Acknowledgements
We would like to thank all the volunteers who participated in the study.
We also thank the Aerobiology Unit of the University of Turku for
lending the Burkard samplers. We thank Dr. Behzad Heibati and Dr. Mari
Kauhaniemi (FMI) for their assistance in processing the map images.
This work was supported by the Research Council for Health, the Academy
of Finland [grant numbers 266314, 267675, and 267995 (APTA Consortium)
and 310372 (GLORIA Consortium)], European Union ECHO civil protection
mechanism (EXTREMA, grant number 783180) and the University of Oulu
Strategic Funding. The funders had no role in study design, data
collection or analysis, decision to publish, or preparation of the
manuscript.