title: [A relationship between birch pollen and meteorological factors during the past four years and pollen survey in Sapporo in 1997].
abstract: It is well known that grass pollinosis has been the most representative pollinosis in Hokkaido prefecture, Japan, However, it is also well known that birch (Japanese white birch, Betula platyphylla var. japonica) pollinosis is gradually increasing, which is marked especially in Sapporo and its neighborhood. We analyzed a relationship between the birch pollen count and meteorological factors statistically. Moreover, the principal airborne pollen counts in Sapporo in 1997 were assessed and compared with the previous pollen data. As a results of this study, it was showed a close relationship between the annual amounts of birch pollen and meterological factors of the year before, especially in May and June might be important. Moreover, there is a strong negative correlation between the birch pollen count and humidity, which seems to affect bringing up flower buds. As for the principal airborne pollen counts, some kinds of tree pollen, including birch pollen, were observed from the end of March, followed by grass (Gramineae) pollen in June and mugwort (Artemisia) pollen from the end of August, respectively. The annual amounts of grass pollen showed a decreasing trend.
authors.affiliation: Department of Otolaryngology, School of Medicine, Sapporo Medical University.
authors.forename: H
authors.initials: H
authors.lastname: Ogasawara
authors.forename: A
authors.initials: A
authors.lastname: Kataura
authors.forename: K
authors.initials: K
authors.lastname: Asakura
authors.forename: T
authors.initials: T
authors.lastname: Matsui
mesh_terms: D000397:Air Pollution; D007564:Japan; D008685:Meteorological Concepts; D011058:Pollen; D012621:Seasons; D014197:Trees