The home environment of junior high school students in Hyogo, Japan - Associations with asthma, respiratory health and reported allergies

Associations between home environment factors and respiratory symptoms, and reported allergies among junior high school students in Kobe, Japan (N=1048) were investigated in the present study. These were mutually adjusted for age, sex, type of school (private/local) and their significant exposures to the environment. Totally 13.4% of students reported to have doctor's diagnosed asthma, 9.9% had wheeze and 50.1% had attacks of daytime breathlessness during past 12 months, 25.7% of students reported that they had pollen allergy, 8.8% had cat allergy and 6.1% had dog allergy. Totally 29.4% of students were living in a wooden house and during past 12 months, 18% of students reported that their homes had signs of dampness, 38.2% of homes had window condensation in winter and 7.8% of homes had indoor painting. Window condensation was associated with wheeze (odds ratio (OR)=1.54; 95% confidence interval (CI) 1.01-2.34), daytime breathlessness (OR=2.02; 95% CI 1.56-2.63), airway infection during past 12 months (OR=1.66; 95% CI 1.17-2.37), cat allergy (OR=1.63; 95% CI 1.05-2.54); mould allergy (OR=1.84; 95%CI 1.08-3.12) and pollen allergy (OR=1.54; 95% CI 1.15-2.06). Recent indoor painting was associated with daytime breathlessness (OR 1.83; 95% CI 1.12-3.00), dog allergy (OR=2.23; 95% CI 1.02-4.85) and mould allergy (OR=2.43; 95% CI 1.14-5.17). Living in a wooden house was associated with dog allergy (OR=2.17; 95% CI 1.18-4.00) and mould allergy (OR=1.98; 95% CI 1.04-3.76). In conclusion, in Japanese homes, the window condensation in winter, recent indoor painting and living in a wooden house could contribute to the increased risk of respiratory symptoms and allergies for young Japanese school children.