BACKGROUND: Two important indoor pollutants are house dust mite, whose concentration is particularly high within the mattress, and NO2, which either originates from outdoor pollution or is produced by cooking devices.
AIMS: To evaluate whether allergies and respiratory symptoms in young adults are affected by the indoor levels of house dust mites and NO2.
STUDY DESIGN: In about 25 European centres, home visits were performed in dwellings of people who had undergone lung function tests and skin prick tests. During the visit, dust samples were taken from the mattress to measure the concentration of dust mite and NO2 samplers are open inside and outside the kitchen window to measure NO2 concentration.