Airborne study of grass allergen (Lol p 1) in different-sized particles

The Poaceae family is considered one of the main causes of pollen allergy in industrialized countries. The aim of this study is to establish the dynamics of the Poaceae allergens and determine their distribution in the different-sized particles in the atmosphere.

The air of Granada (southern Spain) was sampled during the pollination period of Poaceae using a cascade impactor and a Hirst-type volumetric collector simultaneously. The sampled airborne allergens were analyzed by indirect ELISA and field emission scanning electron microscopy. Airborne pollen was evaluated with the Spanish Aerobiological Network methodology.

Poaceae pollen and allergenic activity have parallel dynamics during the period of maximum pollination, which is reflected in the positive correlations between the 2 variables. In addition, the highest Lol p 1 concentrations were recorded in particle sizes lower than 3.3 mum (stage 4-F). The Spearman correlation test showed that airborne allergens are not dependent on meteorological factors, such as humidity, wind direction or sunshine, however, Lol p 1 allergen correlated positively with Poaceae pollen.

The results of the present study confirm that the Lol p 1 allergen is detected more frequently with pollutants than with coarse particles with similar dynamics and a positive correlation between airborne pollen and aeroallergens. Moreover, Lol p 1 is released in stable weather conditions without large changes in humidity or temperature.