AN ASSESSMENT OF THE Ambrosia L. POLLEN THREAT AT A REGIONAL SCALE USING THE EXAMPLE

The investigation of Ambrosia pollen counts in the air of Sosnowiec was carried out from 1998 to 2010 by means of the volumetric method. The pollen season which was determined by means of the 98 % method started at the end of July and the beginning of August and lasted until the end of October. The hi-ghest Ambrosia pollen count was recorded in 1999 (222 grains x m-3) and the lowest in 2001 (18 grains x m-3). It was stated that the daily count of pollen grains depended on the wind direction and maximum air temperature. The strongest correlations were found with maximum temperature and with a wind direction from the south east. A high negative correlation coefficient was found between the frequency of inflows of air masses from the west and the annual total of pollen grains and the value of the maximum daily count. The closest sites of Ambrosia L. are at a distance of 25–40 kilometres from the sampling point. Signifi-cant correlations with the frequency of inflow of air masses can support the conclusion that Ambrosia pollen grains recorded in Sosnowiec were most probably carried not only from local so-urces but also, at least in part, from distant places