| 1. |
- Molnár, Peter, 1967, et al.
(författare)
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Domestic wood burning and PM2.5 trace elements: Personal exposures, indoor and outdoor levels
- 2005
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 39:14, s. 2643-2653
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Tidskriftsartikel (refereegranskat)abstract
- Personal exposures as well as indoor and outdoor levels of PM2.5 were measured with cyclones and impactors simultaneously in the winter of 2003 in a residential area where wood burning for domestic space heating is common. Twenty-four-hour samples from both wood-burning households ("wood burners") and a reference group were analysed for mass and elemental concentration using energy dispersive X-ray fluorescence (EDXRF) and for black smoke (BS) concentration using an EEL 43 reflectometer. Wood-smoke particles made statistically significant contributions of K, Ca, and Zn for both personal exposure and indoor concentration, the median levels of these elements being 66-80% higher for the wood-burning group. In addition, Cl, Mn, Cu, Rb, and Pb were found to be possible markers of wood smoke, though levels of these were only significantly higher among the wood-burning group for either personal exposure or indoor concentrations. PM2.5 mass and S levels were not significantly elevated in wood burners, probably due to large variations in outdoor concentrations from long-distance transported air pollution. Personal exposure and indoor levels showed high correlations for all species, and the personal exposure levels were usually higher than or equal to the indoor levels. The associations between personal exposure and outdoor levels were generally weak except for outdoor S and PM2.5 levels that were both highly correlated with personal S exposure levels (r(s) > 0.8). (c) 2005 Elsevier Ltd. All rights reserved.
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| 2. |
- Molnár, Peter, 1967, et al.
(författare)
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Residential NOx exposure in a 35-year cohort study. Changes of exposure, and comparison with back extrapolation for historical exposure assessment
- 2015
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 115, s. 62-69
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Tidskriftsartikel (refereegranskat)abstract
- In this study we aimed to investigate the effects on historical NOx estimates on time trends, spatial distributions, exposure contrasts, the effect of relocation patterns and the effects of back extrapolation. Historical levels of nitrogen oxides (NOx) from 1975 to 2009 were modeled with high resolution in Gothenburg, Sweden, using historical emission databases and Gaussian models. Yearly historical addresses were collected and geocoded from a population-based cohort of Swedish men from 1973 to 2007, with a total of 160,568 address years. Of these addresses, 146,675 (91%) were within our modeled area and assigned a NOx level. NOx levels decreased substantially from a maximum median level of 43.9μg/m3 in 1983 to 16.6μg/m3 in 2007, mainly due to lower emissions per vehicle km. There was a considerable variability in concentrations within the cohort, with a ratio of 3.5 between the means in the highest and lowest quartile. About 50% of the participants changed residential address during the study, but the mean NOx exposure was not affected. About half of these moves resulted in a positive or negative change in NOx exposure of >10μg/m3, and thus changed the exposure substantially. Back extrapolation of NOx levels using the time trend of a background monitoring station worked well for 5-7 years back in time, but extrapolation more than ten years back in time resulted in substantial scattering compared to the "true" dispersion models for the corresponding years. These findings are important to take into account since accurate exposure estimates are essential in long term epidemiological studies of health effects of air pollution.
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| 3. |
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| 4. |
- Strandberg, Bo, 1960, et al.
(författare)
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Field evaluation of two diffusive samplers and two adsorbent media to determine 1,3-butadiene and benzene levels in air
- 2006
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Ingår i: Atmospheric Environment. - : Elsevier. - 1352-2310 .- 1873-2844. ; 40:40, s. 7686-7695
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Tidskriftsartikel (refereegranskat)abstract
- Two types of diffusive samplers, both of which are compatible with thermal desorption, but differ in their geometry-SKC-Ultra (badge-type) and Radiello (radial symmetry-type)-were evaluated indoors and outdoors under varying temperature, humidity and wind speed conditions, using the graphitized adsorbents Carbopack X or Carbograph 5 to measure 1,3-butadiene and benzene in ambient air. The results obtained by diffusive sampling were compared with results obtained using a conventional active sampling method over both long (1 week) and shorter periods (6-24 h). Analysis and detection were performed using an automatic thermal desorber (ATD) connected to a gas chromatograph-flame ionization detector (GC/FID). Results from each sampler and adsorbent combination were examined using ordinary or multiple linear regression analysis. The overall uncertainty (OU) was also determined. In general, the results obtained with both samplers showed good agreement with those obtained by active sampling. Carbopack X appeared to be a more efficient adsorbent than Carbograph 5 for 1,3-butadiene, but the two adsorbents were equivalent for benzene. No effects of either humidity or air velocity were observed. Minor temperature effects were observed for both samplers for 1,3-butadiene. In summary, the results confirmed the accuracy of sampling rates previously determined for the two samplers and adsorbents. We consider the two samplers to be suitable for stationary and personal monitoring for the general population of 1,3-butadiene and benzene in various environments, indoors and outdoors. They are almost independent of meteorological conditions and may be suitable for monitoring industrial atmospheres.
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| 5. |
- Wängberg, I, et al.
(författare)
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Emissions, dispersion and human exposure of mercury from a Swedish chlor-alkali plant
- 2005
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 39:39, s. 7451-7458
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Tidskriftsartikel (refereegranskat)abstract
- Mercury in air near a mercury cell chlor-alkali plant in Sweden has been measured within the EU-project EMECAP. Based on the measurements and modelling the annual distributions of GEM and RGM have been calculated for the local area around the plant. The average concentration of GEM in residential areas near the plant was found to be 1-3.5 ng m(-3) higher in comparison to the background concentration in this part of Sweden. The emission of RGM (0.55 kg year(-1)) results in elevated RGM concentrations close to the plant. The greatest impact on the local area is due to wet deposition of RGM. However, only a small fraction (0.4%) of all mercury being emitted was found to be deposited in the local area. No impact on urinary mercury could be demonstrated in the population living close to the plant. (c) 2005 Elsevier Ltd. All rights reserved.
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