An aerobiological study of Urticaceae pollen in the city of Granada (S. Spain): correlation with meteorological parameters

An aerobiological study was made of Urticaceae pollen in the city of Granad a, relating the mean values of the daily counts to meteorological parameter s. Sampling was carried out with a Burkard seven-day-recording spore trap f rom October 1992 to September 1997. This pollen type has an extremely long main pollen season (MPS), with maximum counts in (January) February, March and April, causing numerous cases of human pollinosis throughout the entire Mediterranean region, including Granada. A highly constant intradiurnal va riation pattern was obtained showing that the maximum peaks usually occur b etween 12.00 and 20.00. According to Spearman's correlation coefficient, du ring the pre-peak period the parameters which have the greatest effect on t he levels of this type of pollen are daily and accumulated temperature and sunshine, accumulated rainfall, and wind direction from the third quadrant, during the post-peak period these same variables presented significantly n egative coefficients. Daily rainfall and relative humidity presented negati ve coefficients during the entire MPS. The maximum daily temperature was th e variable which provided the closest match with the theoretical predictive pattern presented here.