| 1. |
- Modig, Lars, 1976-
(author)
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Asthma, rhinitis, and asthma-related symptoms in relation to vehicle exhaust using different exposure metrics
- 2009
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Doctoral thesis (other academic/artistic)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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| 2. |
- Hagenbjörk-Gustafsson, Annika, et al.
(author)
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Cancerframkallande ämnen i tätortsluft : Personlig exponering och bakgrundsmätningar i Umeå 2007
- 2008
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Reports (other academic/artistic)abstract
- Allmänbefolkningens exponering för några cancerframkallande luftföroreningar undersöktes iUmeå under perioden 15 oktober till 18 december 2007. Studien som är en del iNaturvårdsverkets hälsorelaterade miljöövervakning, genomfördes som personburna 7-dygnsmätningar på 40 slumpvis utvalda personer boende i Umeå tätort. Mätningenupprepades på 20 personer. Under samma period gjordes stationära mätningar på två platser(bibliotekstaket och E4) i centrala Umeå. De personburna och stationära mätningarnaomfattade bensen, 1,3-butadien, formaldehyd och kvävedioxid och utfördes meddiffusionsprovtagare. Inomhus hos 20 personer gjordes även 2-dygnsmätningar av partiklar(PM2.5) och polycykliska aromatiska kolväten (PAH) parallellt med mätningar vid den urbanabakgrundsstationen (bibliotekstaket).Deltagarfrekvensen var 81 %, deltagarna tillbringade i medeltal 89 % av mätveckan inomhus.Tre av deltagarna var rökare och övriga deltagare hade begränsad exponeringstid för passivrökning. En deltagare hade yrkesmässig exponering för de undersökta ämnena.Det fanns en signifikant korrelation mellan halter av bensen och 1,3-butadien uppmättpersonburet, men för övriga ämnen sågs ingen korrelation. Rökning och boendeform hadeingen påverkan på exponeringen. Vid jämförelse med 2001 års mätning i Umeå har personligexponering för bensen och 1,3-butadien minskat signifikant, medan exponeringen ökat förkvävedioxid.Vid E4 fanns ett signifikant samband mellan bensen och 1,3-butadienhalter som intenoterades vid bibliotekstaket. Bensenhalterna ligger i nivå med 2001 års mätning vidutomhusstationerna, medan kvävedioxidhalterna minskat, om än inte signifikant. Vidbibliotekstaket har 1,3-butadien- och formaldehydhalterna minskat signifikant.För bensen och kvävedioxid var korrelationen hög och signifikant mellan den personligamedelexponeringen för varje mätvecka och halter mätt stationärt. Motsvarande korrelation förformaldehyd och 1,3-butadien var låg.På grund av låga halter PM2.5 och PAH vid inomhusmätningarna beslutades hösten 2008 atten upprepad mätning i vardagsrum hos de fem individer som hade lägst halt partiklar skullegenomföras. Partikelhalterna (PM2.5) var högre (median = 4,1 μg/m3) vid den upprepademätningen i jämförelse med den första mätomgången. Medianhalten bens(a)pyren var vid denupprepade mätningen 36 pg/m3, och även för övriga partikulära PAH var halterna högre.
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| 3. |
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| 4. |
- Modig, Gustaf, et al.
(author)
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Homogenization-induced degradation of hydrophobically modified starch determined by asymmetrical flow field-flow fractionation and multi-angle light scattering
- 2006
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In: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 20:7, s. 1087-1095
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Journal article (peer-reviewed)abstract
- High-pressure homogenization of modified starches is a type of treatment used within the food and pharmaceutical industry for the production of emulsions. Such intense mechanical treatment may, however, influence the size and size distribution of the starch polymer, which may affect the properties of the emulsions. In this work, asymmetrical flow field-flow fractionation (AsFIFFF) connected on-line to a multi-angle light scattering detector (MALS) was used to study the influence of high-pressure homogenization upon molar mass and root-mean-square (r.m.s.) radius of three different octenyl succinate anhydride (OSA) starch samples originating from potato. The homogenization at constant pressure resulted in a significant decrease of both molar mass and r.m.s. radius. The magnitude of the change in molar mass and r.m.s. radius could be correlated to the initial size of the OSA starch and the energy dissipation rate of the homogenization treatment.
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| 5. |
- Modig, Lars, et al.
(author)
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Akuta luftvägsbesvär bland vuxna astmatiker i förhållande till tidsmässiga variationer i luftföroreningshalter - en studie inom den hälsorelaterade miljöövervakningen 2005
- 2006
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Reports (other academic/artistic)abstract
- Denna dagboksstudie utgör en del i Naturvårdsverkets hälsorelaterade miljöövervakning, ochsyftar till att studera om och hur symtom och besvär bland astmatiker samvarierar medkorttidsvariationer i luftföroreningshalter i utomhusluften.Studien bygger på tre paneler med totalt 64 vuxna astmatiker (16-70 år) fördelade på städernaUmeå, Uppsala och Göteborg. Deltagarna identifierades via en bredare miljöenkät där de somsvarade ja på frågan om läkardiagnostiserad astma inbjöds att delta i dagboksstudien.Deltagarna besvarade dagligen under 11 veckor ett dagboksblad bestående av 15 frågorrörande astmarelaterade symtom, astmamedicinering, upplevda besvär osv. Halten avluftföroreningar beskrivs som dygnsmedelhalterna av kvävedioxid (NO2) och partiklar mättsom PM10 i urban bakgrundsluft och har inhämtats från respektive kommun.Resultaten visar då samtliga städer inkluderades i analysen på ett statistiskt säkerställtsamband mellan NO2-halten samma dag (lag 0) och att man behövt stanna hemma på grundav luftvägsbesvär samt att man haft pip i bröstet. Motsvarande resultat sågs även då NO2-halten beskrevs som medelvärdet av dagens och gårdagens halt (lag 01). I de separataanalyserna för respektive stad sågs också ett säkerställt samband mellan NO2-halten (lag01)och risken att få stanna hemma på grund av luftvägsbesvär samt att ha pip i bröstet i Umeå,men inte i de två övriga städerna. För PM10 sågs inga säkerställda samband.
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| 6. |
- Modig, Lars, et al.
(author)
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Besvärsförekomst i relation till luftföroreningshalter i tre svenska städer. En studie inom den hälsorelaterade miljöövervakningen 2005.
- 2005
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Reports (other academic/artistic)abstract
- Denna enkätstudie utgör en del i Naturvårdsverkets hälsorelaterade miljöövervakning, ochsyftar till att beskriva hur människor upplever sin omgivningsmiljö med avseende på främstluftkvalitet.Enkäten bestod av 22 frågor främst rörande upplevelsen av olika miljöfaktorer i närheten avbostaden. Urvalet av deltagare gjordes slumpmässigt bland befolkningen (16-70 år) i decentrala delarna av tre svenska städer (Umeå, Göteborg och Uppsala). Halten av luftföroreningarindikerad med avgasmarkören kvävedioxid (NO2) beräknades som vinterhalvårsmedelhalterför varje stad med detaljerade meteorologiska spridningsmodeller. Medhjälp av koordinaterna för den fastighet på vilken respektive deltagare var skriven, kundevarje deltagare tillskrivas en beräknad vinterhalvårsmedelhalt.Ungefär 20 % av nära 2800 deltagare skattade störningen av avgaser från vägtrafik till mer än4 på en 11-gradig skala, medan störningen på grund av vedeldning på dessa orter var betydligtmindre omfattande. Analysen av den modellerade luftföroreningshalten och andelen mycketstörda av avgaser från vägtrafik, visade på ett statistiskt säkerställt samband där oddset attskatta sig mycket störd ökade med cirka 14 % per μg/m3 ökning av vinterhalvårsmedelhaltenav NO2. Motsvarande analys av frågan om hur ofta deltagarna upplevde luften som irriteranderesulterade i ett säkerställt samband med en ökning av oddset med 9 % per μg/m3 ökning avNO2-halten.Resultaten från enkäten visade också att låg temperatur och drag var de inomhusfaktorer somstörst andel av deltagarna angav som besvärande, medan vägtrafik och grannar var debullerkällor som upplevdes som mest störande.
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| 7. |
- Modig, Lars, 1976-, et al.
(author)
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Perceived annoyance and asthmatic symptoms in relation to vehicle exhaust levels outside home : a cross-sectional study
- 2007
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In: Environmental Health. - 1476-069X. ; 6, s. 29-
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Journal article (peer-reviewed)abstract
- BACKGROUND: Exhaust emissions from vehicles is a well known problem with both epidemiological and experimental studies showing increasing adverse health effects with elevating levels. Many of the studies concerning vehicle exhausts and health are focused on health outcomes where the proportion attributed to exhaust is low, while there is less information on early and more frequent subjective indicators of adverse effects.METHODS: The primary aim of this study was to study perceived annoyance in relation to vehicle exhaust concentrations using modelled levels of nitrogen dioxide outside the home as an indicator with high spatial resolution. Almost 2800 persons in a random sample from three Swedish cities (Umea, Uppsala and Gothenburg) responded to our questionnaire. Questions were asked to determine the degree of annoyance related to vehicle exhausts and also the prevalence of irritating and asthmatic symptoms. Exposure was described for each participants home address by meteorological dispersion models with a 50 meter resolution.RESULTS: We found a significant increase of peoples' self-assessed annoyance with rising levels of NO2. The odds of being very annoyed by vehicle exhausts increased by 14% per 1 microg/m3 increase of the NO2 level (odds ratio (OR) = 1.14, 95% confidence interval (CI) = 1.11-1.18), and the odds of reporting the air as daily or almost daily irritating increased by 9% (OR = 1.09, 95% CI = 1.05-1.13). Also the odds of reporting asthmatic symptoms increased significantly with elevated NO2 levels (OR = 1.04, 95% CI = 1.01-1.07).CONCLUSION: This study found the degree of annoyance related to vehicle exhaust and irritating and asthmatic symptoms to be significantly dependent on the levels of traffic related pollutants outside the home. The detailed exposure assessment lowers the degree of misclassification as compared to between-city analyses, which makes the results more accurate and applicable on the local scale.
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| 8. |
- Modig, Lars, 1976-, et al.
(author)
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Vehicle exhaust exposure in an incident case-control study of adult asthma
- 2006
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In: European Respiratory Journal. - Copenhagen : Munksgaard. - 0903-1936 .- 1399-3003. ; 28:1, s. 75-81
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Journal article (peer-reviewed)abstract
- The objective of this case–control study was to evaluate whether traffic-related air pollution exposure at home increases the risk of asthma in adults and to compare two commonly used exposure variables and differences between urban and rural living. Incident cases of asthma and matched controls of subjects aged 20–60 yrs were recruited in Luleå, Sweden. In total 203 cases and 203 controls were enrolled in the study. Exposure was estimated by traffic flow and measured levels of outdoor nitrogen dioxide (NO2) in the surrounding environment of each home, respectively. The relationship between measured levels of NO2 and traffic flow was studied using linear regression. The results indicated a nonsignificant tendency between living in a home close to a high traffic flow and an increased risk of asthma. The association between asthma and measured NO2 was weak and not significant, but the skin-prick test result acted as an effect modifier with a borderline significant association among positives. The correlation between traffic flow and outdoor NO2 was low. The results suggest that living close to high traffic flows might increase the asthma incidence in adults, while the tendency for nitrogen dioxide was only seen among atopics. Traffic flow and nitrogen dioxide had a lower than expected correlation.
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| 9. |
- Modig, Lars, 1976-, et al.
(author)
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Vehicle exhaust outside the home and onset of asthma among adults
- 2009
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In: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 33:6, s. 1261-1267
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Journal article (peer-reviewed)abstract
- Few studies have investigated the relationship between vehicle exhaust and the new onset of asthma among adults. The aim of the present prospective cohort study was to investigate the relationship between the cumulative incidence of asthma and onset of asthma among adults and vehicle exhaust concentrations at home. Participants from three Swedish cities included in the Respiratory Health in Northern Europe cohort constituted the study population. Exposure at each participant's home was calculated using dispersion models. We also used <50 m distance to nearest major road as a more simple indicator of exposure. The adjusted model included 3,609 participants, of which 107 were classified as onset cases and 55 as true incident cases of asthma. There was a positive association between asthma onset (odds ratio (OR) per 10 microg x m(-3) 1.46, 95% confidence interval (CI) 1.07-1.99) and incident asthma (OR per 10 microg x m(-3) 1.54, 95% CI 1.00-2.36) and the levels of nitrogen dioxide (NO(2)), which remained statistically significant after adjusting for potential confounders. The relationship between asthma and NO(2) was not significantly modified by sex, hay fever or wheeze. The risk of developing asthma was also significantly related to living close to a major road. The current study suggests that elevated levels of vehicle exhaust outside the home increase the risk of onset and incident asthma among adults.
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| 10. |
- Modig-Wennerstad, K., et al.
(author)
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Association between offspring intelligence and parental mortality : A population-based cohort study of one million Swedish men and their parents
- 2008
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In: Journal of Epidemiology and Community Health. - : BMJ. - 0143-005X .- 1470-2738. ; 62:8, s. 722-727
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Journal article (peer-reviewed)abstract
- Background: An inverse association of IQ with mortality has been observed in previous studies. Analyses of associations between offspring's IQ and parental mortality in biological and non-biological family relations may shed light on genetic and environmental influences. Methods: In a target cohort of 1 235 375 Swedish men, 931 825 (75%) men had complete data on all variables used. IQ of offspring was measured at age 18 and mothers and fathers were followed, on average, for 21.2 years and 19.7 years, respectively, with respect to all-cause and cause-specific mortality (cardiovascular disease, coronary heart disease, stroke and diabetes). The analyses were conducted by proportional hazards regression with adjustment for parental occupation, education and income. Results: In adjusted analyses using IQ as a continuous variable over a standard nine-point scale, hazards ratio (HR) for all-cause mortality was 0.96 (95% CI 0.96 to 0.96) for fathers and 0.95 (0.95 to 0.95) for mothers. The corresponding HRs were 0.99 (0.97 to 1.00) for step-fathers and 0.97 (0.95 to 0.99) for step-mothers. In adjusted analyses, HRs for CVD mortality among fathers and mothers were 0.97 (0.96 to 0.97) and 0.94 (0.93 to 0.94) respectively. The corresponding HRs for diabetes mortality were 0.91 (0.89 to 0.92) among fathers and 0.85 (0.83 to 0.87) among mothers. Conclusions: The associations found in non-biological family relationships suggest shared environmental influences and/or assortative mating. Stronger IQ-mortality associations in biological than non-biological relationships suggest genetic influences. Stronger inverse offspring IQ-parental mortality associations in mothers than in fathers might be due to environmental factors or epigenetic mechanisms.
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