factor representing coal combustion, and up to two additional factors. We extracted daily counts of deaths from National Center for Health Statistics records and estimated city-specific associations of mortality with each source factor by Poisson regression, adjusting for time trends, weather, and the other source factors. Combined effect estimates were calculated as the inverse variance weighted mean of the city-specific estimates. In the combined analysis, a 10 microg/m(3) increase in PM(2.5) from mobile sources accounted for a 3.4% increase in daily mortality [95% confidence interval (CI), 1.7-5.2%], and the equivalent increase in fine particles from coal combustion sources accounted for a 1.1% increase [CI, 0.3-2.0%). PM(2.5) crustal particles were not associated with daily mortality. These results indicate that combustion particles in the fine fraction from mobile and coal combustion sources, but not fine crustal particles, are associated with increased mortality.

Health effects of particles in ambient air

Article

Full-text available

Oct 2004
INT J HYG ENVIR HEAL

Unlabelled: A summary of a critical review by a working group of the German commission on Air Pollution Prevention of VDI and DIN of the actual data on exposure and health effects (excluding cancer) of fine particulate air pollution is presented. Exposure: Typical ambient particle concentrations for PM10 (PM2.5) in Germany are in the range of 10-45 (10-30) microg/m3 as annual mean and 50-200 (40-150) microg/m3 as maximum daily mean. The ratio of PM2.5/PM10 generally amounts between 0.7 and 0.9. Health effects: During the past 10 years many new epidemiological and toxicological studies on health effects of particulate matter (PM) have been published. In summary, long-term exposure against PM for years or decades is associated with elevated total, cardiovascular, and infant mortality. With respect to morbidity, respiratory symptoms, lung growth, and function of the immune system are affected. Short-term studies show consistant associations of exposure to daily concentrations of PM with mortality and morbidity on the same day or the subsequent days. Patients with asthma, COPD, pneumonia, and other respiratory diseases as well as patients with cardio-vascular diseases and diabetes are especially affected. The strongest associations are found for PM2.5 followed by PM10, with no indication of a threshold value for the health effects. The data base for ultra fine particles is too small for final conclusions. The available toxicological data support the epidemiological findings and give hints as to the mechanisms of the effects. Conclusion: The working group concludes that a further reduction of the limit values proposed for 2005 will substantially reduce health risks due to particulate air pollution. Because of the strong correlation of PM10 with PM2.5 at most German sites there is no specific need for limit values of PM2.5 for Germany in addition to those of PM10.

Source apportionment and characterization of particulate matter (PM10) in urban environment of Lahore

Article

May 2014

Khan Alam

Atmospheric pollution has become a serious problem in the developing world, due to rapid urbanization and industrialization. The rapidly growing urban population, and consequent rise in industrial, agricultural, and transportation activities, as well as the construction and burning of cooking fuels, has resulted in the deterioration of air quality, due to elevated levels of particulate matter in the ambient environment. Sources of various pollutants and their characterization have been carried out in the present study in the metropolitan city Lahore. This study is based upon measurements of particulate matter (PM10) pollution at an urban site of Lahore. The carbonaceous species (Elemental carbon, organic carbon, total carbon) and trace metals were measured in PM10 samples. PM10 concentrations varied from 254µg/m3 to 555µg/m3 with an average of 406µg/m3. The elemental carbon (EC) concentration varied from 3µg/m3 to 56µg/m3 with an average of 21µg/m3. While the organic carbon (OC) concentrations varied from 21µg/m3 to 212µg/m3 with an average of 63µg/m3. The OC/EC ratio varied from 1.5 – 7.6 with an average of 3.9, indicating a contribution of both biogenic and secondary aerosol formation. A good correlation was also observed between EC and OC (R2=0.81) indicating their common origin. Main sources identified during the study are industrial dust (18.2% of PM10), Vehicular emission (26.5 % of PM10), bio mass fuel (24.3% of PM10) and re-suspended dust (4.6 % of PM10).

Review of air pollution and health impacts in Malaysia

Article

Jun 2003

Rafia Afroz

In the early days of abundant resources and minimal development pressures, little attention was paid to growing environmental concerns in Malaysia. The haze episodes in Southeast Asia in 1983, 1984, 1991, 1994, and 1997 imposed threats to the environmental management of Malaysia and increased awareness of the environment. As a consequence, the government established Malaysian Air Quality Guidelines, the Air Pollution Index, and the Haze Action Plan to improve air quality. Air quality monitoring is part of the initial strategy in the pollution prevention program in Malaysia. Review of air pollution in Malaysia is based on the reports of the air quality monitoring in several large cities in Malaysia, which cover air pollutants such as Carbon monoxide (CO), Sulphur Dioxide (SO2), Nitrogen Dioxide (NO2), Ozone (O3), and Suspended Particulate Matter (SPM). The results of the monitoring indicate that Suspended Particulate Matter (SPM) and Nitrogen Dioxide (NO2) are the predominant pollutants. Other pollutants such as CO, O(x), SO2, and Pb are also observed in several big cities in Malaysia. The air pollution comes mainly from land transportation, industrial emissions, and open burning sources. Among them, land transportation contributes the most to air pollution. This paper reviews the results of the ambient air quality monitoring and studies related to air pollution and health impacts.

The influence of the organic aerosol component on CCN supersaturation spectra for different aerosol types

Article

Jan 2002
TELLUS B

Abstract This paper describes the effect of the presence of water-soluble organic compounds (WSOC) in aerosol particles on the aerosol critical supersaturation as defined by the Köhler theory and on cloud condensation nuclei (CCN) number concentration. Taking into account both the soluble mass increase and the surface tension depression due to WSOC, we calculated a substantial decrease of the aerosol critical supersaturation, which results in a large increase in CCN number concentration. CCN supersaturation spectra were computed for three different aerosol types: marine, rural and urban. The increase of CCN number concentration in the presence of WSOC (with respect to the case when only the inorganic aerosol compounds are considered) varies with aerosol type, with an increase up to 13% in the marine case, up to 97% in the rural case, and up to 110% in the urban case, for the supersaturation range typical of atmospheric conditions.

Annual and Seasonal Variations of Trace Metals in Atmospheric Suspended Particulate Matter in Islamabad, Pakistan

Article

May 2008

Total Suspended particulate matter (TSP) in urban atmosphere of Islamabad was collected using a high volume sampling technique for a period of one year. The nitric acid–perchloric acid extraction method was used and the metal contents were estimated by atomic absorption spectrophotometer. The highest mean concentration was found for Ca at 4.531µg/m3, followed by Na (3.905µg/m3), Fe (2.464µg/m3), Zn (2.311µg/m3), K (2.086µg/m3), Mg (0.962µg/m3), Cu (0.306µg/m3), Sb (0.157µg/m3), Pb (0.144µg/m3) and Sr (0.101µg/m3). On an average basis, the decreasing metal concentration trend was: Ca > Na > Fe > Zn > K > Mg > Cu > Sb > Pb > Sr > Mn > Co > Ni > Cr > Li > Cd ≈ Ag. The TSP levels varied from a minimum of 41.8 to a maximum of 977µg/m3, with a mean value of 164µg/m3, which was found to be higher than WHO primary and secondary standards. The correlation study revealed very strong correlations (r > 0.71) between Fe–Mn, Sb–Co, Na–K, Mn–Mg, Pb–Cd and Sb–Sr. Among the meteorological parameters, temperature, wind speed and pan evaporation were found to be positively correlated with TSP, Ca, Fe, K, Mg, Mn and Ag, whereas, they exhibited negative relationships with relative humidity. On the other hand, Pb, Sb, Zn, Co, Cd and Li revealed significant positive correlations with relative humidity and negative with temperature, wind speed and pan evaporation. The major sources of airborne trace metals identified with the help of principle component analysis and cluster analysis were industrial emissions, automobile exhaust, biomass burning, oil combustion, fugitive emissions, resuspended soil dust and earth crust. The TSP and selected metals were also studied for seasonal variations, which showed that Na, K, Zn, Cu, Pb, Sb, Sr, Co and Cd peaked during the winter and remained lowest during the summer, while Ca, Fe, Mg and Mn were recorded highest during the spring.

Suspended particulate matter and its relations to the urban climate in Dar es Salaam, Tanzania

Article

Aug 2004
ATMOS ENVIRON

Relationships between sources and levels of particulate matter and climatic parameters (urban heat island intensity, wind speed, temperature and relative humidity) were investigated in the coastal city of Dar es Salaam, Tanzania's largest city. Measurements were made during the wet and dry seasons of 2001 at an urban and a rural site. Five elements were used to represent different sources: K in fine particles (biomass), Zn in fine particles (industry), Cl in coarse particles (sea spray), Ti in coarse particles (soil) and Pb in fine particles (traffic). The concentrations of these elements varied considerably between the urban and rural site during both the wet and dry season, with the urban site in the dry season having the highest concentrations. Diurnal differences are also apparent, although not as straightforward. In an attempt to explain these differences, correlations between all elements and the climatic parameters were investigated. The results show that the nocturnal urban heat island intensity was positively correlated and wind speed negatively correlated with particulate levels, presumably due to the increased atmospheric stability.

Atmospheric Chemistry and Physics : From Air Pollution to Climate Change / J.H. Seinfeld, S.N. Pandis.

Article

Contenido: 1) La atmósfera; 2) Componentes en la atmósfera; 3) Cinética química; 4) Radiación atmosférica y fotoquímica; 5) Química de la estratosfera; 6) Química de la troposfera; 7) Química de la fase acuosa de la atmósfera; 8) Propiedades de los aerosoles atmosféricos; 9) Dinámica de partículas simples de aerosol; 10) Termodinámica de aerosoles; 11) Nucleación; 12) Aspectos de la transferencia de masa de química atmosférica; 13) Dinámica de las poblaciones de aerosoles; 14) Aerosoles atmosféricos orgánicos; 15) Interacción de aerosoles con la radiación; 16) Meteorología a escala local; 17) Física de las nubes; 18) Difusión atmosférica; 19) Deposición seca; 20) Deposición húmeda; 21) Circulación general de la atmósfera; 22) Ciclos globales del sulfuro y del carbón; 23) Clima y composición química de la atmósfera; 24) Aerosoles y clima; 25) Modelos químicos de transporte atmosférico; 26) Modelos estadísticos. Apéndices.

Residential proximity to industry and adverse birth outcomes

Article

Oct 1999

We studied birth statistics in women living at varying proximity to major steel and petrochemical industries in Teesside, UK. We found no evidence to support the hypothesis that living close to these major industries led to adverse birth outcomes.

Effect of PM10, Pollution in Bangkok on Children with and Without Asthma

Article

Mar 2004

This study aimed to investigate the effects of PM10 concentrations exceeding the Thai national standard (24-hr average, >120 microg/m3) on daily reported respiratory symptoms and peak expiratory flow rate (PEFR) of schoolchildren with and without asthma in Bangkok. The 93 asthmatic and 40 nonasthmatic schoolchildren were randomly recruited from a school located in a highly congested traffic area. Daily respiratory symptoms and PEFR of each child were evaluated and recorded in the diary for 31 successive school days. During the study period, 24-hr average PM10 levels ranged between 46-201 microg/m3. PM10 levels exceeded 120 microg/m3 for 14 days. We found that when PM10 levels were >120 microg/m3, the daily reported nasal irritation of asthmatic children was significantly higher than when PM10 levels were < or =120 microg/m3. In addition, when PM10 levels were >120 microg/m3, nonasthmatic children had a significantly higher daily reported combination of any respiratory symptoms. PEFR did not change with different ambient PM10 levels in both groups. This study suggests that elevated levels of PM10 concentrations in Bangkok affect respiratory symptoms of schoolchildren with and without asthma.

Distribution of lead in relation to size of airborne particulate matter in Islamabad, Pakistan

Article

Feb 2004

Airborne particulate matter (PM) collected from two sampling stations in Islamabad, Pakistan, was analyzed for lead content and size gradation. A high volume air sampler was used to trap particulates on glass fiber filters for 8-12 h on a daily basis. Lead was estimated using a nitric acid digestion based AAS method on 44 samples from station 1 and 61 samples from station 2. Particle size fractions were categorized as <2.5, 2.5-10, 10-100 and >100 microm. The correlation between lead concentration and particle size was investigated. The results from two stations indicated average airborne lead concentrations of 0.505 and 0.185 microg/m3. Enhanced levels of lead were measured at a maximum of 4.075 microg/m3 at station 1 and 4.000 microg/m3 at station 2. PM < 2.5 and PM > 100 were found to constitute the local atmosphere in comparable proportions. A comparison of the lead levels is made with the existing permissible levels of this element laid down by different international agencies.

Screening of Urban Aerosol Particulate Composites for Selected Metal Distribution and Their Dependence on Meteorological Parameters

Article

Nov 2004

Local atmospheric aerosol particulate samples, collected as composites on daily 6-12 hour basis, at Quaid-i-Azam University campus, Islamabad, Pakistan, using high volume sampling technique, were analysed for Pb, Na, K, Fe, Mn, Cd, Cr, Ni, Zn and Co by FAAS method. The monitoring period ran from October, 2001 through March, 2002, with a total of 105 samples collected on cellulose filters, treated in part with the HNO3-based wet digestion method for metal quantification, and for particle size distribution separately. The metal content of the aerosols was examined in relation to dependence on meteorological parameters, such as temperature, relative humidity, wind speed, sun shine and pan evaporation. Statistical correlation analysis was conducted for multiple metal pairs in aerosols, and the data were examined in relation to meteorological parameters and relevant aerosol particle size fractions. The study revealed no viable strong correlation between the meteorological parameters and metal levels; in general, however, a significant positive correlation was found for temperature. A strong positive correlation was observed for PM<25 and PM2.5-10. For coarse particles (PM10-100 and PM>100), however, a negative correlation was observed. The levels of Na, K, Fe and Zn were found in the range of 1-5 microg/m3 while those for the rest of the metals in the sub microg/m3 range. Principal component analysis and cluster analysis were performed on dataset for source identification and appointment. Largest contribution (33%) was shown by the industrial emissions followed by traffic/road dust (16.7%).

Spatial variations in selected metal contents and particle size distribution in an urban and rural atmosphere of Islamabad, Pakistan

Article

Feb 2006

Spatial variations in total suspended particulate matter (TSP) were investigated for distribution of metals and particle size fractions in the urban and rural atmosphere of Islamabad, Pakistan. The metals Na, K, Fe, Mn, Pb, Cd, Cr, Zn, Ni and Co, and the particle fractions <2.5, 2.5-10, 10-100 and >100 microm were included in the study. TSP samples were trapped on glass fibre filters using high volume samplers and quantification of metals was done using Atomic Absorption Spectrometry employing HNO(3) based wet digestion. At the urban site, Na was dominant at 2.384 microg/m(3) followed by K, Fe and Zn with 0.778, 0.667 and 0.567 microg/m(3) as mean concentrations, respectively. The metal levels for the rural site ranged from 0.002 microg/m(3) for Cd to 1.077 microg/m(3) for Na. However, compared with the urban site, mean Pb concentration showed an almost two-fold enhancement, i.e., 0.163 Vs. 0.327 microg/m(3). Metals and particle size source identification was done using Principal Component Analysis and Cluster Analysis. Five sources were traced out for the urban site: industrial, soil, automobile emissions, metallurgical industries and excavation activities. For the rural site, four sources were recorded: agricultural, automotive emissions, excavation activities and metallurgical units. Collectively, for both the sites, PM(10-100) emerged as a major contributor to TSP, followed by PM(2.5-10), PM(<2.5) and PM(>100) in that order. The metals showed in general positive relationship with fine particulate fractions (PM(2.5-10), PM(<2.5)), and negative correlation with coarse fractions (PM(10-100), PM(>100)). Comparison with the corresponding data from various Asian sites revealed that the levels of Na, K, Fe, Mn, Co and Ni for the present study were lower than those reported for grossly polluted cities of the world.

Statistical analysis of atmospheric trace metals and particulate fractions in Islamabad, Pakistan

Article

Aug 2007
J HAZARD MATER

Airborne suspended particulate matter was collected on glass fibre filters in urban atmosphere of Islamabad, Pakistan, using high volume sampler. The particulate samples were analysed for 10 selected metals (Fe, Na, Zn, K, Pb, Mn, Cr, Ni, Co and Cd) by FAAS method. Maximum mean contribution was noted for Fe (1.761microg/m(3)), followed by Na (1.661microg/m(3)), Zn (1.021microg/m(3)), K (0.488microg/m(3)) and Pb (0.128microg/m(3)). The particle size determination on vol.% basis for nine fractions (PM(<1.0), PM(1.0-2.5), PM(2.5-5), PM(5-10), PM(10-15), PM(15-25), PM(25-50), PM(50-100) and PM(>100)) was carried out using Mastersizer. PM(5.0-10) were found to be most abundant in the local atmosphere followed by PM(2.5-5.0) and PM(15-25) while coarse/giant particles (PM(50-100) and PM(>100)) showed lower contribution. The trace metals were found to be mainly associated with smaller particulate fractions up to PM(10-15). Among the climatic parameters temperature has significant relationship with fine particles and airborne metal levels while relative humidity showed negative correlation. The source identification was carried out by principal component analysis and cluster analysis. Five metal sources were identified: industrial, vehicular emissions, metallurgical operations, garbage incineration and soil derived dust. The metal levels were also compared with those reported for other rural and urban parts around the world.

Influence of aerosol spectrum and air pollutants on fog formation in urban environment of megacity Delhi, India

Article

May 2008
ENVIRON MONIT ASSESS

Urban areas are facing increasing fog frequencies that may result due to increased air pollution emanating from variety of sources. The increased pollution levels may lead to the atmospheric reactions resulting into the formation of secondary pollutants that may also lead to increased aerosol number concentrations (ANC) in the atmosphere. This could cause enhanced water aerosols in the presence of favourable meteorological conditions and high relative humidity. This study deals with the atmospheric pollution and visibility during winter season of megacity Delhi in order to assess the relationship between the two specifically during fog episodes. Thus, this study analyses the levels of air pollutants, aerosol spectrum and meteorological conditions during one week each in the winter season of the years 2004 and 2006 in order to have an improved understanding of their role in fog formation in mega-city Delhi. More than 300 h of measurements which included episodes of dense, thick and moderate fogs of about 25 h, were studied. The measurements cover most of the accumulation mode and greater size spectrum of aerosols. Thus, the analysis is performed for the entire period, specifically, before the fog sets up, during and afterwards. In general, the relatively small variations in number concentration show larger variations in visibility prior and post dense fog formation than during dense fog episodes. Preliminary analysis of monthly averaged RSPM (Respirable Suspended particulate Matter or PM(10)) concentration values for four winter months for a period of 6 years (1996-2001) and visibility did not show a good correlation with total occurrences of fog. However, daily averaged RSPM concentration showed a good correlation with the occurrences of thick fog. Diurnal variation of Sulfur-dioxide and Nitrogen dioxide were found to have inverse relationship with visibility during fog which may be due to formation of secondary pollutants such as sulfate and to a lesser extent nitrates. Amongst, the daily averaged concentrations of all the criteria pollutants, RSPM was found to be best correlated with the fog in comparison to other pollutants.

the Indo-Gangetic plains and validation against AERONET data Health Effects of Particles in Ambient 349

Jan 2004

G H M Kreyling
W G Rauchfuss

the Indo-Gangetic plains and validation against AERONET data. Atmos. Environ. 111: G.H.M., Kreyling, W.G. and Rauchfuss, K. (2004). Health Effects of Particles in Ambient 349

The Collection 6 MODIS aerosol products over land and ocean

Jan 2013
2989-356

The Collection 6 MODIS aerosol products over land and ocean. Atmos. Meas. Tech. 6, no. 355 11 (2013): 2989. 356

Variation in Fog Intensity/Duration and El Nino

Jan 2004

F S Saeed
A Younas

Saeed, F.S. and Younas, A. (2004). Variation in Fog Intensity/Duration and El Nino. Pakistan J.

The world health report 2002-reducing risks

Jan 2002

World Health Organization (2002). The world health report 2002-reducing risks, promoting 424

Jan 1994
207-216

Angeles Los
County

Los Angeles County, California 1994-1996. Environ. Health Perspect. 111:207-216.

CALIPSO aerosol optical depth retrievals for four locations on 325 the Indo-Gangetic plains and validation against AERONET data

326-113

Misr Modis
Omi

MODIS, MISR, OMI, and CALIPSO aerosol optical depth retrievals for four locations on 325 the Indo-Gangetic plains and validation against AERONET data. Atmos. Environ. 111: 326 113-126.

Ozone, area social conditions

Jan 2004
369

M S O'neill
D Loomis
V H Borja

O'Neill, M.S., Loomis, D. and Borja V.H. (2004). Ozone, area social conditions, and mortality in 369

Application SEM to Analysis Formation Characteristic of 420

Jan 2009

Q C Wang
Y H Luo

Wang, Q. C. and Luo, Y. H. (2009). Application SEM to Analysis Formation Characteristic of 420

Characterization of PM10 and PM2.5 Source Profiles of Fugitive Dust in Zhengzhou, China

Abstract

No full-text available

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