Dust from carpeted and smooth floors. IV. Solid material, proteins and allergens collected in the different filter stages of vacuum cleaners after ten days of use in schools.
The accumulation of dust, proteins and allergens from alder, birch, timothy, cat, dog, mite, hen egg white, codfish and mould in schools was investigated by analysing the content of vacuum cleaners after 10 days of use. The main goals were to compare the dust accumulation on carpeted and smooth floors and to estimate to what degree the three vacuum cleaner filter stages (i.e. the disposable bag, the main filter and the microfilter) collected dust, proteins and allergens. Carpeted floors accumulated more dust, proteins and allergens per unit area than smooth floors. Histamine release studies of some of the dust extracts showed that the dust from carpeted floors released histamine from passively sensitized basophils at concentrations for which dust from smooth floors gave low or no histamine release. The analyses showed that most of the dust, proteins and allergens were retained in the dust bags. Less than 1% of the vacuumed material had accumulated in the main filters, which, according to the manufacturer, detain 99.5% of particles greater than 2 microns. By the use of a scanning electron microscope (SEM), particle deposits were observed in the microfilters. These deposits, which represented less than 0.1% of the total mass, showed no significant allergenic activity. Thus, for the field conditions of this study, the microfilters were not needed for cleaning the exit air of allergens, although they were useful for removing fine (less than 2 microns) particles.
Dybendal
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Allergy Research Group, Laboratory of Clinical Biochemistry, University Hospital, Haukeland sykehus, Norway.
Wedberg
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WC
Elsayed
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D000393:Air Pollutants / Q000032:analysis*; D000485:Allergens / Q000032:analysis*; D004391:Dust / Q000032:analysis*; D005430:Floors and Floorcoverings; D005500:Follow-Up Studies; D006636:Histamine Release; D006796:Household Work; D006801:Humans; D008855:Microscopy, Electron, Scanning; D011058:Pollen; D011852:Radioallergosorbent Test; D012574:Schools
D000393:Air Pollutants; D000485:Allergens; D004391:Dust