Electrostatic Allergen Control

The presence of allergens in the domestic environment has been linked to the development and elicitation of symptoms of atopic asthma. Although a number of techniques exist to reduce indoor allergens, attempts over the last thirty years have been largely unsuccessful. The objective of this present investigation was to determine whether corona discharge, the process used in air ionisers, could destroy the major household allergens of the Dermatophagoides house dust mite Der p1, Der f1, Der p2 and the major domestic cat allergen, Fel d1. Using a simple point-to-plane corona apparatus of fixed inter-electrode distance and point radius, the effects of corona discharge were investigated on the allergens mentioned above. The results have shown that a specific number of allergen molecules are destroyed per unit exposure to corona discharge. This corona-destruction of allergens increased exponentially with both time and corona current until a plateau in the maximum percentage reduction in concentration was attained. Fel d1 was the most susceptible to destruction by negative corona, which led to a percentage reduction in concentration of 100% after 180 minutes at 25mA corona current. Dermatophagoides allergens experienced approximately similar reductions to each other. Fel d1, unlike the mite allergens tested, was not affected by positive corona. The effect of corona on Der p1 was not due to the corona product molecular ozone, or due to the presence of aluminium oxides on the planar electrodes. Der p1 was not destroyed under an atmosphere of 2.4% relative humidity using negative corona regimes, but was destroyed when subjected to positive corona under these conditions. The lack of renaturing after exposure to corona discharge and other results suggest that irreversible reactions occur between the corona products and the primary structure of the protein.