THE PREVALENCE OF DERMATOPHAGOIDES MITE ALLERGEN IN COLORADO HOMES UTILIZING CENTRAL EVAPORATIVE COOLERS

Objective: The prevalence of mite allergen was studied in homes in which the indoor relative humidity may be increased by use of an evaporative cooler. Methods: Colorado homes in which central evaporative coolers are used and control homes were evaluated. ELISAs with monoclonal antibodies specific for Der p 1 and Der f 1 were performed on dust samples from each home in May and August. Indoor relative humidity and temperatures were recorded daily. Results: May samples did not show significant levels of mite allergen (<2 mu g/gm dust). Of the August samples, 48 of 95 samples from homes with evaporative coolers (50.5%) had levels of Der p 1 and Der f 1 of 2 mu g/gm dust or greater, but only 5 of 95 control samples (5.2%) had levels of 2 mu g/gm dust or greater (p < 0.00001). Twelve of 19 homes with evaporative coolers (63%) were positive for mite allergen. Five of 19 (26%) control homes were positive (p < 0.05). The homes with evaporative coolers had average indoor relative humidity of 51% or greater: control homes had average relative humidity of less than 45%. Conclusion: Altering the indoor environment by raising indoor relative humidity through use of evaporative coolers lends to conditions that may facilitate Dermatophagoides survival.