Prediction of the Date of Japanese Cedar Pollen Release in Aomori Prefecture

When we treat patients with pollen allergy, we require correct information about pollen release. The total count of pollen and the date of first pollen release are strongly influenced by local weather conditions, so we wanted to predict local pollen release. Patients have degrees of sensitivity to pollen, with symptoms triggered in some cases by only small amounts. Therefore, we wanted to determine the previous dates of first pollen release (A), the first of two consecutive dates when one (count/cm2) or more grains were released (B), and the first of two consecutive dates when ten (count/cm2) or more grains were released (C). Aomori Prefecture has three different weather zones because it is surrounded by three oceans the Sea of Japan, the Pacific Ocean, and Mutsu Bay. We predicted pollen release in the major cities--Aomori, Hirosaki, and Hachinohe. Using nine years (1996-2004) of temperature data for each city from January 1 through February 1, we recorded the number of days in which the daily highest temperature was higher than each of five set temperatures (0 degree C, 1 degree C, 2 degrees C, 3 degrees C, 4 degrees C) up to the dates of A, B, and C. Multiple recordings were made for each year with the initial date of recording staggered at 10-day intervals. We then calculated the standard deviation and the efficient of variation of total days and totals of temperatures over set temperatures. For Aomori, results indicated that A was predicted as day 19 with temperatures over 4 degrees C after January 21. B was day 23 over 4 degrees C after January 21. C was the day 31 with over 4 degrees C after January 21. For Hirosaki, A was expected to be day 26 having temperatures over 0 degrees C after February 1. B was day 21 over 3 degrees C after February 1. C was day 30 over 3 degrees C after January 21. For Hachinohe, A was day 34 with temperatures over 0 degrees C after February 1. B was day 33 over 1 degree C after January 21. C was day 27 over 4 degrees C after January 21. We examined the day of pollen release in 2005.