SURVEY ON JAPANESE CEDAR POLLEN DISPERSION IN THE CITY OF OJIYA IN NIIGATA PREFECTURE AND ITS PREDICTION

Abstract

This is a report on cedar pollen dispersion in the city of Ojiya in Niigata Prefecture from 2002 to 2007. We found that the total amount of cedar pollen dispersed in this region was related to the number of daylight hours during the months between late July to early/mid-August of the previous year. It was also ascertained that in this region, if the maximum daily temperature exceeded 10°C for the first time that year before the cedar pollen had dispersed, then the cedar pollen began dispersing 1) either on that day or in the two days before or after that day, or 2) approximately two weeks or more after that day. We believe that the occurrence of 1) or 2) roughly depends on the accumulated value of the maximum temperature from January 1 to the day when the maximum temperature exceeded 10°C. Therefore, we believe that establishing the day on which the maximum temperature exceeds 10°C for the first time in the year as the day on which treatment regimens must be begun for patients with cedar pollen allergy would be useful for both cedar pollinosis patients and medical therapists in this region.