| 1. |
- Aas, Wenche, et al.
(författare)
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Trends in Air Pollution in Europe, 2000–2019
- 2024
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Ingår i: Aerosol and Air Quality Research. - 2071-1409 .- 1680-8584. ; 24:4
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Tidskriftsartikel (refereegranskat)abstract
- This paper encompasses an assessment of air pollution trends in rural environments in Europe over the 2000–2019 period, benefiting from extensive long-term observational data from the EMEP monitoring network and EMEP MSC-W model computations. The trends in pollutant concentrations align with the decreasing emission patterns observed throughout Europe. Annual average concentrations of sulfur dioxide, particulate sulfate, and sulfur wet deposition have shown consistent declines of 3–4% annually since 2000. Similarly, oxidized nitrogen species have markedly decreased across Europe, with an annual reduction of 1.5–2% in nitrogen dioxide concentrations, total nitrate in the air, and oxidized nitrogen deposition. Notably, emission reductions and model predictions appear to slightly surpass the observed declines in sulfur and oxidized nitrogen, indicating a potential overestimation of reported emission reductions. Ammonia emissions have decreased less compared to other pollutants since 2000. Significant reductions in particulate ammonium have however, been achieved due to the impact of reductions in SOx and NOx emissions. For ground level ozone, both the observed and modelled peak levels in summer show declining trends, although the observed decline is smaller than modelled. There have been substantial annual reductions of 1.8% and 2.4% in the concentrations of PM10 and PM2.5, respectively. Elemental carbon has seen a reduction of approximately 4.5% per year since 2000. A similar reduction for organic carbon is only seen in winter when primary anthropogenic sources dominate. The observed improvements in European air quality emphasize the importance of comprehensive legislations to mitigate emissions.
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| 2. |
- Abbasi, Saeed, 1973-, et al.
(författare)
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Technical note: Experiences of studying airborne wear particles from road and rail transport
- 2013
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Ingår i: Aerosol and Air Quality Research. - : Taiwan Association for Aerosol Research. - 1680-8584 .- 2071-1409. ; 13:4, s. 1161-1169
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Tidskriftsartikel (refereegranskat)abstract
- Airborne particles and their adverse effects on air quality have been recognized by humans since ancient times. Current exhaust emission legislations increase the relative contribution of wear particles on the PM levels. Consequently, wearbased particle emissions from rail and road transport have raised concerns as ground transportation is developing quickly. Although scientific research on airborne wear-based particles started in 1909, there is almost no legislation that control the generation of wear-based particles. In addition, there is no accepted and approved standard measurement technique for monitoring and recording particle characteristics. The main objective of this study is to review recent experimental work in this field and to discuss their set-ups, the sampling methods, the results, and their limitations, and to propose measures for reducing these limitations.
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| 3. |
- Cha, Yingying, 1989-, et al.
(författare)
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Variation in Airborne Particulate Levels at a Newly Opened Underground Railway Station
- 2019
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Ingår i: Aerosol and Air Quality Research. - : TAIWAN ASSOC AEROSOL RES-TAAR. - 1680-8584 .- 2071-1409. ; 19:4, s. 737-748
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Tidskriftsartikel (refereegranskat)abstract
- The construction of a new railway tunnel for commuter trains in Stockholm was completed in 2017. It included two modern stations (Odenplan and Stockholm City) with platform screen doors (PSD) and one old station (Stockholm Sodra) without PSDs. This study evaluates the concentrations of airborne particulates at the new Odenplan station, focusing on the effects of traffic operation, system age and train movement. For comparison, the other two stations in the tunnel and an above-ground railway station (Solna) were also investigated. The new platform was clean prior to opening for traffic (the average concentration of PM10 and PM2.5 was 12 and 2 mu g m(-3), respectively). Substantial increases in the PM10 and PM2.5 levels were observed after it came into service, with the average concentrations increasing to 120 and 30 mu g m(-3) after 1 week and then to 175 and 35 mu g m(-3) after 3 months of operation. The train movement factor (traffic frequency and train stopping period) was found to have a strong effect on the coarse-sized particle concentrations (0.3-10 mu m). Comparable levels of PM10 and PM2.5 were measured at both the new Odenplan station and the old station, where the amount of traffic was similar. For the other new station, Stockholm City, where traffic was only half as frequent, the PM10 and PM2.5 levels were substantially lower.
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| 4. |
- Cha, Yingying, 1989-, et al.
(författare)
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Variation of airborne particulate levels in a newly built railway tunnel
- 2018
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Ingår i: Aerosol and Air Quality Research. - 1680-8584 .- 2071-1409.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The construction of a new railway tunnel for commuter trains in Stockholm was completed in 2017. It included two modern stations (Odenplan and Stockholm City) with platform screen doors (PSD) and one old station (Stockholm Södra) without PSDs. This study evaluates the concentrations of airborne particulates for the new stations, focussing on the effects of traffic operation, system age and train movement. For comparison, the other old station in the tunnel and an above-ground railway station (Solna) were also investigated. The new Odenplan platform was clean before its opening for traffic (12 and 2 μg/m3 for average PM10 and PM2.5, respectively). Substantial increases in the PM10 and PM2.5 concentrations were observed after it came into service. The average levels of PM10 and PM2.5 increased to 120 and 30 μg/m3 after one week of operation, and increased again to 175 and 35 μg/m3 after 3 months. The train movement factor (traffic frequency and train stop period) was found to have a strong effect on the particle concentrations of coarse sizes (0.3–10 μm). Comparable levels of PM10 and PM2.5 were measured at both the new station and the old station where the traffic frequency was similar. For the other new station, which had half the traffic frequency due to the station design with two separate platforms, the PM10 and PM2.5 levels were substantially lower.
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| 5. |
- Chen, Jing, et al.
(författare)
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Impact of relative humidity and water soluble constituents of PM2.5 on visibility impairment in Beijing, China
- 2014
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Ingår i: Aerosol and Air Quality Research. - : Taiwan Association for Aerosol Research. - 1680-8584 .- 2071-1409. ; 14:1, s. 260-268
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Tidskriftsartikel (refereegranskat)abstract
- Beijing has been experiencing severe particulate pollution accompanying the fast growing population and economy. This study investigated the impact of PM2.5 and its water soluble organic and inorganic constituents on visual impairment in Beijing under different meteorological conditions. According to the analysis of PM2.5 samples collected in Spring 2012, water soluble species took up 38.1% of PM2.5 mass, among which NO3– was the most abundant constituent, followed by SO42–, NH4+ and water soluble organic matter. The correlation analysis between visibility and aerosol loadings as well as meteorological parameters revealed the dominant impact of meteorological conditions, relative humidity in particular, on visibility impairment over the mass concentration of PM2.5. Compared to the total aerosol loading of PM2.5, visibility was better correlated with the total mass of water soluble constituents (WSC). The visual range in Beijing was the most sensitive to both WSC and PM2.5 in the RH range of 30–70%. Severe visual impairment was observed for RH ≥ 70% with the least sensitivity to WSC and PM2.5. The effects of synoptic scale circulation on meteorological variables that affect air quality were also examined with the movement of a cold front as a case study. The findings have direct implications to region-wide policy-making and control strategies.
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| 6. |
- Dobric, Julia, et al.
(författare)
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Preschool Children’s Inhalation Rates Estimated from Accelerometers—A Tool to Estimate Children’s Exposure to Air Pollution
- 2022
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Ingår i: Aerosol and Air Quality Research. - : AAGR Aerosol and Air Quality Research. - 1680-8584 .- 2071-1409. ; 22:8
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Tidskriftsartikel (refereegranskat)abstract
- Children are particularly sensitive to air pollution exposure, and their personal exposures may differ significantly from those of adults. One key factor for understanding the personal inhaled dose of air pollutants is the respiratory minute ventilation (Ve). To estimate the amount of particles circulated through the lungs, 24 h averages of Ve are often used. These averages poorly capture variations in Ve during the day, and between individuals. We here develop and implement a concept to assess individual Ve of children, with minimal impact on their natural activity and movement pattern by using ActiGraph GT3X+ accelerometers. Activity of 136 preschool children in the ages 3 to 5 years was logged using accelerometers while the children attended their preschools during a week. A linear regression equation is developed and used for estimating Ve from the accelerometer data retrieved for each individual child. The results show large variations in weekly average Ve between individuals, ranging from 0.33 to 0.48 L min–1 kg–1. Over the days the averages of the individuals’ 1st and 3rd quartiles were 0.28 and 0.48 L min–1 kg–1, respectively. Outdoor activities resulted in a 17% higher Ve than indoor activities, which may be important to consider when estimating the inhaled dose of air pollutants since pollution levels and particle toxicities can be different indoors and outdoors. The observations motivate the use of individual values of Ve in exposure assessments and suggest that accelerometers are a suitable tool for estimating children’s individual Ve in their natural environment. Combined with time resolved local air pollution monitoring, these measurements can provide the basis of a more precise estimate of children’s inhaled dose of air pollutants. © The Author(s).
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| 7. |
- Gaita, Samuel Mwaniki, 1976, et al.
(författare)
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Characterization of Size-Fractionated Particulate Matter and Deposition Fractions in Human Respiratory System in a Typical African City: Nairobi, Kenya
- 2016
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Ingår i: Aerosol and Air Quality Research. - : Taiwan Association for Aerosol Research. - 2071-1409 .- 1680-8584. ; 16:10, s. 2378-2385
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Tidskriftsartikel (refereegranskat)abstract
- Information from elemental and mass composition of size-fractionated airborne particle matter (PM) provides insightfulknowledge about their impact on human health, meteorology and climate. To attain insight into the nature of sizefractionatedPM from a typical African city, samples were collected from an urban background site in Nairobi, Kenya,during the months of August and September in 2007. PM samples ranging in size from 0.06 to 16 µm aerodynamicdiameter were collected on pre-weighed polycarbonate filters with 0.4 µm pore size using a nine-stage cascade impactor.Particles less than 0.06 µm were collected on a backup filter. A total of 170 samples were collected and analysed for traceelements using the Proton Induced X-Ray Emission (PIXE) technique. The analysis showed that Si, Fe and S dominated inall size ranges and displayed unimodal mass-size distribution whereas K, Cu, Zn and Pb, depicted bimodal mass-sizedistribution highlighting the multiplicity of their sources. To estimate human exposure to PM, deposition fractions of boththe coarse and fine PM in the human respiratory system were calculated. The deposited concentration was found to behighest in the head airways region compared to the tracheobronchial and pulmonary regions.
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| 8. |
- Imani Jajarmi, Ramin, 1987-, et al.
(författare)
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The Influence of Air Flow Velocity and Particle Size on the Collection Efficiency of Passive Electrostatic Aerosol Samplers
- 2019
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Ingår i: Aerosol and Air Quality Research. - : Taiwan Association for Aerosol Research. - 1680-8584 .- 2071-1409. ; 19:2, s. 192-203
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Tidskriftsartikel (refereegranskat)abstract
- Electrostatic sampling is a promising method for the collection of bioaerosol particles. Although the underlying physics responsible for particle collection are well understood, the collection efficiency of simple passive electrostatic samplers is difficult to predict. Under these conditions, the collection efficiency becomes very sensitive to ambient air current and particle size, especially for submicron particles relevant for airborne virus transmission. In this paper, we compare two electrostatic aerosol sampler designs, a commercial product consisting of a flat collector plate located in the same plane as the charging needles and an axisymmetric design sampling directly to a liquid droplet. The aerosol particle collection efficiency of the samplers is investigated for particle size ranging from 0.25 to 2 µm while the air flow velocity surrounding the samplers is varied from 0.3 to 1 m s–1. For the planar design, at all ambient flow velocities, the submicron fraction of the particles captured originates in streamlines up to a maximum of 75 mm above the surface of the device collector, which greatly limits the volume of air being effectively sampled. The axisymmetric design features a non-monotonic capture efficiency as a function of particle size, with a minimum between 0.4 and 0.8 µm. The flow field in the inter-electrode region, captured using particle image velocimetry (PIV) reveals the presence of strong recirculation zones that can be responsible for the increased collection efficiency for very small particles.
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| 9. |
- Isa, Khairul Nizam Mohd, et al.
(författare)
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The Impact of Exposure to Indoor Pollutants on Allergy and Lung Inflammation among School Children in Selangor, Malaysia : An Evaluation Using Factor Analysis
- 2020
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Ingår i: Aerosol and Air Quality Research. - : Taiwan Association for Aerosol Research. - 1680-8584 .- 2071-1409. ; 20:11, s. 2371-2383
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Tidskriftsartikel (refereegranskat)abstract
- A cross-sectional study of 470, 14-year-old students from 8 secondary schools located in sub-urban and urban areas in Hulu Langat district, Selangor, Malaysia was undertaken to determine the impact of atmospheric indoor air pollutants on atopy, asthma, respiratory symptoms and lung inflammation among school children. The students were surveyed using ISAAC and ECRHS questionnaires, their FeNO levels were measured and allergic skin prick tests were conducted. Active and passive sampling was used to measure the classroom indoor air concentration of NO2, CO2, formaldehyde, PM10, PM2.5, temperature and relative humidity. Linear mixed model, two-levels multiple logistic regression, PCA and SPC were applied to determine the complex relationship between respiratory symptoms, personal factors, FeNO levels and atmospheric indoor pollutants. 20.6% of students reported daytime breathlessness and 55.5% reported having rhinitis in the last 12 months. Atopy was prevalent in 57.7% of students, with predominant sensitization to Derp1 (51.9%) and Derf1 (47.9%) among doctor's diagnosed asthmatic students. Indoor air pollutants in urban area schools were significantly higher than those in sub-urban areas (p < 0.001). There was a significant association between exposure to PM10 (OR = 2.66, 95% CI: 1.33-5.30) with skin allergy symptoms in the past 12 months. The PCA suggested that the most prominent factor associated with increasing FeNO levels was PM10, with 73.5% of the variation. SPC predicted the pattern of FeNO at an upper confidence limit (UCL) of 104.21 ppb with increasing PM10 concentration in the classroom (UCL = 40.23 mu g m(-3)). Exposure to PM10 and PM2.5 significantly influenced the inflammation of the school children's lungs. Moreover, there were associations between self-reported wheezing, daytime and nocturnal attack of breathlessness with doctor's diagnosed asthma among school children.
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| 10. |
- Krecl, Patricia, et al.
(författare)
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Characterisation and Source Apportionment of Submicron Particle Number Size Distributions in a Busy Street Canyon
- 2015
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Ingår i: Aerosol and Air Quality Research. - : Taiwan Association for Aerosol Research. - 1680-8584 .- 2071-1409. ; 15:1, s. 220-233
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Tidskriftsartikel (refereegranskat)abstract
- Street canyons are well-known hot spots due to the harmful exposure to high concentrations of atmospheric pollutants emitted mainly by motor vehicles. We report on measurements of air pollutants conducted in a street canyon in Stockholm (Sweden) in spring 2006. Particle number size distributions (PNSD) were measured in the 25-606 nm range, along with total particle number, light-absorbing carbon mass concentration (M-LAC), PM10, NOx, CO, traffic rate (TR), vehicle speed and meteorological variables. We used PNSD as input to the positive matrix factorisation (PMF) analysis to identify and apportion the pollutant sources. All pollutants showed distinct diurnal patterns, with highest concentrations in weekday mornings (08:00-09:00). TR was always higher on weekdays, except for the early hours (00:00-06:00). The raise in the weekend early-hour TR was accompanied by the largest MLAC of the day, a higher NOx/CO ratio compared to weekdays and a modal shift of PNSD towards larger diameters (47-56 nm), indicates a change in the vehicle fleet share to being dominated by diesel-run taxis. The largest contribution to the submicron particles was observed for winds blowing along the canyon, transporting particles emitted by vehicles accelerating from the traffic lights at the intersection, uphill towards the measurement site, and from the nearby streets. Three PMF factors were identified: local emissions from a mixed fleet dominated by gasoline engines, local traffic emissions highly impacted by diesel vehicles, and urban background aerosol. On average, gasoline-fuelled vehicles largely contributed to NOx, and particle number concentrations (54-65%), whereas M-LAC sources were dominated by diesel emissions, especially at weekends in the early hours (73%). The urban background contribution was rather low (4-13%) and with little dependence on the weekday. This work demonstrated how particle size distribution measurements, together with M-LAC, NOx and CO can be used to quantify the contribution from diesel and gasoline vehicles.
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