House dust mites in university dormitories

As no published data was available, dust was collected from 102 university student dormitory rooms and 33 were selected on a random basis for analysis. Mean dust per dormitory room was 4.47 g of coarse, 0.96 g of fine, and a 24-hour sedimented volume of fine dust of 6.90 mL. The mean number of mites was 63/g of coarse dust, and 240/g and 36/mL of fine dust. They were identified as D. pteronyssinus (D.p.), 81.9%; D. farinae, 11.2%; and Cheyletus, 4.7%. Fifteen samples from homes were controls. Mean values were 0.60 g of coarse dust, and 0.20 g and 2.3 mL of fine dust. Mites numbered 985/g of coarse, and 3409/g and 244/mL of fine dust. They were D.p., 87.2%; D. farinae, 3.0%; Cheyletus, 3.7%; and Euroglyphus, 1.6%. Differences between dormitories and homes in amount of dust and number of mites were significant at P less than .001. Dust and mites were significantly less in dormitories with linoleum than those with carpets (P less than .05 and .01, respectively). In conclusion, university dormitories have significantly less mites than homes despite a greater amount of dust harvested.