[Artemisia monosperma of the coastal plain as an allergen source in Jerusalem]

The possibility that pollen grains of Artemisia monosperma (AM) are transported to Jerusalem from their native habitat along the coastal plain was investigated. Air-borne pollen grains were sampled in the early autumn of 1989 with a Rotorod pollen sampler. During that period only 1 of the 4 species of AM in Israel, A. monosperma, was flowering. The sampling day was typical for the late summer, with a light NW breeze. Sampling was done simultaneously in 3 sites: Tel Aviv, Carmei Yosef and Jerusalem. The greatest concentration of pollen in Tel Aviv was found during the morning hours and decreased during the course of the day. Pollen counts in Carmei Yosef reached a maximum at 11:00 a.m. A substantial number of air-borne AM pollen was recorded in Jerusalem, with a daily peak at 1:00 p.m. Such results fit well the distribution pattern of the pollen as expected from the recorded wind velocity and direction. They also agree well with the data for transportation of other air pollutants from the coastal plain to Jerusalem. Apparently AM pollen is transported to Jerusalem over distances of many tens of kilometers, even on days with light winds. Therefore, such pollen may constitute an allergenic factor in Jerusalem in the autumn. It is reasonable to assume that transportation of pollens of other coastal plants follows a similar pattern.