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| 2. |
- Forsberg, Bertil, et al.
(författare)
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Air pollution and respiratory health of children : the PEACE panel study in Umea., Sweden.
- 1998
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Ingår i: European Respiratory Review. - 0905-9180 .- 1600-0617. ; 8:52, s. 12-19
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Tidskriftsartikel (refereegranskat)abstract
- The Pollution Effects on Asthmatic Children in Europe (PEACE) study examined the acute effects of short-term changes in air pollution on symptomatic children. We were one of 14 research centres in Europe that used a common study protocol. Seventy five children in an urban panel and 72 children in a control panel, selected with a screening questionnaire, were characterized with lung function tests and skin-prick tests and followed in a 12 week diary study. Identical air quality monitoring stations were set up in our two study areas. The levels and ranges in concentrations for all air pollution indices were small. A negative correlation was seen between time spent outdoors and pollution levels, which may have weakened the correlation between personal exposure and outdoor concentrations and obscured any effect of air pollution. No consistent pattern of relations between air pollution and adverse effects were found, but particulates and nitrogen dioxide tended to be associated with a nonsignificant increase in symptoms and medication use on the same day. No clear effect of air pollution on respiratory health could be demonstrated.
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| 4. |
- Nyren, O, et al.
(författare)
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Smoking and colorectal cancer: A 20-year follow-up study of Swedish construction workers
- 1996
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Ingår i: JOURNAL OF THE NATIONAL CANCER INSTITUTE. - : NATL CANCER INSTITUTE. - 0027-8874. ; 88:18, s. 1302-1307
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although cigarette smoking has consistently been shown to be positively related to the risk of adenomatous polyp development (benign neoplastic growth of epithelial tissue in the colon), most studies of cigarette smoking and the risk of colore
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| 8. |
- Sandstrom, T, et al.
(författare)
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Effects of repeated exposure to 4 ppm nitrogen dioxide on bronchoalveolar lymphocyte subsets and macrophages in healthy men
- 1992
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Ingår i: European Respiratory Journal. - 1399-3003. ; 5:9, s. 1092-1096
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Tidskriftsartikel (refereegranskat)abstract
- Following the basal descriptive studies of the bronchoalveolar inflammatory cell response induced by single exposure with nitrogen dioxide (NO2) in man, it was considered important to clarify the cell response to repeated exposure with NO2. This investigation was, therefore, undertaken with bronchoalveolar lavage (BAL) 3 weeks before and 24 h after six repeated exposures with 4 ppm NO2 (7 mg.m-3) in ten healthy volunteers. The exposures were performed during 20 min and every second day. Analysis of the recovered BAL fluid demonstrated that repeated exposures to NO2 caused a lung cell response different from that reported after a single exposure. Amounts of lavaged alveolar macrophages, B-cells, and natural killer (NK)-cells were decreased and the T-helper-inducer/cytotoxic-suppressor cell ratio was altered, but there was no lymphocytosis or mastocytosis as after single exposure. Lymphocyte numbers in peripheral blood were reduced after exposure. These results suggest that repeated exposure with NO2 adversely affects the immune defence. This could contribute to the increased susceptibility to airway infections reported to be associated with NO2 exposure.
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| 9. |
- Sandstrom, T, et al.
(författare)
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Inflammatory cell response in bronchoalveolar lavage fluid after nitrogen dioxide exposure of healthy subjects: a dose-response study
- 1991
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Ingår i: European Respiratory Journal. - 1399-3003. ; 4:3, s. 332-339
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Tidskriftsartikel (refereegranskat)abstract
- The combination of environmental chamber exposure and bronchoalveolar lavage (BAL) was used to study the effects of the common air pollutant nitrogen dioxide (NO2). Eighteen healthy nonsmokers were exposed to NO2 during 20 min in an exposure chamber during light bicycle ergometer work. All subjects were examined with BAL at least 3 wks before exposure, as a reference. The subjects were re-examined with BAL, in groups of eight, 24 h after exposure to 4, 7 and 10 mg NO2.m.3 (2.25, 4.0 and 5.5 ppm), respectively. An inflammatory cell response was found after exposure to all concentrations. An increase in the number of lymphocytes in BAL fluid was observed after 7 and 10 mg.m.3 (p less than 0.05 and 0.02, respectively). An increase in the number of mast cells, that appears to be dose-dependent, was found after exposure to all concentrations. The proportion of lysozyme positive alveolar macrophages was elevated after exposure to 7 mg.m.3. The inflammatory mediators fibronectin, hyaluronan, angiotensin converting enzyme (ACE) and beta 2-microglobulin were unchanged by exposure. Due to the findings of inflammatory cell changes far below the peak exposure limits for work places in industrialized countries, 9-18 mg.m.3, the safety of these limits is questioned. Studies are in progress in our laboratory using BAL to evaluate the effects of repeated NO2 exposure.
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| 10. |
- Stjernberg, Ann-Christine Engvall, et al.
(författare)
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Low concentrations of near-surface ozone in Siberia
- 2012
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Ingår i: Tellus. Series B, Chemical and physical meteorology. - : Stockholm University Press. - 0280-6509 .- 1600-0889. ; 64, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Siberia with its large area covered with boreal forests, wetlands and tundra is believed to be an important sink for ozone via dry deposition and reactions with biogenic volatile organic compounds (BVOCs) emitted by the forests. To study the importance of deposition of ozone in Siberia, we analyse measurements of ozone mixing ratios taken along the Trans-Siberian railway by train, air-borne measurements and point measurements at the Zotino station. For all data, we ran the Lagrangian particle dispersion model FLEXPART in backward mode for 20 d, which yields the so-called potential emission sensitivity (PES) fields. These fields give a quantitative measure of where and how strongly the sampled air masses have been in contact with the surface and hence possible influenced by surface fluxes. These fields are further statistically analysed to identify source and sink regions that are influencing the observed ozone. Results show that the source regions for the surface ozone in Siberia are located at lower latitudes: the regions around the Mediterranean Sea, the Middle East, Kazakhstan and China. Low ozone mixing ratios are associated to transport from North West Russia, the Arctic region, and the Pacific Ocean. By calculating PES values for both a passive tracer without consideration of removal processes and for an ozone-like tracer where dry deposition processes are included, we are able to quantify the ozone loss occurring en route to the receptor. Strong correlations between low ozone concentrations and the spatially integrated footprints from FLEXPART, especially during the period summer to autumn, indicate the importance of the Siberian forests as a sink for tropospheric ozone.
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