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- Lindqvist, Magnus, et al.
(författare)
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Natural course of pollen-induced allergic rhinitis from childhood to adulthood : A 20-year follow up.
- 2023
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - 0105-4538 .- 1398-9995.
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Allergic rhinitis (AR) is one of the most common chronic diseases worldwide. There are limited prospective long-term data regarding persistency and remission of AR. The objective of this study was to investigate the natural course of pollen-induced AR (pollen-AR) over 20 years, from childhood into early adulthood.METHODS: Data from 1137 subjects in the Barn/Children Allergi/Allergy Milieu Stockholm Epidemiologic birth cohort (BAMSE) with a completed questionnaire regarding symptoms, asthma, treatment with allergen immunotherapy (AIT) and results of allergen-specific IgE for inhalant allergens at 4, 8, 16 and 24 years were analyzed. Pollen-AR was defined as sneezing, runny, itchy or blocked nose; and itchy or watery eyes when exposed to birch and/or grass pollen in combination with allergen-specific IgE ≥0.35kUA /L to birch and/or grass.RESULTS: Approximately 75% of children with pollen-AR at 4 or 8 years had persistent disease up to 24 years, and 30% developed asthma. The probability of persistency was high already at low levels of pollen-specific IgE. The highest rate of remission from pollen-AR was seen between 16 and 24 years (21.5%); however, the majority remained sensitized. This period was also when pollen-specific IgE-levels stopped increasing and the average estimated annual incidence of pollen-AR decreased from 1.5% to 0.8% per year.CONCLUSION: Children with pollen-AR are at high risk of persistent disease for at least 20 years. Childhood up to adolescence seems to be the most dynamic period of AR progression. Our findings underline the close cross-sectional and longitudinal relationship between sensitization, AR and asthma.
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- Mattsson, Magnus, 1964-, et al.
(författare)
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Ventilation filter efficiency for particles and grass pollen allergens
- 2009
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Ingår i: Proceedings of the 9th International Healthy Buildings Conference and Exhibition.
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Konferensbidrag (refereegranskat)abstract
- In an experimental study, commonly used ventilation fine filters were tested regarding their efficiency in collecting airborne particles and grass pollen allergens from outdoor air. Grass pollen allergen and particle number concentrations were measured before and after the filters, enabling collection efficiency calculations. Simultaneously, the size distribution of grass pollen allergens was measured in outdoor air using a cascade impactor. The study confirms previous indications that pollen allergens occur in the outdoor air as particles much smaller than pollen grains, and can penetrate ventilation filters to a larger extent than might be expected. The initially high collection efficiency of synthetic, electrostatically charged filters declined significantly with time of use (dust load), whereas glass fiber filters showed steady performance. A slight tendency for pollen allergenic matter to penetrate ventilation filters more than other airborne particles was noted, but no difference in the response to electrostatic charge of filters could be seen.
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- Olstrup, Henrik, et al.
(författare)
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A Multi-Pollutant Air Quality Health Index (AQHI) Based on Short-Term Respiratory Effects in Stockholm, Sweden
- 2019
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- In this study, an Air Quality Health Index (AQHI) for Stockholm is introduced as a tool to capture the combined effects associated with multi-pollutant exposure. Public information regarding the expected health risks associated with current or forecasted concentrations of pollutants and pollen can be very useful for sensitive persons when planning their outdoor activities. For interventions, it can also be important to know the contribution from pollen and the specific air pollutants, judged to cause the risk. The AQHI is based on an epidemiological analysis of asthma emergency department visits (AEDV) and urban background concentrations of NOx, O-3, PM10 and birch pollen in Stockholm during 2001-2005. This analysis showed per 10 mu gm(-3) increase in the mean of same day and yesterday an increase in AEDV of 0.5% (95% CI: -1.2-2.2), 0.3% (95% CI: -1.4-2.0) and 2.5% (95% CI: 0.3-4.8) for NOx, O-3 and PM10, respectively. For birch pollen, the AEDV increased with 0.26% (95% CI: 0.18-0.34) for 10 pollen grainsm(-3). In comparison with the coefficients in a meta-analysis, the mean values of the coefficients obtained in Stockholm are smaller. The mean value of the risk increase associated with PM10 is somewhat smaller than the mean value of the meta-coefficient, while for O-3, it is less than one fifth of the meta-coefficient. We have not found any meta-coefficient using NOx as an indicator of AEDV, but compared to the mean value associated with NO2, our value of NOx is less than half as large. The AQHI is expressed as the predicted percentage increase in AEDV without any threshold level. When comparing the relative contribution of each pollutant to the total AQHI, based on monthly averages concentrations during the period 2015-2017, there is a tangible pattern. The AQHI increase associated with NOx exhibits a relatively even distribution throughout the year, but with a clear decrease during the summer months due to less traffic. O-3 contributes to an increase in AQHI during the spring. For PM10, there is a significant increase during early spring associated with increased suspension of road dust. For birch pollen, there is a remarkable peak during the late spring and early summer during the flowering period. Based on monthly averages, the total AQHI during 2015-2017 varies between 4 and 9%, but with a peak value of almost 16% during the birch pollen season in the spring 2016. Based on daily mean values, the most important risk contribution during the study period is from PM10 with 3.1%, followed by O-3 with 2.0%.
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- Ritenberga, O., et al.
(författare)
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A statistical model for predicting the inter-annual variability of birch pollen abundance in Northern and North-Eastern Europe
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 615, s. 228-239
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Tidskriftsartikel (refereegranskat)abstract
- The paper suggests a methodology for predicting next-year seasonal pollen index (SPI, a sum of daily-mean pollen concentrations) over large regions and demonstrates its performance for birch in Northern and North-Eastern Europe. A statistical model is constructed using meteorological, geophysical and biological characteristics of the previous year). A cluster analysis of multi-annual data of European Aeroallergen Network (EAN) revealed several large regions in Europe, where the observed SPI exhibits similar patterns of the multi-annual variability. We built the model for the northern cluster of stations, which covers Finland, Sweden, Baltic States, part of Belarus, and, probably, Russia and Norway, where the lack of data did not allow for conclusive analysis. The constructed model was capable of predicting the SPI with correlation coefficient reaching up to 0.9 for some stations, odds ratio is infinitely high for 50% of sites inside the region and the fraction of prediction falling within factor of 2 from observations, stays within 40–70%. In particular, model successfully reproduced both the bi-annual cycle of the SPI and years when this cycle breaks down. © 2017 Elsevier B.V.
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- Verstraeten, A., et al.
(författare)
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Effects of tree pollen on throughfall element fluxes in European forests
- 2023
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Ingår i: Biogeochemistry. - Göteborg : Springer. - 0168-2563 .- 1573-515X. ; 165:3, s. 311-325
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Tidskriftsartikel (refereegranskat)abstract
- The effects of tree pollen on precipitation chemistry are not fully understood and this can lead to misinterpretations of element deposition in European forests. We investigated the relationship between forest throughfall (TF) element fluxes and the Seasonal Pollen Integral (SPIn) using linear mixed-effects modelling (LME). TF was measured in 1990-2018 during the main pollen season (MPS, arbitrary two months) in 61 managed, mostly pure, even-aged Fagus, Quercus, Pinus, and Picea stands which are part of the ICP Forests Level II network. The SPIn for the dominant tree genus was observed at 56 aerobiological monitoring stations in nearby cities. The net contribution of pollen was estimated as the TF flux in the MPS minus the fluxes in the preceding and succeeding months. In stands of Fagus and Picea, two genera that do not form large amounts of flowers every year, TF fluxes of potassium (K+), ammonium-nitrogen (NH4+-N), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) showed a positive relationship with SPIn. However- for Fagus- a negative relationship was found between TF nitrate-nitrogen (NO3--N) fluxes and SPIn. For Quercus and Pinus, two genera producing many flowers each year, SPIn displayed limited variability and no clear association with TF element fluxes. Overall, pollen contributed on average 4.1-10.6% of the annual TF fluxes of K+ > DOC > DON > NH4+--N with the highest contribution in Quercus > Fagus > Pinus > Picea stands. Tree pollen appears to affect TF inorganic nitrogen fluxes both qualitatively and quantitatively, acting as a source of NH4+--N and a sink of NO3--N. Pollen appears to play a more complex role in nutrient cycling than previously thought.
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