Preselection area of a representative aerobiological sampling station of a tropical valley.

In order to search an uniform criteria for sampling aerobiological particles, three sites were selected along the valley of Caracas. The distribution of vegetation, topographical and meteorological parameters were monitored. Pollen and spores were collected at each site during 24 hr at 6 min-intervals with a Rotorod sampler. Pollen counts were similar in all sites and much less abundant than spores. Cladosporium was the most abundant spore and grass pollen represented more than 50% of the pollen grains. Results showed that the three sites could be selected as suitable sampling area for airborne pollen and spores. Nevertheless, we recommend the selection of the most accessible and central site for a long-term sampling.