| 1. |
- 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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| 2. |
- Modig, Lars, 1976-
(författare)
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Asthma, rhinitis, and asthma-related symptoms in relation to vehicle exhaust using different exposure metrics
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Air pollution is a well known public health problem that involves both long-term and acute effects. An outcome associated with traffic-related air pollution is respiratory illness. Many studies have described the relationship between asthmatic symptoms and traffic-related air pollution; however, few have investigated the potential of air pollution to cause asthma itself, especially among adults. The overall aim of this thesis was to study the relationship between vehicle exhaust levels at home and the prevalence of self-reported annoyance and asthmatic symptoms, and the incidence of asthma and rhinitis. These relationships were evaluated using different indicators of exposure with a high spatial resolution. Three different data sets were used for the four papers included in this thesis. The first paper (paper I) is based on a questionnaire that was sent to a random selection of the adult population within three Swedish cities (Gothenburg, Uppsala, and Umeå) as part of the Swedish Environmental Protection Agency’s health-related environmental monitoring. The aim was to study the degree of self-reported annoyance and the prevalence of asthmatic symptoms in relation to the levels of vehicle exhaust outside the home. The level of exposure was described using modeled levels of nitrogen dioxide (NO2) as the exposure indicator. The second paper (paper II) is based on new asthma cases identified within the Obstructive Lung disease In Northern Sweden (OLIN) study, each with a matched referent. The aim of this study was to analyze if new cases of asthma had higher levels of vehicle exhaust outside the home compared to the population controls. Exposure was assessed using both measured levels of NO2 outside each home, and by summarizing the amount of traffic within a 200 metre buffer surrounding each participant’s home. Papers III and IV were based on the Respiratory Health in Northern Europe (RHINE) Cohort, a prospective cohort of adults included in 1990 and followed up with in 1999. The proportion of new cases of asthma (papers III and IV) and rhinitis (paper IV) were identified based on the answers from the initial and follow-up questionnaires. In paper III, exposure was assessed by using meteorological dispersion models to calculate the levels of NO2 outside each home as an indicator of the levels of vehicle exhaust. As an alternative indicator, the distance from each participant’s home to the nearest major road was calculated using geographical information system (GIS) tools. The exposure assessment in paper IV was also based on meteorological dispersion models, but expressed the levels of vehicle exhaust as particle mass concentration. The results show that the levels of vehicle exhaust outside the home are significantly correlated with the degree of self-reported annoyance and the prevalence of asthmatic symptoms, and also with the risk of developing asthma, but not rhinitis, among adults. The odds ratio (OR) for high annoyance to vehicle exhaust and reporting asthmatic symptoms was 1.14 (95% Confidence Interval, CI 1.11-1.18) and 1.04 (95% CI 1.01-1.07) per 1 µg/m3 increase in the NO2 level outside the home, respectively. Paper II showed there was a non-significant tendency for increased risk of developing asthma among those living with high levels of vehicle exhaust outside their home. This finding was then supported by papers III and IV, showing a significant relationship between the onset of asthma and the mean (winter) levels of NO2 outside the home (OR=1.46, 95% CI 1.07-1.99 per 10 µg/m3) and the levels of vehicle exhaust particles outside the home. In paper III, living close to a major road was significantly related to the risk of developing asthma. No significant results were shown between vehicle exhaust and rhinitis. In conclusion, vehicle exhaust outside the home is associated with the prevalence of annoyance and asthmatic symptoms, and with the risk of developing asthma, but not rhinitis, among adults.
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| 3. |
- Oudin, Anna, et al.
(författare)
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Traffic-Related Air Pollution and Dementia Incidence in Northern Sweden : A Longitudinal Study
- 2016
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Ingår i: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 124:3, s. 306-312
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Exposure to ambient air pollution is suspected to cause cognitive effects, but a prospective cohort is needed to study exposure to air pollution at the home address and the incidence of dementia.OBJECTIVES: We aimed to assess the association between long-term exposure to traffic-related air pollution and dementia incidence in a major city in northern Sweden.METHODS: Data on dementia incidence over a 15-year period were obtained from the longitudinal Betula study. Traffic air pollution exposure was assessed with a Land Use Regression Model with a spatial resolution of 50 m x 50 m. Annual mean nitrogen oxide levels at the residential address of the participants at baseline (the start of follow-up) was used as a marker for long-term exposure to air pollution.RESULTS: Out of 1806 participants at baseline, 191 were diagnosed with Alzheimer's disease during follow-up, and 111 were diagnosed with vascular dementia. Participants in the highest exposure group were more likely to be diagnosed with dementia (Alzheimer's disease or vascular dementia), with a Hazard Ratio (HR) of 1.43 (95% Confidence Interval (CI): 0.998, 2.05 for the highest versus lowest quartile). The estimates were similar for Alzheimer's disease (HR 1.38) and vascular dementia (HR 1.47). The HR for dementia associated for the third quartile versus the lowest quartile was 1.48 (95% CI: 1.03, 2.11). A sub-analysis that excluded a younger sample that had been re-tested after only 5 years of follow-up suggested stronger associations with exposure than in the full cohort (HR = 1.71; 95% CI: 1.08, 2.73 for the highest versus lowest quartile).CONCLUSIONS: If the associations we observed are causal, then air pollution from traffic might be an important risk factor for vascular dementia and Alzheimer's disease.
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| 4. |
- Xu, S. S., et al.
(författare)
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Long-term exposure to low-level air pollution and greenness and mortality in Northern Europe. The Life-GAP project
- 2023
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Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 181
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Tidskriftsartikel (refereegranskat)abstract
- Background: Air pollution has been linked to mortality, but there are few studies examining the association with different exposure time windows spanning across several decades. The evidence for the effects of green space and mortality is contradictory.Objective: We investigated all-cause mortality in relation to exposure to particulate matter (PM2.5 and PM10), black carbon (BC), nitrogen dioxide (NO2), ozone (O3) and greenness (normalized difference vegetation index NDVI) across different exposure time windows.Methods: The exposure assessment was based on a combination of the Danish Eulerian Hemispheric Model and the Urban Background Model for the years 1990, 2000 and 2010. The analysis included a complete case dataset with 9,135 participants from the third Respiratory Health in Northern Europe study (RHINE III), aged 40-65 years in 2010, with mortality follow-up to 2021. We performed Cox proportional hazard models, adjusting for potential confounders.Results: Altogether, 327 (3.6 %) persons died in the period 2010-2021. Increased exposures in 1990 of PM2.5, PM10, BC and NO2 were associated with increased all-cause mortality hazard ratios of 1.40 (95 % CI1.04-1.87 per 5 mu g/m3), 1.33 (95 % CI: 1.02-1.74 per 10 mu g/m3), 1.16 (95 % CI: 0.98-1.38 per 0.4 mu g/m3) and 1.17 (95 % CI: 0.92-1.50 per 10 mu g/m3), respectively. No statistically significant associations were observed between air pollution and mortality in other time windows. O3 showed an inverse association with mortality, while no association was observed between greenness and mortality. Adjusting for NDVI increased the hazard ratios for PM2.5, PM10, BC and NO2 exposures in 1990. We did not find significant interactions between greenness and air pollution metrics.Conclusion: Long term exposure to even low levels of air pollution is associated with mortality. Opening up for a long latency period, our findings indicate that air pollution exposures over time may be even more harmful than anticipated.
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| 5. |
- Zackrisson, Björn, et al.
(författare)
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Two-year results from a Swedish study on conventional versus accelerated radiotherapy in head and neck squamous cell carcinoma - The ARTSCAN study
- 2011
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Ingår i: Radiotherapy and Oncology. - : Elsevier. - 0167-8140 .- 1879-0887. ; 100:1, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Studies on accelerated fractionation (AF) in head and neck cancer have shown increased local control and survival compared with conventional fractionation (CF), while others have been non-conclusive. In 1998 a national Swedish group decided to perform a randomised controlled clinical study of AF. Materials and methods: Patients with verified squamous cell carcinoma of the oral cavity, oropharynx, larynx (except glottic T1-T2, N0) and hypopharynx were included. Patients with prior chemotherapy or surgery were excluded. Patients were randomised to either CF (2Gy/day, 5days/week for 7 weeks, total dose 68Gy) or to AF (1.1Gy+2.0Gy/day, 5days/week for 4.5weeks, total dose 68Gy). An extensive quality assurance protocol was followed throughout the study. The primary end point was loco-regional tumour control (LRC) at two years after treatment. RESULTS: The study was closed in 2006 when 750 patients had been randomised. Eighty-three percent of the patients had stages III-IV disease. Forty eight percent had oropharyngeal, 21% laryngeal, 17% hypopharyngeal and 14% oral cancers. There were no significant differences regarding overall survival (OS) or LRC between the two regimens. The OS at two years was 68% for AF and 67% for CF. The corresponding figures for LRC were 71% and 67%, respectively. There was a trend towards improved LRC for oral cancers treated (p=0.07) and for large tumours (T3-T4) (p=0.07) treated with AF. The AF group had significantly worse acute reactions, while there was no significant increase in late effects. Conclusion: Overall the AF regimen did not prove to be more efficacious than CF. However, the trend towards improved results in AF for oral cancers needs to be further investigated.
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| 6. |
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| 7. |
- Amin, H., et al.
(författare)
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Indoor Airborne Microbiome and Endotoxin: Meteorological Events and Occupant Characteristics Are Important Determinants
- 2023
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 57:32, s. 11750-11766
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Tidskriftsartikel (refereegranskat)abstract
- Minimal research exists onthe factors influencing the indoorbacterial community. Despite their proposed importance for health,here we report environmental factors influencing the composition ofthe indoor bacterial communities. Airborne bacteria and endotoxin may affect asthma andallergies.However, there is limited understanding of the environmental determinantsthat influence them. This study investigated the airborne microbiomesin the homes of 1038 participants from five cities in Northern Europe:Aarhus, Bergen, Reykjavik, Tartu, and Uppsala. Airborne dust particleswere sampled with electrostatic dust fall collectors (EDCs) from theparticipants' bedrooms. The dust washed from the EDCs'clothes was used to extract DNA and endotoxin. The DNA extracts wereused for quantitative polymerase chain (qPCR) measurement and 16SrRNA gene sequencing, while endotoxin was measured using the kineticchromogenic limulus amoebocyte lysate (LAL) assay. The results showedthat households in Tartu and Aarhus had a higher bacterial load anddiversity than those in Bergen and Reykjavik, possibly due to elevatedconcentrations of outdoor bacterial taxa associated with low precipitationand high wind speeds. Bergen-Tartu had the highest difference (ANOSIM R = 0.203) in & beta; diversity. Multivariate regressionmodels showed that & alpha; diversity indices and bacterial and endotoxinloads were positively associated with the occupants' age, numberof occupants, cleaning frequency, presence of dogs, and age of thehouse. Further studies are needed to understand how meteorologicalfactors influence the indoor bacterial community in light of climatechange.
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| 8. |
- Andersson, Martin, et al.
(författare)
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Heavy vehicle traffic is related to wheeze among schoolchildren : a population-based study in an area with low traffic flows
- 2011
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Ingår i: Environmental Health. - London : BioMed Central. - 1476-069X. ; 10:91
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Tidskriftsartikel (refereegranskat)abstract
- Background: An association between traffic air pollution and respiratory symptoms among children has been reported. However, the effects of traffic air pollution on asthma and wheeze have been very sparsely studied in areas with low traffic intensity in cold climate with poor dispersion. We evaluated the impact of vehicle traffic on childhood asthma and wheeze by objective exposure assessment.Methods: As a part of the Obstructive Lung Disease in Northern Sweden (OLIN) studies, a questionnaire was sent to the families of all children attending first or second grade in Luleå (72,000 inhabitants) in Northern Sweden in 2006. The age of the children was 7-8 years and the participation rate was 98% (n = 1357). Skin prick tests were performed in 1224 (89%) children. The home addresses were given geographical coordinates and traffic counts were obtained from the local traffic authorities. A proximity model of average daily traffic and average daily heavy vehicle traffic within 200 meters from each participant's home address was used. The associations between traffic exposure and asthma and wheeze, respectively, were analysed in an adjusted multiple logistic regression model.Results: Exposure to high traffic flows was uncommon in the study area; only 15% of the children lived within 200 meters from a road with a traffic flow of ≥8000 vehicles per day. Living closer than 200 meters from a road with ≥500 heavy vehicles daily was associated with current wheeze, odds ratio 1.7 (confidence interval 1.0-2.7). A dose-response relation was indicated. An increased risk of asthma was also seen, however not significant, odds ratio 1.5 (confidence interval 0.8-2.9). Stratified analyses revealed that the effect of traffic exposure was restricted to the non-sensitized phenotype of asthma and wheeze. The agreement between self-reported traffic exposure and objective measurements of exposure was moderate.Conclusions: This study showed that already at low levels of exposure, vehicle traffic is related to an increased risk of wheeze among children. Thus, the global burden of traffic air pollution may be underestimated.
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| 9. |
- Beelen, Rob, et al.
(författare)
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Effects of long-term exposure to air pollution on natural-cause mortality : an analysis of 22 European cohorts within the multicentre ESCAPE project
- 2014
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Ingår i: The Lancet. - : Elsevier. - 0140-6736 .- 1474-547X. ; 383:9919, s. 785-795
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Tidskriftsartikel (refereegranskat)abstract
- Background Few studies on long-term exposure to air pollution and mortality have been reported from Europe. Within the multicentre European Study of Cohorts for Air Pollution Effects (ESCAPE), we aimed to investigate the association between natural-cause mortality and long-term exposure to several air pollutants. Methods We used data from 22 European cohort studies, which created a total study population of 367 251 participants. All cohorts were general population samples, although some were restricted to one sex only. With a strictly standardised protocol, we assessed residential exposure to air pollutants as annual average concentrations of particulate matter (PM) with diameters of less than 2.5 mu m (PM2.5), less than 10 mu m (PM10), and between 10 mu m and 2.5 mu m (PMcoarse), PM2.5 absorbance, and annual average concentrations of nitrogen oxides (NO2 and NOx), with land use regression models. We also investigated two traffic intensity variables-traffic intensity on the nearest road (vehicles per day) and total traffic load on all major roads within a 100 m buff er. We did cohort-specific statistical analyses using confounder models with increasing adjustment for confounder variables, and Cox proportional hazards models with a common protocol. We obtained pooled effect estimates through a random-effects meta-analysis. Findings The total study population consisted of 367 251 participants who contributed 5 118 039 person-years at risk (average follow-up 13.9 years), of whom 29 076 died from a natural cause during follow-up. A significantly increased hazard ratio (HR) for PM2.5 of 1.07 (95% CI 1.02-1.13) per 5 mu g/m(3) was recorded. No heterogeneity was noted between individual cohort effect estimates (I-2 p value=0.95). HRs for PM2.5 remained significantly raised even when we included only participants exposed to pollutant concentrations lower than the European annual mean limit value of 25 mu g/m(3) (HR 1.06, 95% CI 1.00-1.12) or below 20 mu g/m(3) (1.07, 1.01-1.13). Interpretation Long-term exposure to fine particulate air pollution was associated with natural-cause mortality, even within concentration ranges well below the present European annual mean limit value.
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| 10. |
- Bergman, Lars R., et al.
(författare)
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High IQ in early adolescence and career success in adulthood : Findings from a Swedish longitudinal study
- 2014
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Ingår i: Research in Human Development. - : Informa UK Limited. - 1542-7609 .- 1542-7617. ; 11:3, s. 165-185
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Tidskriftsartikel (refereegranskat)abstract
- To what extent do intellectually talented adolescents pursue educational and vocational careers that match their intellectual resources? Career outcomes were compared between groups within different IQ ranges with a focus on comparing those with high IQ (top 10%, IQ > 119) to those with average IQ. Data were analyzed from the longitudinal Swedish IDA study (N = 1,326) with career outcomes measured in midlife (age 43–47). To obtain at least a master’s degree was almost 10 times more common for those of high IQ than for those of average IQ. Still, the proportion of high-IQ adolescents who did this was not high (13% of females, 34% of males) and as much as 20% of them did not even graduate from 3-year high school. For men only, there was a graded raise in income by IQ group.Within the high-IQ group there was no significant relationship between parents’ socioeconomic status and income. For men, high IQ predicted a strongly increased income/vocational level in midlife beyond what was predicted from a linear model of the IQ-outcome relationship.
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