TY - JOUR
T1 - Exposure to green space and pollen allergy symptom severity
T2 - A case-crossover study in Belgium
AU - Stas, Michiel
AU - Aerts, Raf
AU - Hendrickx, Marijke
AU - Delcloo, Andy
AU - Dendoncker, Nicolas
AU - Dujardin, Sebastien
AU - Linard, Catherine
AU - Nawrot, Tim
AU - Van Nieuwenhuyse, An
AU - Aerts, Jean Marie
AU - Van Orshoven, Jos
AU - Somers, Ben
N1 - Funding Information:
This study was carried out in the framework of the RespirIT project, which has been supported by a grant from the Belgian Science Policy Office BELSPO (grant nr. BR/154/A1/RespirIT ). The researchers would like to thank Dr. Evi Dons and MSc. (Ir.) Matthias Defoort for their contributions to the development of the dynamic exposure approach.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/8/10
Y1 - 2021/8/10
N2 - Background: The prevalence of pollen allergy has increased due to urbanization, climate change and air pollution. The effects of green space and air pollution on respiratory health of pollen allergy patients are complex and best studied in spatio-temporal detail. Methods: We tracked 144 adults sensitized to Betulaceae pollen during the tree pollen season (January–May) of 2017 and 2018 and assessed their spatio-temporal exposure to green space, allergenic trees, air pollutants and birch pollen. Participants reported daily symptom severity scores. We extracted 404 case days with high symptom severity scores and matched these to 404 control days. The data were analyzed using conditional logistic regression with a 1:1 case-crossover design. Results: Case days were associated with exposure to birch pollen concentration (100 grains/m3) [adjusted odds ratio 1.045 and 95% confidence interval (1.014–1.078)], O3 concentration (10 μg/m3) [1.504 (1.281–1.766)] and PM10 concentration (10 μg/m3) [1.255 (1.007–1.565)] on the day of the severe allergy event and with the cumulative exposure of one and two days before. Exposure to grass cover (10% area fraction) [0.655 (0.446–0.960)], forest cover (10% area fraction) [0.543 (0.303–0.973)] and density of Alnus (10%) [0.622 (0.411–0.942)] were protective for severe allergy, but only on the day of the severe allergy event. Increased densities of Betula trees (10%) were a risk factor [unadjusted OR: 2.014 (1.162–3.490)]. Conclusion: Exposure to green space may mitigate tree pollen allergy symptom severity but only when the density of allergenic trees is low. Air pollutants contribute to more severe allergy symptoms. Spatio-temporal tracking allows for a more realistic exposure assessment.
AB - Background: The prevalence of pollen allergy has increased due to urbanization, climate change and air pollution. The effects of green space and air pollution on respiratory health of pollen allergy patients are complex and best studied in spatio-temporal detail. Methods: We tracked 144 adults sensitized to Betulaceae pollen during the tree pollen season (January–May) of 2017 and 2018 and assessed their spatio-temporal exposure to green space, allergenic trees, air pollutants and birch pollen. Participants reported daily symptom severity scores. We extracted 404 case days with high symptom severity scores and matched these to 404 control days. The data were analyzed using conditional logistic regression with a 1:1 case-crossover design. Results: Case days were associated with exposure to birch pollen concentration (100 grains/m3) [adjusted odds ratio 1.045 and 95% confidence interval (1.014–1.078)], O3 concentration (10 μg/m3) [1.504 (1.281–1.766)] and PM10 concentration (10 μg/m3) [1.255 (1.007–1.565)] on the day of the severe allergy event and with the cumulative exposure of one and two days before. Exposure to grass cover (10% area fraction) [0.655 (0.446–0.960)], forest cover (10% area fraction) [0.543 (0.303–0.973)] and density of Alnus (10%) [0.622 (0.411–0.942)] were protective for severe allergy, but only on the day of the severe allergy event. Increased densities of Betula trees (10%) were a risk factor [unadjusted OR: 2.014 (1.162–3.490)]. Conclusion: Exposure to green space may mitigate tree pollen allergy symptom severity but only when the density of allergenic trees is low. Air pollutants contribute to more severe allergy symptoms. Spatio-temporal tracking allows for a more realistic exposure assessment.
KW - Air pollution
KW - Allergic rhinitis
KW - Biodiversity
KW - Birch pollen allergy
KW - Personal exposure
UR - http://www.scopus.com/inward/record.url?scp=85104881421&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.146682
DO - 10.1016/j.scitotenv.2021.146682
M3 - Article
C2 - 33812114
AN - SCOPUS:85104881421
SN - 0048-9697
VL - 781
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 146682
ER -