| 1. |
- Gruzieva, Olena, et al.
(författare)
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Comparison of measured residential black carbon levels outdoors and indoors with fixed-site monitoring data and with dispersion modelling
- 2021
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 28:13, s. 16264-16271
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Tidskriftsartikel (refereegranskat)abstract
- Epidemiologic studies on health effects of air pollution usually rely on time-series of ambient monitoring data or on spatially modelled levels. Little is known how well these estimate residential outdoor and indoor levels. We investigated the agreement of measured residential black carbon (BC) levels outdoors and indoors with fixed-site monitoring data and with levels calculated using a Gaussian dispersion model. One-week residential outdoor and indoor BC measurements were conducted for 15 families living in central Stockholm. Time-series from urban background and street-level monitors were compared to these measurements. The observed weekly concentrations were also standardized to reflect annual averages, using urban background levels, and compared spatially to long-term levels as estimated by dispersion modelling. Weekly average outdoor BC level was 472 ng/m3 (range 261-797 ng/m3). The corresponding fixed-site urban background and street levels were 313 and 1039 ng/m3, respectively. Urban background variation explained 50% of the temporal variation in residential outdoor levels averaged over 24 h. Modelled residential long-term outdoor levels were on average comparable with the standardized measured home outdoor levels, and explained 49% of the spatial variability. The median indoor/outdoor ratio across all addresses was 0.79, with no difference between day and night time. Common exposure estimation approaches in the epidemiology of health effects related to BC displayed high validity for residencies in central Stockholm. Urban background monitored levels explained half of the outdoor day-to-day variability at residential addresses. Long-term dispersion modelling explained half of the spatial differences in outdoor levels. Indoor BC concentrations tended to be somewhat lower than outdoor levels.
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| 2. |
- Gruzieva, Olena, et al.
(författare)
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Comparison of personal exposure to black carbon levels with fixed-site monitoring data and with dispersion modelling and the influence of activity patterns and environment
- 2024
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Ingår i: Journal of Exposure Science and Environmental Epidemiology. - 1559-0631 .- 1559-064X.
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Tidskriftsartikel (refereegranskat)abstract
- Background: Short-term studies of health effects from ambient air pollution usually rely on fixed site monitoring data or spatio-temporal models for exposure characterization, but the relation to personal exposure is often not known.Objective: We aimed to explore this relation for black carbon (BC) in central Stockholm.Methods: Families (n = 46) with an infant, one parent working and one parent on parental leave, carried battery-operated BC instruments for 7 days. Routine BC monitoring data were obtained from rural background (RB) and urban background (UB) sites. Outdoor levels of BC at home and work were estimated in 24 h periods by dispersion modelling based on hourly real-time meteorological data, and statistical meteorological data representing annual mean conditions. Global radiation, air pressure, precipitation, temperature, and wind speed data were obtained from the UB station. All families lived in the city centre, within 4 km of the UB station.Results: The average level of 24 h personal BC was 425 (s.d. 181) ng/m3 for parents on leave, and 394 (s.d. 143) ng/m3 for working parents. The corresponding fixed-site monitoring observations were 148 (s.d. 139) at RB and 317 (s.d. 149) ng/m3 at UB. Modelled BC levels at home and at work were 493 (s.d. 228) and 331 (s.d. 173) ng/m3, respectively. UB, RB and air pressure explained only 21% of personal 24 h BC variability for parents on leave and 25% for working parents. Modelled home BC and observed air pressure explained 23% of personal BC, and adding modelled BC at work increased the explanation to 34% for the working parents.Impact: Short-term studies of health effects from ambient air pollution usually rely on fixed site monitoring data or spatio-temporal models for exposure characterization, but the relation to actual personal exposure is often not known. In this study we showed that both routine monitoring and modelled data explained less than 35% of variability in personal black carbon exposure. Hence, short-term health effects studies based on fixed site monitoring or spatio-temporal modelling are likely to be underpowered and subject to bias.
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| 3. |
- Hagenbjörk-Gustafsson, Annika, et al.
(författare)
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Determinants of personal exposure to some carcinogenic substances and nitrogen dioxide among the general population in five Swedish cities
- 2014
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Ingår i: Journal of Exposure Science and Environmental Epidemiology. - : Springer Science and Business Media LLC. - 1559-0631 .- 1559-064X. ; 24:4, s. 437-443
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Tidskriftsartikel (refereegranskat)abstract
- Environmental levels of airborne carcinogenic and related substances are comparatively better known than individual exposure and its determinants. We report on a personal monitoring program involving five Swedish urban populations. The aim of the program was to investigate personal exposure to benzene, 1,3-butadiene, formaldehyde, and nitrogen dioxide (NO2). The measurements were performed among 40 inhabitants during seven consecutive days, in one urban area each year, during 2000-2008. The estimated population exposure levels were 1.95 mu g/m(3) for benzene, 0.56 mu g/m(3) for 1,3-butadiene, 19.4 mu g/m(3) for formaldehyde, and 14.1,mu g/m(3) for NO2. Statistical analysis using a mixed-effects model revealed that time spent in traffic and time outdoors contributed to benzene and 1,3- butadiene exposure. For benzene, refueling a car was an additional determinant influencing the exposure level. Smoking or environmental tobacco smoke were significant determinants of exposure to NO2, benzene, and 1, 3-butadiene. Those with a gas stove had higher NO2 exposure. Living in a single-family house increased the exposure to formaldehyde significantly. In a variance component model, the between-subject variance dominated for 1,3-butadiene and formaldehyde, whereas the between-city variance dominated for NO2. For benzene, the between-subject and between-cities variances were similar.
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| 4. |
- Merritt, Anne-Sophie, et al.
(författare)
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Cat and house dust mite allergen content is stable in frozen dust over time
- 2013
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Ingår i: Environmental Science and Technology. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 0013-936X .- 1520-5851.
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dust from indoor environments consists of animal allergens, pollen, endotoxins and other substances which may exacerbate symptoms in sensitive individuals. In prospective cohort studies, dust is often collected from indoor environments in order to assess allergen exposure and possible relationships to health outcomes. Typically, large numbers of samples are collected and kept frozen until further analysis, sometimes several years later. To date, there is insufficient knowledge about what happens to the dust and its contents during storage. Objectives: In the present study, our aim was to analyse allergen content over a 30 month period frozen dust collected from beds in homes in order to simulate a study design of exposure assessment commonly used in epidemiological studies. Methods: Thirty-seven dust samples from mattresses in homes were collected using a Duststream dust collector. Each dust sample was subdivided into six aliquots. One tube (baseline) was extracted and analysed for cat and HDM allergen content using ELISA, all other tubes were stored at -80°C until further handling. Approximately every six months (6, 12, 18 and 30 months), dust from one tube was thawed, extracted and analysed the same way. Data was log-transformed and analysed using linear regression. Results: No trend for decreasing or increasing cat (p=0.606) or house dust mite (p=0.928)allergen levels could be observed over time. Levels of cat allergen were considerably higher in mattresses from homes with cats compared to homes without cats (p<0.001). Conclusion: It is important to assess the allergen stability in dust before designing costly and labour-intensive studies of allergen exposure and health outcomes, commonly used in environmental epidemiology. Although the present study showed that cat and HDM allergens 3 remained stable in dust stored at -80°C during a 2.5 year period, analyses of other allergens or substances in frozen dust is desirable as well as evaluating the effect of longer storage times.
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| 5. |
- Merritt, Anne-Sophie, et al.
(författare)
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Personal exposure to black carbon in Stockholm, using different intra-urban transport modes
- 2019
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 674, s. 279-287
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Tidskriftsartikel (refereegranskat)abstract
- The traffic microenvironment has been shown to be a major contributor to the total personal exposure of black carbon (BC), and is key to local actions aiming at reducing health risks associated with such exposure. The main aim of the study was to get a better understanding of the determinants of traffic-related personal exposure to BC in an urban environment. Personal exposure to ambient levels of BC was monitored while walking, cycling and traveling by bus or car along four streets and while cycling alternative routes simultaneously. Monitoring was performed during morning and afternoon peak hours and at midday, with a portable aethalometer recording one-minute mean values. In all, >4000 unique travel passages were performed. Stepwise Linear Regression was used to assess predictors to personal exposure levels of BC. The personal BC concentration ranged 0.03-37 mu g/m(3). The average concentrations were lowest while walking (1.7 mu g/m(3)) and highest traveling by bus (2.7 mu g/m(3)). However, only 22% of the variability could be explained by travel mode, urban background BC and wind speed. BC concentrations measured inside a car were on average 33% lower than measured simultaneously outside the car. Choosing an alternative bicycle route with less traffic resulted in up to 1.4 mu g/m(3) lower personal exposure concentrations. In conclusion, traveling by bus rendered the highest personal BC concentrations. But when taking travel time and inhalation rate into account, the travel-related exposure dose was predicted to be highest during walking and cycling. It is however probable that the benefits from physical activity outweigh health risks associated with this higher exposure dose. It is clear that road traffic makes an important contribution to personal exposure to BC regardless of mode of intra-urban transport. Our data suggest that commuting along routes with lower BC levels would substantially decrease commuter's exposure.
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| 6. |
- Yazar, Mine, et al.
(författare)
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Cancerframkallandeämnen i tätortsluft 2009
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Cancerframkallande ämnen i tätortsluftär en studie som utförs på uppdrag avNaturvårdsverket. Projektet utförs i fem städer i Sverige (Stockholm, Göteborg, Malmö,Umeå och Lindesberg) och återkommer till samma stad ungefär vart femte år. Studiengenomfördes första gången i Stockholm 2002 och nu senast hösten 2009. Syftet är attundersöka allmänbefolkningens exponering för 1,3-butadien, bensen, formaldehyd ochkvävedioxid samt PM2.5 och ett antal polycykliska aromatiska kolväten (PAH), däriblandbens(a)pyren. I studien 2009 i Stockholm gjordes även ett tillägg med analys av kväveoxideroch sot. Resultaten används främst för att utvärdera miljökvalitetsmålet ”Frisk luft” och somunderlag för en förbättrad riskvärdering hos allmänbefolkningen. De ämnen som ingår istudien är vanliga i tätortsluft och kan ge olika symtom i luftvägar, ögon och slemhinnor, geupphov till hjärt- kärlsjukdom samt vara cancerframkallande i höga koncentrationer.Fyrtio deltagare rekryterades slumpmässigt till studien för personburna mätningar under envecka varav 20 utförde en upprepad mätning några veckor senare. Parallellt med depersonburna mätningarna gjordes stationära mätningar vid två referensplatser, urban bakgrund(taknivå, Wollmar Yxkullsgatan) och vid trafikerad gata (Hornsgatan). Partikelmätningargjordes med pump i 20 av deltagarnas vardagsrum under två dygn och även samtidigt vid denurbana bakgrundsplatsen. Av deltagarna var 21 män och 19 kvinnor. Hälften bodde iStockholms innerstad och hälften utanför innerstaden. Medelåldern var 38 år och fem avdeltagarna var rökare. Större delen av deltagarnas tid (89 procent i mätomgång ett)tillbringades i olika inomhusmiljöer.För samtliga ämnen som ingick i studien var halterna högre vid trafikerad gata än vid urbanbakgrund. Kväveoxider och kvävedioxid samt 1,3-butadien och bensen samvarierade vidbägge referensplatser. Kväveoxider och kvävedioxid samvarierade även mellanreferensplatserna. Det fanns ett statistiskt säkerställt samband mellan PM2.5 och sot samtmellan PM2.5 och bens(a)pyren i den urbana bakgrunden. Bens(a)pyren korrelerade även medsot i urban bakgrund.Halter av 1,3-butadien var statistiskt säkerställt högre för rökare jämfört med icke-rökare.Formaldehydhalterna var lägre hos de deltagare som bodde i innerstaden, jämfört med demsom bodde utanför innerstaden. Det fanns även en signifikant skillnad mellan deltagare medoch utan gasspis i hemmet, där de med gasspis hade högre halter av kväveoxider ochkvävedioxid.Halterna för de personburna mätningarna av kväveoxider samvarierade statistiskt säkert medde uppmätta halterna i urban bakgrund. Inga andra ämnen som mättes personburet uppvisadenågot samband med referensplatsmätningarna. Det fanns inget samband mellan partiklarnasom mättes inomhus hos deltagarna och utomhus på referensplatsen i urban bakgrund.Däremot fanns ett signifikant samband mellan inom- och utomhushalterna av bens(a)pyren.Halterna för de personburna mätningarna hade minskat mellan år 2002 (då studien tidigareutförts i Stockholm) och 2009 för samtliga ämnen som undersöktes i studien. Vid bäggereferensplatserna var halterna i samma nivå eller lägre för 1,3-butadien, bensen, formaldehyd,kvävedioxid och bens(a)pyren, förutom för formaldehyd vid trafikerad gata där det skett enökning.
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