| 1. |
- Ahrens, Lutz
(författare)
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Concentrations in air of organobromine, organochlorine and organophosphate flame retardants in Toronto, Canada
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 99, s. 140-147
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Tidskriftsartikel (refereegranskat)abstract
- Concentrations of organobromine (BFRs), organochlorine (CFRs) and organophosphate esters flame retardants and plasticizers (PFRs) in air were monitored for over one year at an urban site in Toronto, Canada during 2010-2011. The mean value for polybrominated diphenyl ethers (BDEs) (gas + particle phase) was 38 pg/m(3) with BDE-47 and BDE-99 as the dominant congeners. The mean concentrations in air for Sigma non-BDE (BFRs and CFRs), was 9.6 pg/m(3) about four times lower than the BDEs. The brominated FRs: TBP-AE, BTBPE, EH-TBB, BEH-TEBP and the chlorinated syn- and anti-DP were detected frequently, ranging from 87% to 96%. Highest concentrations in air among all flame retardant classes were observed for the Sigma-PFRs. The yearly mean concentration in air for EPFRs was 2643 pg/m(3) with detection frequency higher than 80%. Except for TBP-AE and b- DBE-DBCH, non-BDEs (BFRs, CFRs and PFRs) were mainly associated with the particle phase. BDE concentrations in air were positively correlated with temperature indicating that volatilization from local sources was an important factor controlling levels in air. This correlation did not hold for most BFRs, CFRs and PFRs which were mainly on particles. For these compounds, air concentrations in Toronto are likely related to emissions from point sources and advective inputs. This study highlights the importance of urban air monitoring for FRs. Urban air can be considered a sentinel for detecting changes in the use and application of FRs in commercial products. Crown Copyright (C) 2014 Published by Elsevier Ltd. All rights reserved.
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| 2. |
- Budhavant, K. B., et al.
(författare)
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Chemical composition of the inorganic fraction of cloud-water at a high altitude site in West India
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 88, s. 59-65
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Tidskriftsartikel (refereegranskat)abstract
- Data from a ground-based cloud-water collection system intercepting water from clouds at a mountain field station, Sinhagad near Pune in India are presented. This study was part of an Indo-Swedish Collaboration Project on Atmospheric Brown Cloud-Asia (ABC-A). Cloud-water and rainwater (wet-only) samples were collected during June 2007-Dec. 2010. Concentrations of major anions and cations were determined. Ion concentrations were generally higher (NO3-, about 8 times; SO42- and K+, 5 times; NH4+ times and Cl-, Na+, Ca2+, Mg2+ 3 times) in cloud-water samples than in rainwater samples collected during the same days. The average pH of cloud-water samples was 6.0 with about 20% of the values below 5.6 and only 4% less than 5.0. Despite high concentrations of SO42- and NO3- the cloud water samples were on average not more acidic than rainwater samples. This is different from most of the other studies of cloud-water composition which have noted a substantially higher acidity (i.e. lower pH) in cloud-water than in rainwater. The slightly alkaline (pH > 5.6) nature of the cloud-water samples is mainly due to the presence of soil derived calcium carbonate in quantities more than enough to neutralize the acids or their precursors. A separation of the cloud-water data into trajectory groups showed that samples in air-masses having spent the last few days over the Indian sub-continent were in general more acidic (due to anthropogenic emissions) than those collected during days with air-masses of marine origin. A high correlation mutually between Ca2+, Na+, NO3- and SO42- makes it difficult to estimate the contribution to SO42- from different sources. Anthropogenic SO2- emissions and soil dust may both give important contributions.
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| 3. |
- Degrendele, Céline, et al.
(författare)
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Size specific distribution of the atmospheric particulate PCDD/Fs, dl-PCBs and PAHs on a seasonal scale : Implications for cancer risks from inhalation
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier. - 1352-2310 .- 1873-2844. ; 98, s. 410-416
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Tidskriftsartikel (refereegranskat)abstract
- This study presents the seasonal size distribution of particulate polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in the atmosphere. Particles were sampled from October 2009 to October 2010 on a seasonal basis using a cascade impactor collecting six size fractions at a rural and urban site in the Brno area, Czech Republic. Higher concentrations of PAHs, PCDD/Fs and dl-PCBs were observed in cold seasons at both sites, attributed to the seasonality of the gas-particle partitioning, the increase of emissions and the lower boundary mixing layer in winter. All of the compounds showed a strong accumulation in the fine fraction, with, on average, 71% of Sigma PAHs, 73% of Sigma PCDD/Fs and 60% of Sigma dl-PCBs associated with particles <0.95 mu m. The human risk assessment via inhalation was addressed and followed the same pattern as for concentrations, with 41 and 7 times higher risk in winter compared to summer at the rural and urban sites, respectively. More than 70% of cancer risks of PAHs, PCDD/Fs and dl-PCBs was associated with particles <0.95 mu m. Moreover, an overestimation of the cancer risk via inhalation of up to 50% occurred when the size distribution of related compounds was not considered.
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| 4. |
- Fridell, Erik, et al.
(författare)
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A modelling study of the impact on air quality and health due to theemissions from E85 and petrol fuelled cars in Sweden
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier. - 1352-2310 .- 1873-2844. ; 82, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Alternative fuels are becoming more and more important for road traffic and one fuel that has been usedfor several years is ethanol (E85). The main discussion points regarding the environmental performancefor ethanol as a fuel are related to the production. However, there are also some notable differences inthe emissions between E85 and petrol fuelled vehicles. This relates to some extent to the emissions ofnitrogen oxides (NOx) and particulate matter (PM) but mainly to the composition of the emitted organiccompounds. In the present study two fuel scenarios for passenger cars are investigated for the VästraGötaland Region in Sweden; one where the cars with Otto engines run on petrol and one where they runon E85. Two emission scenarios for 2020 are constructed for the whole Europe and coupled dispersionchemistrymodelling is applied to obtain the population exposure to key pollutants. The differencesobtained from the modelling show decreased levels of NOx, ozone and benzene with E85 and increasedlevels of acetaldehyde in the Västra Götaland Region. For the latter the increase may be up to 80%, whileNOx and ozone show decreases of up to a few per cent and a few tenths of per cent, respectively.Exposure to the different air pollutants is calculated as population-weighted concentrations. The healthrisk assessment, using the calculated exposure and published exposureeresponse functions for therelevant pollutants, shows decreased health risks in the E85 scenario relative the all-petrol scenario, dueto the decreased NOx exposure, correlated with both preterm deaths and asthma. However, NOx (andNO2) may partly be indicators of unmeasured causal exhaust components in the epidemiological studiesand thus the exposureeresponse functions for these may not be applicable in the present case wherethere is a difference in NOx exposure but not a proportional difference in exposure to other exhaustcomponents normally associated with NOx. Smaller effects are expected from the changes in ozone,acetaldehyde, PM2.5 and benzene exposure. The overall difference is about 1.6 preterm deaths per yearfor the Västra Götaland Region, with lower values for the E85 scenario, when the uncertain differencesdue to the differences in NOx exposure are not considered.
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| 5. |
- Hagerman, Inger, et al.
(författare)
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Effects on heart rate variability by artificially generated indoor nano-sized particles in a chamber study
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 88, s. 165-171
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Tidskriftsartikel (refereegranskat)abstract
- Background: Airborne particles are associated with increased morbidity and mortality due to respiratory and cardiovascular diseases in polluted areas. There is a growing interest in nano-sized particles with diameter < 100 nm and their potential health effects. Heart rate variability (HRV) is a noninvasive method for cardiovascular risk prediction in high prevalent groups. Aim of study: The aim was to evaluate the impact of nano-sized indoor air particles on HRV for healthy and adult females. Methods: All exposures were performed as controlled chamber experiments with particle exposure from burning candles, terpene + ozone reactions or filtered air in a double-blind cross over design. Twenty-two healthy females were investigated during 10 min periods at different exposures and the reactivity in high frequency (HF) spectral band of HRV were computed. Results: Heart rate was unchanged from baseline values in all groups during all experimental settings. HF power of HRV tended to increase during exposure to particles from burning candle while particles from terpene + ozone reactions tended to decrease HF power. Conclusions: Exposure to nano-sized particles of burning candles or terpene + ozone reactions results in different patterns of heart rate variability, with signs of altered autonomic cardiovascular control. Practical implications: This study indicates that the HRV method may be used for information on physiological responses of exposure to different nano-sized particles and contribute to the understanding of mechanisms behind health effects of particle exposures. (C) 2014 The Authors. Published by Elsevier Ltd.
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| 6. |
- Malmqvist, Ebba, et al.
(författare)
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Assessing ozone exposure for epidemiological studies in Malmo and Umea, Sweden
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 94, s. 241-248
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Tidskriftsartikel (refereegranskat)abstract
- Ground level ozone [ozone] is considered a harmful air pollutant but there is a knowledge gap regarding its long term health effects. The main aim of this study is to develop local Land Use Regression [LUR] models that can be used to study long term health effects of ozone. The specific aim is to develop spatial LUR models for two Swedish cities, Umea and Malmo, as well as a temporal model for Malmo in order to assess ozone exposure for long term epidemiological studies. For the spatial model we measured ozone, using Ogawa passive samplers, as weekly averages at 40 sites in each study area, during three seasons. This data was then inserted in the LUR-model with data on traffic, land use, population density and altitude to develop explanatory models of ozone variation. To develop the temporal model for Malmo, hourly ozone data was aggregated into daily means for two measurement stations in Malmo and one in a rural area outside Malmo. Using regression analyses we inserted meteorological variables into different temporal models and the one that performed best for all three stations was chosen. For Malmo the LUR-model had an adjusted model R-2 of 0.40 and cross validation R-2 of 0.17. For Umea the model had an adjusted model R-2 of 0.67 and cross validation adjusted R-2 of 0.48. When restricting the model to only including measuring sites from urban areas, the Malmo model had adjusted model R-2 of 0.51 (cross validation adjusted R-2 0.33) and the Umea model had adjusted model R-2 of 0.81 (validation adjusted R-2 of 0.73). The temporal model had adjusted model R-2 0.54 and 0.61 for the two Malmo sites, the cross validation adjusted R-2 was 0.42. In conclusion, we can with moderate accuracy, at least for Umea, predict the spatial variability, and in Malmo the temporal variability in ozone variation. (C) 2014 The Authors. Published by Elsevier Ltd.
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| 7. |
- Tang, L., et al.
(författare)
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Estimation of the long-range transport contribution from secondary inorganic components to urban background PM10 concentrations in south-western Sweden during 1986-2010
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 89, s. 93-101
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Tidskriftsartikel (refereegranskat)abstract
- The contribution of long-range transported (LRT) to urban background PM10 concentrations was investigated from a long-term view from 1986 to 2010. Regional air concentrations of sulphate (SO42-), nitrate (NO3-), and ammonium (NH4+) were used as a sum (C-ion) to investigate the contribution from these ions to the LRT PM10 concentrations at an urban background site in Gothenburg, Sweden. Utilizing backwards trajectory analysis, the LRT contribution from C-ion to the urban background PM10 concentrations (LRTCion) was estimated for six unique transport pathways and related source areas. Air masses transported over eastern Europe, UK/North Sea/Denmark and the vicinity of Scandinavia were associated with high C-ion concentrations observed in Gothenburg. For each pathway, multiple linear models based on the C-ion concentrations were used to estimate LRTCion and PM10 at the urban background site. The performances of the multiple linear models were satisfying with R-2 between estimated and observed annual mean PM10 concentrations of 0.81 during the monitoring years 1990-2010. The models were able to describe the main features of the day-to-day average PM10 concentrations, but underestimated high level values. The annual estimated LRTCion contribution decreased from 7 +/- 2 mu g/m(3) for 1986-2000 to 5 +/- 1 mu g/m(3) for 2001-2010. The higher LRTCion contribution was related to the transport cluster from eastern Europe, UK/North Sea/Denmark and the vicinity of South Scandinavia. (C) 2014 Elsevier Ltd. All rights reserved.
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| 8. |
- Westerlund, J., et al.
(författare)
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Application of air quality combination forecasting to Bogota
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 89, s. 22-28
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Tidskriftsartikel (refereegranskat)abstract
- The bulk of existing work on the statistical forecasting of air quality is based on either neural networks or linear regressions, which are both subject to important drawbacks. In particular, while neural networks are complicated and prone to in-sample overfitting, linear regressions are highly dependent on the specification of the regression function. The present paper shows how combining linear regression forecasts can be used to circumvent all of these problems. The usefulness of the proposed combination approach is verified using both Monte Carlo simulation and an extensive application to air quality in Bogota, one of the largest and most polluted cities in Latin America. (C) 2014 Elsevier Ltd. All rights reserved.
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| 9. |
- Wierzbicka, Aneta, et al.
(författare)
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Detailed diesel exhaust characteristics including particle surface area and lung deposited dose for better understanding of health effects in human chamber exposure studies
- 2014
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 86, s. 212-219
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Tidskriftsartikel (refereegranskat)abstract
- Several diesel exhaust (DE) characteristics, comprising both particle and gas phase, recognized as important when linking with health effects, are not reported in human chamber exposure studies. In order to understand effects of DE on humans there is a need for better characterization of DE when performing exposure studies. The aim of this study was to determine and quantify detailed DE characteristics during human chamber exposure. Additionally to compare to reported DE properties in conducted human exposures. A wide battery of particle and gas phase measurement techniques have been used to provide detailed DE characteristics including the DE particles (DEP) surface area, fraction and dose deposited in the lungs, chemical composition of both particle and gas phase such as NO, NO2, CO, CO2, volatile organic compounds (including aldehydes, benzene, toluene) and polycyclic aromatic hydrocarbons (PAHs). Eyes, nose and throat irritation effects were determined. Exposure conditions with PM1 (<1 mu m) mass concentration 280 mu g m(-3), number concentration 4 x 10(5) cm(-3) and elemental to total carbon fraction of 82% were generated from a diesel vehicle at idling. When estimating the lung deposited dose it was found that using the size dependent effective density (in contrast to assuming unity density) reduced the estimated respiratory dose by 132% by mass. Accounting for agglomerated structure of DEP prevented underestimation of lung deposited dose by surface area by 37% in comparison to assuming spherical particles. Comparison of DE characteristics reported in conducted chamber exposures showed that DE properties vary to a great extent under the same DEP mass concentration and engine load. This highlights the need for detailed and standardized approach for measuring and reporting of DE properties. Eyes irritation effects, most probably caused by aldehydes in the gas phase, as well as nose irritation were observed at exposure levels below current occupational exposure limit values given for exhaust fumes. Reporting detailed DE characteristics that include DEP properties (such as mass and number concentration, size resolved information, surface area, chemical composition, lung deposited dose by number, mass and surface) and detailed gas phase including components known for their carcinogenic and irritation effect (e.g. aldehydes, benzene, PAHs) can help in determination of key parameters responsible for observed health effects and comparison of chamber exposure studies. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.
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