The vertical distribution of house dust mite allergen in carpet and the effect of dry vacuum cleaning

• Published in: International journal of hygiene and environmental health 2007-01, Vol.210 (1), p.43-50
• Main Authors: Sercombe, Jason K., Liu-Brennan, Damien, Causer, Simon M., Tovey, Euan R.
• Format: Article
• Language: English
• Subjects: Air. Soil. Water. Waste. Feeding; Allergen; Allergens - analysis; Animals; Antigens, Dermatophagoides - analysis; Arthropod Proteins; Biological and medical sciences; Carpet; Cysteine Endopeptidases; Der p 1; Dermatophagoides; Dermatophagoides pteronyssinus; Dust - analysis; Environment. Living conditions; Floors and Floorcoverings; House dust mite; Household Articles - instrumentation; Housekeeping - methods; Medical sciences; Miscellaneous; Public health. Hygiene; Public health. Hygiene-occupational medicine; Toxicology; Vacuum cleaning
• ISSN: 1438-4639; 1618-131X
• DOI: 10.1016/j.ijheh.2006.06.006

Carpets are large reservoirs of the dust mite allergen Der p 1. The effect of vacuum cleaning on the distribution of Der p 1 in carpets is poorly understood. Samples were cut from 7 used household carpets, all over 5 years of age. From each carpet, 10 samples were left untreated, 10 vacuumed with an upright vacuum cleaner, and 10 vacuumed with a canister vacuum cleaner. Each section was then cut into 3 horizontal layers: the top 2 mm, the remainder of the carpet pile, and the carpet base. The mass of Der p 1 as a proportion of carpet volume was then determined. The concentrations of Der p 1 in each depth layer varied considerably between the 7 untreated carpets. In the top layer, Der p 1 concentrations were (median; 25th–75th percentiles): 41.9; 28.3–92.6 pg/mm 3. For the middle layer they were similar (38.1; 22.4–108.5 pg/mm 3), and for the carpet base, higher (212.4; 98.8–456.2 pg/mm 3). In most cases, cleaning using either type of vacuum cleaner resulted in no significant reduction in allergen concentration throughout all depth layers. A subset of carpets showed an apparent increase in Der p 1 concentration in one or more layers following vacuum cleaning. In all tests Der p 1 was collected in the vacuum cleaners’ filter bags. The depth-distribution of Der p 1 differs widely amongst used carpets. Vacuum cleaning changes the distribution of Der p 1 within such carpets but does not necessarily result in a reduction in the overall content.