Over 80% of weekday time is spent indoors and the air quality of this environment may affect the incidence of symptoms in allergy sufferers. However, indoor/outdoor measurements have been jointly considered only in a few studies.

The objective of this paper is to analyse indoor/outdoor biological and non-biological particle content togeher with other factors affecting the severity of symptoms during working periods in an Aerobiology Lab during the most troublesome period of the year for allergy sufferers. For this purpose, indoor/outdoor air samples were taken using standard portable particle traps at the National Coordinating Centre of the Spanish Aerobiology Network, University of Cordoba. The analysis differentiated between biological and nonbiological material, and the allergy symptoms suffered by workers were quantified and correlated accordingly. An inventory of the incoming and outgoing sources of emissions was done in order to identify agravating co-factors.

The results showed that since there was very little air movement between indoors and outdoors, there was a significant difference in the amount of biological material present in the two areas. The presence of some indoor source of emissions, such as the Plant Collections property of the Department, the Air Conditioned System and the volatile compounds of the copying machine was responsible of high particle content. External factors such as weather conditions or human activities contributed exacerbating symptoms.

As Conclusion, the knowledge of airborne biological particle content could be a useful tool in minimising allergy symptoms when environmental conditions render them inevitable.

Keywords: Occupational Allergy, Aerobiology, indoor/outdoor particle content, air quality, pollen allergy, indoor environment, allergenic activity, pollinosis symptoms, asthma