The accumulation of dust mite allergens on mattresses made of different kinds of materials

Background: Different mattress materials may affect the accumulation of allergens. Objective: To compare the amount of group 1 dust mite allergens (Der p1 + Der f1) on mattresses made of different kinds of materials before and after use. Methods: Sixty new mattresses made of kapok, synthetic fiber, coconut fiber and sponge-like polyurethane, were placed in the house officers' dormitory at Siriraj hospital, Thailand. The dust samples were collected before (0), 1, 2, 3, 6, 9 and 12 months after the mattresses were used. Group 1 dust mite allergens were analyzed using two-site monoclonal antibody ELISA. Results: Der f1 made up 86.7 % of group 1 allergens found in the matress dust. After the 2^nd month, only the mean level in sponge-like polyurethane mattress was under 2 μg/g dust (sensitized level). At the 6^th month, the mean levels were 13.1 in coconut, 21.7 in kapok and 17.3 μg/g dust in synthetic fiber, all of which were more than 10 μg/g dust (symptomatic level). At the 9^th month, the level in sponge-like polyurethane mattress was increased to 11.2 μg/g. At 12^th month the level in coconut fiber, sponge-like polyurethane synthetic fiber and kapok mattresses were 20.2, 22.4, 28.9 and 32.2 μg/g dust respectively. Conclusions: The accumulation rate in kapok and synthetic mattresses was significantly higher than coconut and sponge-like polyurethane mattresses. The mean level of group 1 mite allergens exceeded 10 μg/g dust after the 6^th month of use in coconut fiber, kapok and synthetic fiber and at the 9^th month in sponge-like polyurethane mattress.