The team compared nasal air samples taken before and during vacuum cleaning using both HEPA and non-HEPA vacuum cleaners. They found a small increase in exposure to dust-mite during vacuuming with either type of machine, which was increased when emptying the dust compartments of either.
Lead investigator Dr Robin Gore said: "These vacuum cleaners are marketed to allergy-sufferers on the basis that they reduce a person's exposure to air-borne particles raised from carpeted floors. For allergy sufferers, such particles can trigger asthma attacks. However, we have already found that both HEPA- and non-HEPA vacuum cleaners can actually increase an individual's exposure to particles containing cat allergens.
"These latest findings further suggest that there is no significant advantage to using a HEPA vacuum cleaner to reduce exposure to air-borne particles like dust-mites.
"In combination with our previous work, the study seems to confirm that high-efficiency vacuum cleaners confer no benefits and should not currently be specifically recommended to allergy sufferers as a means of reducing personal exposure to allergens, either by their manufacturers or health professionals."
The study was published in the January 2006 issue of the European Journal of Allergy and Clinical Immunology. The co-investigators in the study were Professors Ashley Woodcock and Adnan Custovic.