Effects of physical interventions on house dust mite allergen levels in carpet, bed, and upholstery dust in low-income, urban homes.

Abstract

House dust mite allergen exposure is a postulated risk factor for allergic sensitization, asthma development, and asthma morbidity; however, practical and effective methods to mitigate these allergens from low-income, urban home environments remain elusive. The purpose of this study was to assess the feasibility and effectiveness of physical interventions to mitigate house dust mite allergens in this setting. Homes with high levels of house dust mite allergen (Der f 1 + Der p 1 > or = 10 microg/g dust by enzyme-linked immunosorbent assay) in the bed, bedroom carpet, and/or upholstered furniture were enrolled in the study. Carpets and upholstered furniture were subjected to a single treatment of either dry steam cleaning plus vacuuming (carpet only) or intensive vacuuming alone. Bed interventions consisted of complete encasement of the mattress, box spring, and pillows plus either weekly professional or in-home laundering of nonencased bedding. Dust samples were collected at baseline and again at 3 days (carpet and upholstery only) and 2, 4, and 8 weeks posttreatment. We compared pretreatment mean allergen concentrations and loads to posttreatment values and performed between-group analyses after adjusting for differences in the pretreatment means. Both dry steam cleaning plus vacuuming and vacuuming alone resulted in a significant reduction in carpet house dust mite allergen concentration and load (p < 0.05). Levels approached pretreatment values by 4 weeks posttreatment in the intensive vacuuming group, whereas steam cleaning plus vacuuming effected a decrease that persisted for up to 8 weeks. Significant decreases in bed house dust mite allergen concentration and load were obtained in response to encasement and either professional or in-home laundering (p < 0.001). Between-group analysis revealed significantly less postintervention house dust mite allergen load in professionally laundered compared to home-laundered beds (p < 0.05). Intensive vacuuming and dry steam cleaning both caused a significant reduction in allergen concentration and load in upholstered furniture samples (p < 0.005). Based on these data, we conclude that physical interventions offer practical, effective means of reducing house dust mite allergen levels in low-income, urban home environments.

Indoor Environmental Exposures Among Children With Asthma Seen in an Urban Emergency Department

“…For example, the use of allergen-barrier mattress pads and pillow covers to reduce exposure to dust mites has shown inconsistent results. [22][23][24][25][26] In addition, reducing cockroach allergen in urban homes is challenging and in some studies has produced no apparent clinical benefit. 22,27 However, a recent intervention aimed at reducing exposure to multiple indoor allergens and ETS has produced a significant and sustained decrease in asthma symptoms.…”

Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets

“…Our results are consistent with those of Vojta et al . 4 who tested the effectiveness of a dry steam cleaner in reducing the HDM allergen levels in carpets for screened low-income, urban homes ( N = 11; HDM allergen concentration > 10 µg g −1 ) and found that both intensive vacuuming and vacuuming plus dry steam cleaning could reduce high levels of HDM allergens. They reported greater and longer lasting reductions of allergens with dry steam cleaning than with vacuuming alone.…”

“…4 Dry steam cleaning is believed to kill dust mites with high temperature vapor (above 100 °C), and simultaneously to soften and loosen sticky dust which is removed by a towel attached to the cleaning head or by subsequent regular vacuuming. In addition, the high temperature may help volatilize and remove PAHs and other chemicals in the carpets.…”

Home is Where the Triggers Are: Increasing Asthma Control by Improving the Home Environment

“…While vacuuming and/or steam cleaning may reduce exposure to mites and pet allergens, most studies have not assessed or demonstrated clinical improvements. 48,49 High efficiency particulate arrestor (HEPA) air filters may reduce exposure to pet allergens, but clinical impact is uncertain. [50][51][52] Multi-trigger, multi-component approaches more effective…”