| 11. |
- 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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| 12. |
- van der Westhuizen, Deidré, et al.
(författare)
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Atmospheric fine particulate matter (PM2.5) in Bloemfontein, South Africa
- 2022
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Ingår i: International Journal of Environmental Analytical Chemistry. - : Informa UK Limited. - 0306-7319 .- 1029-0397.
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Tidskriftsartikel (refereegranskat)abstract
- Indoor and outdoor pollution has become a worldwide problem; it impacts both the environment and human health. Research-driven air pollution assessment studies were done in some of the larger South African cities like Cape Town and Pretoria, but almost none in the Free State province. The purpose of the present study was to determine PM2.5 levels and its chemical components over a period of more than one year in the Free State capital, Bloemfontein. Particulate matter was collected on PFTE filters, which were then analysed gravimetrically, by smoke stain reflectometry and X-ray fluorescence. The average PM2.5 concentration for the study period was 11μg/m3, which exceeded the World Health Organization (WHO) annual guideline limit (5μg/m3), but not the annual South African National Ambient Air Quality Standard (20μg/m3). The daily WHO guideline (15μg/m3) was exceeded on 28days, but not the daily South African standard (40μg/m3). The average soot concentration was 1.2μg/m3. The five most abundant trace elements detected in the PM2.5 filter samples were K, Ca, Si, S and Fe.
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| 13. |
- van der Westhuizen, Deidre, et al.
(författare)
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Source apportionment of fine atmospheric particles in Bloemfontein, South Africa, using positive matrix factorization
- 2024
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Ingår i: ENVIRONMENTAL MONITORING AND ASSESSMENT. - 0167-6369 .- 1573-2959. ; 196:2
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Tidskriftsartikel (refereegranskat)abstract
- Air pollution is of major health and environmental concern globally and in South Africa. Studies on the sources of PM2.5 air pollution in low- and middle-income countries such as South Africa are limited. This study aimed to identify local and distant sources of PM2.5 pollution in Bloemfontein. PM2.5 samples were collected from June 16, 2020 to August 18, 2021. Trace element concentrations were determined by EDXRF spectroscopy. By use of the US EPA PMF 5.0 program, local sources were determined to be combustion/wood burning (49%), industry (22%), soil dust (10%), base metal/pyrometallurgical and traffic (9.6%) and water treatment/industry (9.4%). The HYSPLIT program was applied to determine distant PM2.5 source areas and the following clusters were identified: Mpumalanga province (52%), Northern Cape province (35%), Indian Ocean (8%) and Atlantic Ocean (6%). The majority of the air was found to come from the Mpumalanga province in the north-east, while the majority of local sources are ascribed to combustion/wood burning. Results from this study can be used to develop an Air Quality Management Plan for Bloemfontein.
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| 14. |
- Vasan, Ramachandran S, et al.
(författare)
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Genetic variants associated with cardiac structure and function : a meta-analysis and replication of genome-wide association data
- 2009
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Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 302:2, s. 168-178
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Echocardiographic measures of left ventricular (LV) structure and function are heritable phenotypes of cardiovascular disease. OBJECTIVE: To identify common genetic variants associated with cardiac structure and function by conducting a meta-analysis of genome-wide association data in 5 population-based cohort studies (stage 1) with replication (stage 2) in 2 other community-based samples. DESIGN, SETTING, AND PARTICIPANTS: Within each of 5 community-based cohorts comprising the EchoGen consortium (stage 1; n = 12 612 individuals of European ancestry; 55% women, aged 26-95 years; examinations between 1978-2008), we estimated the association between approximately 2.5 million single-nucleotide polymorphisms (SNPs; imputed to the HapMap CEU panel) and echocardiographic traits. In stage 2, SNPs significantly associated with traits in stage 1 were tested for association in 2 other cohorts (n = 4094 people of European ancestry). Using a prespecified P value threshold of 5 x 10(-7) to indicate genome-wide significance, we performed an inverse variance-weighted fixed-effects meta-analysis of genome-wide association data from each cohort. MAIN OUTCOME MEASURES: Echocardiographic traits: LV mass, internal dimensions, wall thickness, systolic dysfunction, aortic root, and left atrial size. RESULTS: In stage 1, 16 genetic loci were associated with 5 echocardiographic traits: 1 each with LV internal dimensions and systolic dysfunction, 3 each with LV mass and wall thickness, and 8 with aortic root size. In stage 2, 5 loci replicated (6q22 locus associated with LV diastolic dimensions, explaining <1% of trait variance; 5q23, 12p12, 12q14, and 17p13 associated with aortic root size, explaining 1%-3% of trait variance). CONCLUSIONS: We identified 5 genetic loci harboring common variants that were associated with variation in LV diastolic dimensions and aortic root size, but such findings explained a very small proportion of variance. Further studies are required to replicate these findings, identify the causal variants at or near these loci, characterize their functional significance, and determine whether they are related to overt cardiovascular disease.
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| 15. |
- Wichmann, Janine, et al.
(författare)
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Association between ambient temperature and acute myocardial infarction hospitalisations in Gothenburg, Sweden: 1985-2010
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- Cardiovascular disease (CVD) is the number one cause of death globally and evidence is steadily increasing on the role of non-traditional risk factors such as meteorology and air pollution. Nevertheless, many research gaps remain, such as the association between these non-traditional risk factors and subtypes of CVD, such as acute myocardial infarction (AMI). The objective of this study was to investigate the association between daily ambient temperature and AMI hospitalisations using a case-crossover design in Gothenburg, Sweden (1985-2010). A secondary analysis was also performed for out-of-hospital ischemic heart disease (IHD) deaths. Susceptible groups by age and sex were explored. The entire year as well as the warm (April-September) and cold periods (October-March) were considered. In total 28,215 AMI hospitalisations (of 22,475 people) and 21,082 out-of-hospital IHD deaths occurred during the 26-year study period. A linear exposure-response corresponding to a 3% and 7% decrease in AMI hospitalisations was observed for an inter-quartile range (IQR) increase in the 2-day cumulative average of temperature during the entire year (11 degrees C) and the warm period (6 degrees C), respectively, with and without adjustment for PM(1)(0), NO(2), NOx or O(3). No heat waves occurred during the warm period. No evidence of an association in the cold period nor any association between temperature and IHD deaths in the entire year, warm or cold periods--with and without adjusting for PM(1)(0), NO(2), NOx or O(3) was found. No susceptible groups, based on age or sex, were identified either. The inverse association between temperature and AMI hospitalisations (entire year and warm period) in Gothenburg is in accordance with the majority of the few other studies that investigated this subtype of CVD.
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| 16. |
- Wichmann, Janine, et al.
(författare)
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The effect of secondary inorganic aerosols, soot and the geographical origin of air mass on acute myocardial infarction hospitalisations in Gothenburg, Sweden during 1985-2010: A case-crossover study
- 2014
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Ingår i: Environmental Health: A Global Access Science Source. - 1476-069X. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- © 2014 Wichmann et al.; licensee BioMed Central Ltd. Background: The relative importance of different sources of air pollution for cardiovascular disease is unclear. The aims were to compare the associations between acute myocardial infarction (AMI) hospitalisations in Gothenburg, Sweden and 1) the long-range transported (LRT) particle fraction, 2) the remaining particle fraction, 3) geographical air mass origin, and 4) influence of local dispersion during 1985-2010. Methods. A case-crossover design was applied using lag0 (the exposure the same day as hospitalisation), lag1 (exposure one day prior hospitalisation) and 2-day cumulative average exposure (CA2) (mean of lag0 and lag1). The LRT fractions included PMion(sum of sulphate, nitrate and ammonium) and soot measured at a rural site. The difference between urban PM10(particulate matter with an aerodynamic diameter smaller than 10 μm) and rural PMionwas a proxy for locally generated PM10(PMrest). The daily geographical origin of air mass was estimated as well as days with limited or effective local dispersion. The entire year was considered, as well as warm and cold periods, and different time periods. Results: In total 28 215 AMI hospitalisations occurred during 26 years. PM10, PMion, PMrestand soot did not influence AMI for the entire year. In the cold period, the association was somewhat stronger for PMrestthan for urban PM10;the strongest associations were observed during 1990-2000 between AMI and CA2 of PMrest(6.6% per inter-quartile range (IQR), 95% confidence interval 2.1 to 11.4%) and PM10(4.1%, 95% CI 0.2% - 8.2%). Regarding the geographical air mass origins there were few associations. Days with limited local dispersion showed an association with AMI in the cold period of 2001-2010 (6.7%, 95% CI 0.0% - 13.0%). Conclusions: In the cold period, locally generated PM and days with limited local dispersion affected AMI hospitalisations, indicating importance of local emissions from e.g. traffic.
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