Influence of mattress characteristics on house dust mite allergen concentration.
BACKGROUND
Exposure to a high level of house dust mite allergens (HDMAs) is considered as a risk factor for HDM sensitization and development of asthma in genetically disposed people. Mattresses are one of the most important sources of HDMA in people's living environment.


OBJECTIVE
The aim of this study was to evaluate the association between mattress characteristics and HDMA concentrations on mattresses.


METHODS
Dust samples of mattress surfaces were taken to evaluate the level of Der p 1 allergen. All participants filled in a questionnaire about the type of mattress, the type of covering (upper layer) of the mattress, dwelling characteristics and cleaning habits. Humidity and temperature of the bedroom were measured at the time of dust sampling.


RESULTS
One hundred and sixty-eight questionnaires were filled in. Synthetic upper layer of the mattress was associated with a higher level of Der p 1 compared with cotton upper layer (2.6 vs. 0.8 microg/g Der p 1). Moreover, higher relative humidity (RH) was associated with significant higher concentrations and density of Der p 1.


CONCLUSIONS
Two factors were associated with lower levels of Der p 1 found on mattresses, namely: a cotton upper layer of the mattress compared with a layer of synthetic material and lower RH at the time of sampling. As far as we know, the association between type of upper layer and concentration of Der p 1 has not been described before and could lead to the formulation of practical advices in order to reduce HDMA concentrations on mattresses.
Bemt
L
L
Department of General Practice, Research Institute Caphri, Maastricht University, The Netherlands.
Vries
M P
MP
Knapen
L
L
Jansen
M
M
Goossens
M
M
Muris
J W M
JW
Schayck
C P
CP
D016902:Air Pollution, Indoor / Q000009:adverse effects*; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000009:adverse effects / Q000032:analysis*; D060829:Arthropod Proteins; D001249:Asthma / Q000209:etiology*; D001512:Bedding and Linens; D001513:Beds; D032561:Cotton Fiber; D003546:Cysteine Endopeptidases; D004391:Dust; D006801:Humans; D006813:Humidity; D012882:Skin Tests; D013696:Temperature; D014691:Ventilation
D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; D004391:Dust; D003546:Cysteine Endopeptidases; C451162:Dermatophagoides pteronyssinus antigen p 1