Aerobiology of Artemisia airborne pollen in Murcia (SE Spain) and its relationship with weather variables: annual and intradiurnal variations for three different species. Wind vectors as a tool in determining pollen origin.

Detailed results from a 2-year survey of airborne pollen concentrations of Artemisia in Murcia are presented. Three consecutive pollen seasons of Artemisia occurring each year, related to three different species (A. campestris, A. herba-alba and A. barrelieri), were observed. A winter blooming of Artemisia could explain the incidence of subsequent pollinosis in the Murcia area. With regard to meteorological parameters, mathematical analyses showed relationships between daily pollen concentrations of Artemisia in summer-autumn and precipitations that occurred 6-8 weeks before. The cumulative percentage of insolation from 1 March seemed to be related to blooming onsets. Once pollination has begun, meteorological factors do not seem to influence pollen concentrations significantly. Intradiurnal patterns of pollen concentrations were similar for late summer and winter species (A. campestris and A. barrelieri). During autumn blooming (A. herba-alba), the intradiurnal pattern was particularly erratic. Theoretical values of wind run were obtained for each pollen season by the graphical sum of hourly wind vectors. When theoretical wind run was mapped onto the vegetation pattern, supposed pollen source locations were obtained for each hour. By comparing supposed hourly pollen origins with the intradiurnal patterns of pollen concentrations, it can be seen that this simple model explains variations in mean pollen concentrations throughout the day.

Incidence of Alternaria spores in the atmosphere of Murcia (SE Spain). Seasonal, monthly and intradiurnal variations.

Variation in Alternaria spores in the atmosphere of Murcia (SE Spain) were studied for 2 years. Using a Burkard volumetric sampler located about 19 m above ground level, spores were collected and counted hourly by light microscopy. The results suggest that species of Alternaria are present in the atmosphere of Murcia every day throughout the year. Mean daily concentration of Alternaria was 25 spores/m3. Seasonal variations showed the lowest concentrations during winter and the highest in autumn. In the monthly pattern two peaks were observed every year: the first in about May-June and the second occurring in October. In the intradiurnal variations, maximum concentrations were observed between 5:00-6:00 p.m. (Spanish official time). The variation of Alternaria spores in the atmosphere in Murcia seems to be related to different factors throughout the year.