S E K Müller-Rompa1, I Markevych2,3, A J Hose1, G Loss1,4, I M Wouters5, J Genuneit6, C Braun-Fahrländer7,8, E Horak9, A Boznanski10, D Heederik5, E von Mutius1,11,12, J Heinrich2, M J Ege1,11. 1. Dr von Hauner Children's Hospital, LMU Munich, Munich, Germany. 2. Institute of Epidemiology I, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany. 3. Institute for Occupational, Social, and Environmental Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany. 4. Departments of Pediatrics and Computer Science & Engineering, University of California at San Diego, San Diego, CA, USA. 5. Division Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands. 6. Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany. 7. Swiss Tropical and Public Health Institute Basel, Basel, Switzerland. 8. University of Basel, Basel, Switzerland. 9. Innsbruck Medical University, Innsbruck, Austria. 10. Wroclaw Medical University, Wroclaw, Poland. 11. Comprehensive Pneumology Center Munich (CPC-M), Member of the German Center for Lung Research, Munich, Germany. 12. Institute for Asthma and Allergy Prevention, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.
Abstract
BACKGROUND: The highly consistent association of growing up on a farm with a reduced asthma risk has so far been attributed to direct farm exposure. In contrast, geographic determinants of the larger environment have never been assessed. In this study, the effects of proximity to farms and environmental variables in relation to the residential address on asthma and atopy were assessed. METHODS: Addresses of 2265 children of the Bavarian arm of the GABRIELA study were converted into geocodes. Proximity to the nearest cow farm was calculated, and environmental characteristics were derived from satellite data or terrestrial monitoring. Bacterial diversity in mattress dust samples was assessed in 501 children by sequencing of the 16S rRNA amplicons. Logistic regression models were used to calculate associations between outcomes and exposure variables. RESULTS: Asthma and atopy were inversely associated with the presence of a farm within a radius of maximum 100 m. The environmental variables greenness, tree cover, soil sealing, altitude, air pollution differed not only between farm and non-farm children but also between farm children with and without another farm nearby. The latter distinction revealed strong associations with characteristics of traditional farms including a broader diversity of microbial exposure, which mainly contributed to the protective effect on asthma. In non-farm children, the protective effect of a farm nearby was completely explained by consumption of farm milk. CONCLUSIONS: Clustering of farms within a neighborhood of 100 m is strongly associated with the protective effect on asthma and may represent a more traditional style of farming with broader microbial exposure.
BACKGROUND: The highly consistent association of growing up on a farm with a reduced asthma risk has so far been attributed to direct farm exposure. In contrast, geographic determinants of the larger environment have never been assessed. In this study, the effects of proximity to farms and environmental variables in relation to the residential address on asthma and atopy were assessed. METHODS: Addresses of 2265 children of the Bavarian arm of the GABRIELA study were converted into geocodes. Proximity to the nearest cow farm was calculated, and environmental characteristics were derived from satellite data or terrestrial monitoring. Bacterial diversity in mattress dust samples was assessed in 501 children by sequencing of the 16S rRNA amplicons. Logistic regression models were used to calculate associations between outcomes and exposure variables. RESULTS:Asthma and atopy were inversely associated with the presence of a farm within a radius of maximum 100 m. The environmental variables greenness, tree cover, soil sealing, altitude, air pollution differed not only between farm and non-farm children but also between farm children with and without another farm nearby. The latter distinction revealed strong associations with characteristics of traditional farms including a broader diversity of microbial exposure, which mainly contributed to the protective effect on asthma. In non-farm children, the protective effect of a farm nearby was completely explained by consumption of farm milk. CONCLUSIONS: Clustering of farms within a neighborhood of 100 m is strongly associated with the protective effect on asthma and may represent a more traditional style of farming with broader microbial exposure.
Authors: Le Duc Huy Ta; Carina Jing Xuan Tay; Christophe Lay; Paola Florez de Sessions; Cheryl Pei Ting Tan; Michelle Jia Yu Tay; Hui Xing Lau; Atiqa Binte Zulkifli; Gaik Chin Yap; Elizabeth Huiwen Tham; Eliza Xin Pei Ho; Anne Eng Neo Goh; Keith M Godfrey; Johan G Eriksson; Jan Knol; Peter D Gluckman; Yap Seng Chong; Jerry Kok Yen Chan; Kok Hian Tan; Kok Wee Chong; Si Hui Goh; Zai Ru Cheng; Bee Wah Lee; Lynette Pei-Chi Shek; Evelyn Xiu Ling Loo Journal: Environ Microbiol Date: 2021-08-12 Impact factor: 5.476