Dust Resuspension Research Articles

Contribution of road dust from Low Impact Development (LID) construction sites to atmospheric pollution from heavy metals

The re-suspension of road dust due to intense Low Impact Development (LID) construction activities may be a major contributor to atmospheric metal pollution. However, the distribution characteristics, mobility potential, and pollutant load of atmospheric particles at LID construction sites are not clear. Consequently, management practices to mitigate air pollution from LID construction are lacking. We investigated the atmospheric metal pollution from road dust produced during different construction stages of rain gardens and porous pavements and estimated the ecological risks posed by the heavy metals. Although concentrations of heavy metals in road dust at LID construction sites were lower than at sites without LID construction, the ecological risks posed by the atmospheric heavy metals at LID construction sites were generally higher due to the greater mass of road dust produced during LID construction. Hence, LID management practices should focus on the removal of road dust, especially finer particles (<44 μm) produced during early construction stages. In roads, the zones influenced by LID construction is related to road types based on traffic volume; these road types in descending order of zone influenced by LID construction are: arterial road (400–600 m) > collector road (100–150 m) > access road (50–100 m) > laneway (30–50 m). Based on the study sites, we estimate LID construction in China will contribute 2.31 and 6.23 times as much as the current load of atmospheric particles by 2020 and 2030; and we project atmospheric heavy metals will be 1.45–2.18 and 2.82–4.73 times greater than the current load by 2020 and 2030 from the intense LID construction. Based on our results, several regulatory recommendations are presented to mitigate air pollution at LID construction sites.

High resolution vehicular PM10 emissions over megacity Delhi: Relative contributions of exhaust and non-exhaust sources

Exposure to particulate matter (PM) from traffic can cause adverse health risks. Recent studies project an increase in non-exhaust emissions in the future despite a reduction in exhaust emissions. While there is a lot of research on exhaust emissions, the challenges remain to quantify non-exhaust emissions, especially in developing countries. In this work, an approach has been developed, and on-road vehicular non-exhaust PM emissions are estimated due to brake wear, tyre wear, road wear and resuspension, at very high resolution (100 m2) over an Indian megacity Delhi. Further, the relative contribution of non-exhaust emissions to the total vehicular emission was also calculated. The total PM10 emissions in megacity Delhi were 31.5 Gg/year, which is mainly dominated by the non-exhaust sources. The non-exhaust emissions were found to be six times (86%) of the exhaust emission (14%). The highest contribution to the total vehicular PM emission comes from the cars (34%) followed by buses (23%) and heavy commercial vehicles (HCVs, 17%), which is dominated by resuspension of dust. Cars and buses contribute less to exhaust emissions and more to non-exhaust emissions. Majors roads are the largest contributors to the total emissions in Delhi. The emissions from HCVs, diesel cars along with the other diesel vehicles result in diesel vehicles contributing more than the petrol vehicles to both exhaust and non-exhaust emissions. As India target to reduce PM pollution under the national clean air program, the current study will be useful to plan a suitable intervention to mitigate air pollution and associated health impacts.

Airborne, Vehicle-Derived Fe-Bearing Nanoparticles in the Urban Environment: A Review.

Airborne particulate matter poses a serious threat to human health. Exposure to nanosized (<0.1 μm), vehicle-derived particulates may be hazardous due to their bioreactivity, their ability to penetrate every organ, including the brain, and their abundance in the urban atmosphere. Fe-bearing nanoparticles (<0.1 μm) in urban environments may be especially important because of their pathogenicity and possible association with neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. This review examines current knowledge regarding the sources of vehicle-derived Fe-bearing nanoparticles, their chemical and mineralogical compositions, grain size distribution and potential hazard to human health. We focus on data reported for the following sources of Fe-bearing nanoparticles: exhaust emissions (both diesel and gasoline), brake wear, tire and road surface wear, resuspension of roadside dust, underground, train and tram emissions, and aircraft and shipping emissions. We identify limitations and gaps in existing knowledge as well as future challenges and perspectives for studies of airborne Fe-bearing nanoparticles.

Effects of construction activities on the planetary boundaries

This study presents a part of an ongoing research on construction in developing countries and the need to operate within planetary boundaries for sustainable development. It is a desk-research and it uses the already established planetary boundary concept to provide insights on the negative consequences of construction activities on planet earth. Some of the harmful effects of construction activities include: production of re-suspended dust particles and bituminous aerosols during construction, emission of greenhouse gases from embodied energy in buildings, rapid loss of biodiversity, unsustainable disposal of domestic and industrial waste into oceans and other water bodies and the unsustainable use of limited fresh water. The paper concludes that continued unsustainable construction activities will have devastating and irreversible effects on a planetary scale.

Environmental Impact Assessment of Banagrass-Based Cellulosic Ethanol Production on Hawaii Island: A Spatial Analysis of Re-Suspended Soil Dust and Carbon Dioxide Emission

Environmental impacts from the development of banagrass (Pennisetum purpureum)-based ethanol production on Hawaii Island may create air quality problems. Air pollutants considered in this study include re-suspended soil dust (also known as PM2.5 and PM10) and carbon dioxide (CO2) emission. The resulting pollutant emissions are then compared against the Federal Prevention of Significant Deterioration (PSD) significant standard for the environmental impact assessment. This study combines GIS and a mathematical computational model to logically and effectively examine potential spatial impacts of ethanol development on air quality on Hawaii Island. This study found that mechanical harvesting of banagrass generates higher dust emission than other agricultural crops. The total PM10 emission of 248.18 tons per year was found statistically equivalent to the PSD significant permitting requirement limit of 250 tons per year (tpy) and thus considered as a major stationary source of fugitive dust pollution. The annual CO2 emission amount of 19,371.72 tons is less than the PSD significant permitting requirement of 75,000 tons of CO2 per year. As a result, this estimated amount is not considered as a major stationary source of pollution.

Assessing the association between fine particulate matter (PM2.5) constituents and cardiovascular diseases in a mega-city of Pakistan

Concerning PM2.5 concentrations, rapid industrialization, along with increase in cardiovascular disease (CVD) were recorded in Pakistan, especially in urban areas. The degree to which air pollution contributes to the increase in the burden of CVD in Pakistan has not been assessed due to lack of data. This study aims to describe the characteristics of PM2.5 constituents and investigate the impact of individual PM2.5 constituent on cardiovascular morbidity in Karachi, a mega city in Pakistan. Daily levels of twenty-one constituents of PM2.5 were analyzed using samples collected at two sites from fall 2008 to summer 2009 in Karachi. Hospital admission and emergency room visits due to CVD were collected from two large hospitals. Negative Binominal Regression was used to estimate associations between pollutants and the risk of CVD. All PM2.5 constituents were assessed in single-pollutant models and selected constituents were assessed in multi-pollutant models adjusting for PM2.5 mass and gaseous pollutants. The most common CVD subtypes among our participants were ischemic heart disease, hypertension, heart failure, and cardiomyopathy. Extremely high levels of PM2.5 constituents from fossil-fuels combustion and industrial emissions were observed, with notable peaks in winter. The most consistent associations were found between exposure to nickel (5–14% increase per interquartile range) and cardiovascular hospital admissions. Suggestive evidence was also observed for associations between cardiovascular hospital admissions and Al, Fe, Ti, and nitrate. Our findings suggested that PM2.5 generated from fossil-fuels combustion and road dust resuspension were associated with the increased risk of CVD in Pakistan.

Human health risks assessment for airborne PM10-bound metals in Seoul, Korea.

Seoul, the capital city of South Korea, is the social, political, and economic center of the country. Significant levels of PM10-bound As metalloid and metals have been found in the city, which poses possible adverse health risks to the residents from inhalation exposure. Therefore, this study focuses on the health risk assessment of age-dependent cancer and non-cancer using exposure pathway and human respiratory tract (HRT) mass deposition models. In the case of non-cancer risks, the hazard quotient (HQ) of As via ingestion exposure and the hazard index (HI) was found to be significant (> 1) for the children. The cancer risks through ingestion pathway (CRing) were estimated in the order of 10-4 and 10-5 for children and adult groups, respectively. The overall CRing levels for children were estimated slightly higher than the acceptable level of cancer risk (1 × 10-4) at all locations throughout the study area. Moreover, the risks of cancer through the inhalation (CRinh) and incremental lifetime cancer risks (ILCR) due to HRT mass deposition were found to be significant (> 10-6) and with very small discrepancy in risk levels for both age groups. Furthermore, possible sources of the PM10-bound metalloid (As) and metals were predicted through correlation, principal component, and enrichment factor analysis. The results of source apportionment study indicated the local anthropogenic emission sources (vehicular, biomass/coal/oil combustion, industrial), road dust re-suspension, and trans-boundary sources were responsible for the pollution levels in Seoul, South Korea. The health risks can be minimized by reducing the pollution levels of particulate matter at source.

The influence of roadside trees on the diffusion of road traffic pollutants and their magnetic characteristics in a typical semi-arid urban area of Northwest China

Leaf samples of Juniperus formosana were collected from an open road environment, in order to establish how particulate matter (PM) generated by vehicles was dispersed in both horizontal and vertical directions. Sampling was conducted at sites with trees of varying height and configuration adjacent to a major road in Lanzhou, Gansu Province, Northwest China. The concentration of remanence-bearing ferrimagnets in the leaf samples was estimated from measurements of Saturation Isothermal Remanent Magnetization (SIRM), while the weight of particles deposited on the leaves and their elemental composition were determined at different heights and in different directions relative to the road. The PM on the surface of needles was predominantly influenced by traffic emissions and by dust resuspension. Rows of roadside trees, as opposed to solitary trees, were more effective at intercepting PM and thus in filtering road traffic pollution. The results indicate that Juniperus formosana needles may be an effective bio-sensor for monitoring variations in the spatial diffusion of road pollutants.

Trace element characterization of fine particulate matter and assessment of associated health risk in mining area, transportation routes and institutional area of Dhanbad, India.

Samples of PM2.5 were collected on PTFE filters at 11 monitoring stations in Dhanbad, India, from March, 2014, to February, 2015, for the quantification of 10 PM2.5-bound trace elements by using ICP-OES, source apportionment by using principal component analysis and health risks posed by PM2.5-bound trace elements by using health risk assessment model developed by US EPA. The average annual PM2.5 concentration (149 ± 66µg/m3) exceeded the national ambient air quality standards by factor of 3.7, US EPA national ambient air quality standards by factor of 10 and WHO air quality guidelines by factor of 15. The sum total of average annual concentration of all PM2.5-bound trace elements was found to be 3.206µg/m3 with maximum concentrations of Fe (61%), Zn (21%) and Pb (11%). Coal mining, coal combustion, vehicular emission, tyre and brake wear and re-suspension of road dust were identified as dominant sources of PM2.5-bound trace elements from the results of correlation and chemometric analysis. The significantly high HQ values posed by PM2.5-bound Co and Ni and intensification of HI values (15.7, 10.8 and 8.54 in mining area, transportation routes and institutional area, respectively) for multielemental exposure indicate high potential of non-carcinogenic health risk associated with inhalation exposure. The carcinogenic health risk due to multielemental exposure in mining area (2.27 × 10-4) and transportation routes (1.57 × 10-4) for adults were significantly higher than threshold value indicating the vulnerability of adults toward inhalation-induced carcinogenic risk posed by PM2.5-bound trace elements.

Levels of trace elements in PM10 collected at roadsides of Addis Ababa, Ethiopia, and exposure risk assessment.

Estimation of personal exposure to air pollution is needed to identify high-risk population and to develop mitigation strategies. In this study, an assessment of the potential effects of short-term exposure to PM10 and the elements bound within PM10 was conducted. Samples were obtained from the ten sub-cities of Addis Ababa (three sampling points from each) during the commuting time (traffic congestion and taxi queues). A particle counter consisting of a portable sampling unit with multi-fraction dust samplers was used for sample collection. The elemental composition was analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The mean concentrations of PM10 ranged from 206 to 308μgm-3. The highest concentrations of pollutants were found in the major open-market part of the city, Addis Ketema. The lowest concentrations were found at the old-town, Arada sub-cities. The concentration of trace elements (Fe, Cd, As, Cr, Pb, B, Ni, Co, Sn, Cu, and Zn) bound in PM10 ranged from below detectable limit to 0.981μgm-3. Regardless of the sampling sub-city, the overall patterns of the mean concentration of elements bound in PM10 were found in the following increasing order of Cr < Cd < As < Co < Ni < Cu < Fe < Pb < Sn < B < Zn < Mn. The results showed that the primary source of Zn, Cr, and Cd may be emissions from on-road vehicles, tire and brake wear. Pb originates mainly from industries and suspended soil dust at the roadside, whereas As, Mn, and B are associated with dust resuspension and biomass and biofuel combustion, respectively. The carcinogenic and non-carcinogenic risks due to chronic exposure to trace elements bound in PM10 at the roadside were assessed in accordance with the U.S. Environmental Protection Agency (US EPA) guidelines. It was determined that Mn, As, and Cd contributed substantially to the inducement of non-carcinogenic health problems to children and adults as a result of exposure while in close proximity to the roadsides.

Settled Dust from Urban and Suburban Roads in an Industrial City Area: Location and Seasonal Differences in Metal Content.

Settled road dust, present on all roads surfaces in a relatively high abundance, is a complex of particles-ranging from nanosized to microsized-from both natural and anthropogenic sources and may pose possible risk to the biosphere as well as influence the atmosphere because of the road dust resuspension. Geographical and seasonal differences in heavy metal content of the settled road dust were studied at two sites: urban site with a heavy traffic in the industrial city of Ostrava, Czech Republic and suburban site of Ostrava with a negligible traffic load in settlement Ludgeřovice. Dust samples were collected monthly during the period from March to October 2015. Obtained dust samples were homogenized and subsequently analyzed by Inductively Coupled Plasma Atomic Emission Spectroscopy; the results were then assessed by multivariate statistical methods (Principal components analysis, Factorial analysis on mixed data). The difference in the content of Ba, Cr, Cu, Mn, Ni, Pb, Sb, Sn, V, and Zn was explainable mainly by the factor of the site only the content of Fe was significantly dependent on the month of sampling. The contents of the particular elements and the correlations found among them confirm the assumption that heavy metals detected in the road dust samples from the urban site most likely originated primarily from the traffic-and particularly from the non-combustion processes.

Numerical analysis of loss of vacuum accident (LOVA) and preliminary discussion about dust resuspension for CFETR

Loss of vacuum accident (LOVA) is the air ingress into the vacuum vessel (VV) due to the failure of components. The high speed air jet flow induced by the pressure difference between the ambient condition and the in-vessel condition may cause the dust migration, re-suspension bring risk to the integrity of components and radioactive release. The present work deals with the computational fluid dynamics (CFD) modeling of airflow characteristics in different scenarios during the LOVA for CFETR. Then, forces applied on the deposited particles are investigated, based on which the preliminary discussion are carried out to analyze the possibility of dust resuspension in various LOVA scenarios. The results show that the break location, break size and the operational status during the LOVA have significant influence on the key parameters related to airflow forces such as the friction velocity. Furthermore, the airflow force gradually plays the dominate role as the particle diameter increases. It preliminarily demonstrates the possibility of dust resuspension as the particle diameter changing. The results can provide references to study the dust re-suspension and implement accident mitigation measures.

Polyols and glucose particulate species as tracers of primary biogenic organic aerosols at 28 French sites

Abstract. A growing number of studies are using specific primary sugar species, such as sugar alcohols or primary saccharides, as marker compounds to characterize and apportion primary biogenic organic aerosols (PBOAs) in the atmosphere. To better understand their annual cycles, as well as their spatiotemporal abundance in terms of concentrations and sources, we conducted a large study focusing on three major atmospheric primary sugar compounds (i.e., arabitol, mannitol, and glucose) measured in various environmental conditions for about 5300 filter samples collected at 28 sites in France. Our results show significant atmospheric concentrations of polyols (defined here as the sum of arabitol and mannitol) and glucose at each sampling location, highlighting their ubiquity. Results also confirm that polyols and glucose are mainly associated with the coarse rather than the fine aerosol mode. At nearly all sites, atmospheric concentrations of polyols and glucose display a well-marked seasonal pattern, with maximum concentrations from late spring to early autumn, followed by an abrupt decrease in late autumn, and a minimum concentration during wintertime. Such seasonal patterns support biogenic emissions associated with higher biological metabolic activities (sporulation, growth, etc.) during warmer periods. Results from a previous comprehensive study using positive matrix factorization (PMF) based on an extended aerosol chemical composition dataset of up to 130 species for 16 of the same sample series have also been used in the present work. The polyols-to-PMPBOA ratio is 0.024±0.010 on average for all sites, with no clear distinction between traffic, urban, or rural typology. Overall, even if the exact origin of the PBOA source is still under investigation, it appears to be an important source of particulate matter (PM), especially during summertime. Results also show that PBOAs are significant sources of total organic matter (OM) in PM10 (13±4 % on a yearly average, and up to 40 % in some environments in summer) at most of the investigated sites. The mean PBOA chemical profile is clearly dominated by contribution from OM (78±9 % of the mass of the PBOA PMF on average), and only a minor contribution from the dust class (3±4 %), suggesting that ambient polyols are most likely associated with biological particle emissions (e.g., active spore discharge) rather than soil dust resuspension.

Lattice Boltzmann method simulation of SVOC mass transfer with particle suspensions

Semi-volatile organic compounds (SVOC) exist in indoor air at very low concentrations (usually less than 100 µg/m3), but do great harm to human health. SVOC pollutants transfer in indoor air with suspended particles so complicatedly that traditional experimental methods are hardly to reveal the mass-transfer mechanism. This study employs Lattice Boltzmann method (LBM) to investigate the mass transfer behaviours of two-phase SVOC pollutants (gas- and particle-phase), and compare two widely-used gas/particle partition models (the instantaneous equilibrium model and the dynamic model). LBM is used to simulate the fluid flows and SVOC mass transfer, and the cell automation (CA) probabilistic model is applied to simulate the particle transport. The interaction between the gas- and particle-phase of SVOC is considered in the source term of the Lattice Boltzmann equations. One particle is firstly simulated in order to focus on the particle-phase concentration, then a large number of particles are simulated to focus on the effect of particles on the concentration field of SVOC. The simulation results show: (i) particles in the instantaneous equilibrium model for gas/particle partition always help gas-phase SVOC transport in indoor air by particle-mediation effect, while such an effect in the dynamic model is greatly determined by Kp and residence time of particles; (ii) particle-mediation effect can also increase the emission rate, and a non-uniform distribution of particles predicted by our numerical model indicates that such an additional emission rate increases exponentially with particle concentration, because a small number of particles have little possibility of approaching emission surface. (iii) Our numerical model can effectively estimate SVOC concentration in the presence of airborne particles by tracking each particle. These results highlight the roles of airborne particles in the transport of indoor SVOC pollutants, and are expected to be useful to consider dust deposition and resuspension when particles are in a realistic size distribution.

Characterization of road dust and resuspended particles close to a busy road of Venice mainland (Italy)

Road traffic contributes to atmospheric particulate matter with exhaust (fuel combustion) and non-exhaust (wear of vehicle parts such as brake, tires and abrasion of the road surface) emissions. Road dust is composed of particles belonging to natural and anthropogenic sources related in large part to road traffic. To date, understanding the relative contribution of road dust resuspension and particles directly emitted by abrasion to particulate matter is still a matter of debate. In this work, road dust and resuspended particles samples are collected at different heights and with increasing sampling time near a busy road of Venice mainland. Elemental composition and morphology of particles were investigated with a combination of techniques: inductively coupled plasma optical emission spectroscopy (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), laser diffraction analysis and scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM–EDX). The differences between deposited and resuspended particles were highlighted and the main pollutant sources were identified to study the resuspension process related to the traffic flow. Resuspended particles were divided into six groups related to the presence of anti-ice material, to soil resuspension and to the road surface and vehicle parts wear. The contributions of clustered particles vary with the height from the road level. This study, the first one focusing on the road traffic particles resuspension in Veneto region, will provide topical information for the identification of this source in atmospheric particulate samples.

Experimental measurements of pressure, temperature and dust velocities in case of LOVA: Comparisons with a multiphase numerical model

The production of dust inside the nuclear fusion power plants is one of the safety issues of this technology. Dust is generated because of plasma-material interactions and subsequently it deposits in the bottom regions of the TOKAMAK. In case of a Loss Of Vacuum Accident (LOVA), the dust may be resuspended, threatening the functioning and the safety of these reactors. A deep study of this phenomenon is required to develop countermeasures and to improve the safety of this promising way to produce energy. The authors have studied the fluid dynamics of these accidents with a scaled experiment, called STARDUST-Upgrade. Optical techniques have been implemented to measure dust resuspension and diffusion properties, such as velocity vectors and resuspension rate. This work shows the results obtained with a new numerical model able to take into account also the dispersed phase (dust). The software uses the Euler-Euler approach, a Schiller-Naumann resistance model, and a k-ε turbulence model. The dust used is tungsten dust, that has been placed close to the inlet valve in both cases (numerical and experimental). The numerical results are analysed and compared with the experimental ones and the main agreements and differences are highlighted. The results show good accordance with the velocity vectors of dust, while the resuspension rate is overestimated in the numerical case because of the absence of adhesion and cohesion forces between dust particles and walls. This analysis is the starting point for the evolution and completion of a numerical model suitable for dust resuspension in case of LOVAs.

PM2.5 in a megacity of Asia (Karachi): Source apportionment and health effects

Karachi, Pakistan is one of the largest and most polluted metropolitan cities in south Asia. Air quality was assessed using 24-hr fine-particulate matter (PM2.5) samples collected from two sites, Korangi (industrial/residential) and Tibet Center (commercial/residential). Spatial and temporal characteristics and sources of pollution were evaluated from August 2008 through August 2009 using samples analyzed for PM2.5, black carbon (BC), trace elements, and water-soluble ions. Elemental enrichment factors (EFs) and a receptor model/positive matrix factorization (PMF), were used to delineate the anthropogenic and natural sources. The mean 24-hr PM2.5 was 101 ± 45.6 μg m−3 at Korangi and 76.5 ± 38.4 μg m−3 at Tibet Center. Every 24-hr sample analyzed from both sites exceeded the WHO 24-hr guideline value of 25 μg m−3. Average PM2.5 levels were higher during winter, suggesting increased combustion activity and decreased air dispersion. EFs suggest significant contributions of trace elements from anthropogenic activities. Air pollution levels were higher at the Korangi site than Tibet Center, highlighting major contributions from industrial activities near the site. From PMF analysis, five sources and their relative contributions were determined at Korangi and Tibet Center, respectively: 1) oil combustion (25% and 21%); 2) soil and urban dust resuspension (28% and 25%); 3) vehicular emissions (23% and 5%); 4) sea spray (13% and 26%); and 5) industrial emissions (11% and 23%). The evaluation of health risk associated with exposure to air pollution indicated some major air pollution concerns in Karachi, stressing the need for the formulation and implementation of strict laws on PM2.5 emission.

Urban vegetation and particle air pollution: Experimental campaigns in a traffic hotspot

This work presents the main results of two experimental campaigns carried out in summer and winter seasons in a complex pollution hotspot near a large park, El Retiro, in Madrid (Spain). These campaigns were aimed at understanding the microscale spatio-temporal variation of ambient concentration levels in areas with high pollution values to obtain data to validate models on the effect of urban trees on particulate matter concentrations.Two different measuring approaches have been used. The first one was static, with instruments continuously characterizing the meteorological variables and the particulate matter concentration outside and inside the park. During the summer campaign, the particulate matter concentration was clearly influenced by a Saharan dust outbreak during the period 23 June to 10 July 2016, when most of the particulate matter was in the fraction PM2.5-10. During the winter campaign, the mass concentrations were related to the meteorological conditions and the high atmospheric stability.The second approach was a dynamic case with mobile measurements by portable instruments. During the summer campaign, a DustTrak instrument was used to measure PM10 and PM2.5 in different transects close to and inside the park at different distances from the traffic lane. It was observed a decrease in the concentrations up to 25% at 20 m and 50% at 200 m. High PM10 values were linked to dust resuspension caused by recreational activities and to a Saharan dust outbreak. The highest PM values were measured at the Independencia square, an area with many bus stops and high traffic density. During the winter campaign, three microaethalometers were used for Black Carbon measurement. Both pollutants also showed a reduction in their concentrations when moving towards inside the park. For PM10 and PM2.5, reductions up to 50% were observed, while for BC this reduction was smaller, about 20%.

Air quality, emissions, and source contributions analysis for the Greater Bengaluru region of India

Bengaluru - capital of the state of Karnataka is the original “Silicon Valley” of India. In this paper, we present a comprehensive snapshot of the state of air quality in Bengaluru, along with an emissions inventory for the pollutants necessary for chemical transport modeling at 0.01° grid resolution (approximately 1-km), for an urban airshed covering 60 × 60 grids (4300 km2). For 2015, emission estimates for the city are 31,300 tons of PM2.5, 67,100 tons of PM10, 5300 tons of SO2, 56,900 tons of NOx, 335,550 tons of CO, and 83,500 tons of NMVOCs. Overall, transport is the key emission source for Bengaluru - vehicle exhaust and on-road dust resuspension account for a combined 56% and 70% of total PM2.5 and PM10 emissions; followed by industries (17.8% including the brick kilns), open waste burning (11.0%), and domestic cooking, heating, and lighting (6.5%), in case of PM2.5. We conducted particulate pollution source apportionment of local and non-local sources, using WRF meteorological model and CAMx chemical transport modeling system. A comparison of range of 24-hr average modeled PM2.5 concentrations (36.5 ± 9.0 μg/m3) and monitored PM2.5 concentrations (32.3 ± 24.2 μg/m3) by month, shows that the model catches the quantitative ranges and qualitative trends. The modeled source contributions highlight the vehicle exhaust (28%) and dust (including on-road resuspended dust and construction activities) (23%), and open waste burning (14%), as the key air pollution sources. Unless there is an aggressive strategy to improve urban planning and public transport options, pollutant emissions under the business as usual scenario are expected to increase at least 50% in 2030 and doubling the urban area with PM2.5 annual averages above the national ambient standard of 40 μg/m3.

Element analysis and bioaccessibility assessment of ultrafine airborne particulate matter (PM0.1) using simulated lung fluid extraction (artificial lysosomal fluid and Gamble's solution)

Abstract Chemical characterization and source and bioaccessibility investigations were performed on airborne ultrafine particles (UFPs) collected from a trafficked road (Elgeseter) and a city background site (Torget) within the city of Trondheim, Norway from January 2014 to May 2015. Particles were collected using cascade impactors, and HNO3 soluble element concentrations were determined using high-resolution inductively-coupled plasma mass spectrometry (HR-ICP-MS). Element bioaccessibility was assessed by extraction in simulated lung fluids, and possible sources were investigated using enrichment factor (EF) and principal component analysis (PCA). UFP concentrations in air were somewhat higher at the roadside than at the city background site. Levels of total UFP and elemental components were variable, but overall low at both sites during the collection period. Concentrations of the typical crustal associated elements Al, Th, and Sc were highest in spring and summer at Elgeseter, indicating considerable contribution from re-suspension of road dust with mixed origin to atmospheric levels. W, known to be associated with studded tire wear, was highest in spring. Source identification analysis using enrichment factors and PCA indicated direct vehicular emissions, and re-suspension of road dust largely consisting of crustal-derived materials, as the two predominant sources of UFPs. Elements clearly associated with vehicular traffic emissions included Sb, Zn, Pb, As, and Cu. Several elements seemed to originate from both vehicle emissions and crustal material. To our knowledge no previous studies have investigated the bioaccessibility of metals in UFPs using extraction in simulated lung fluids. Our study indicated that solubility and thereby bioaccessibility is considerable for several potentially toxic elements found in UFPs, which may reach the inner lungs after inhalation. Solubility was overall highest for the elements Rb, Ni, As, Sn, Tl, and Cs. Extraction in the more acidic artificial lysosomal fluid (ALF) resulted in considerably higher element solubility compared to the neutral Gamble's solution.