Clinical relevance of spore and pollen counts.

Many people with allergies monitor daily pollen and spore counts with the belief that they can act on that information to improve their health. Because many factors can affect personal exposure, the value of community-wide counts for an individual is questionable. These factors include the presence of local pollen and spore sources, diurnal variations, weather effects, air pollution, and a particle-free bioaerosol. To take advantage of bioparticulate counts, the public needs to be informed about their meaning and factors that can influence personal exposure.