Abstract
Sofas are known to be contaminated with mites, but no data exist on the amount of the mite allergen Der 1 detected in sofas in Japan. In October 2017, the authors collected house dust from sofas and floors in five homes in the Kanto region and measured the amount of Der 1 in the dust. The geometric mean of Der 1 in the sofa dust was 27.8 μg/g, and that in the floor dust was 2.6 μg/g. Four of the five sofas had Der 1 levels exceeding 10 μg/g dust, which is considered the threshold for an increased risk of asthma, while the remaining one exceeded 2 μg/g dust, which is considered the threshold for an increased risk of mite sensitization.
