House-dust-mite allergen (Der p 1) levels in university colleges.

Abstract

In coastal Australia, mean house-dust-mite allergen concentration is 20-40 times higher in homes than in public buildings. Allergen concentrations in university colleges, which share some characteristics of both homes and public buildings, are not known. The study aimed to compare bed mite-allergen concentration in colleges with local homes. Mattress dust was collected from three colleges (n = 60 in each) and local homes (n = 68) during summer. Der p 1 was measured by ELISA. Information was collected on the floor plan of the colleges, cleaning practices, age of building, and orientation of room. Most college mattresses (94%) had Der p 1 concentrations less than the mean of homes in the same climate. The geometric means of Der p 1 in the mattresses of the colleges were as follows: A, 8.9 micrograms Der p 1/g fine dust (95% CI 6.9, 11.5); B, 1.9 (1.5, 2.3); and C, 1.5 (1.2, 2.0), compared to homes, 22.5 (17.6, 28.7). The percentages of college mattresses with less than 2 micrograms/g were 7%, 48%, and 58%, respectively, compared to 4% for homes. Higher Der p 1 concentrations were weakly associated with age of building in college A, and orientation in college B. Der p 1 concentrations were independent of floor level and age of mattress. These findings indicate that low allergen concentrations are achievable without extreme hygiene and cleaning measures in a climate which supports mite proliferation in homes.