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

Abstract

Dry steam cleaning, which has gained recent attention as an effective method to reduce house dust mite (HDM) allergen concentration and loading in carpets, was evaluated in this study for its efficacy in lowering levels of polycyclic aromatic hydrocarbons (PAHs) as well as HDM allergens. Fifty urban homes with wail-to-wall carpets, mostly low-income and with known lead contamination, were studied in 2003 and 2004. Two carpet-cleaning interventions were compared: Repeated HEPA (High Efficiency Particulate Air filtered) vacuuming alone and repeated HEPA vacuuming supplemented with dry steam cleaning. Vacuum samples were collected to measure carpet loading of dust and contaminants immediately before and after cleaning. Paired comparisons were conducted to evaluate the effectiveness of the cleaning protocols in reducing the levels of PAHs and HDM allergens in carpets. The results indicated that both cleaning methods substantially reduced the loading of PAHs and HDM allergens as well as dust in carpets (p < 0.0001). The reductions in loading of dust (64.4%), PAHs (69.1%), and HDM allergens (85.5%), by dry steam cleaning plus repetitive HEPA vacuuming were larger than the reductions by regular HEPA vacuuming alone: dust (55.5%), PAHs (58.6%), and HDM allergens (80.8%), although the difference was statistically significant only for dust and PAHs. We conclude that intensive HEPA vacuum cleaning substantially reduced the loading of PAHs and HDM allergens in carpets in these urban homes and that dry steam cleaning added modestly to cleaning effectiveness.

Home and school environmental assessment and remediation

“…Studies examining the effect of vacuuming in reducing dust mite concentrations have yielded mixed results; however, the consensus is that vacuuming does decrease the bulk of dust mite allergen in carpet [13,14]. The effi ciency of dust mite allergen extraction from carpets by vacuuming is largely infl uenced by pile height and the overall condition of the carpet.…”

“…However, some evidence suggests that dry steam cleaning, when added to an intensive vacuuming regimen, provides some added reduction in dust mite allergen compared with vacuuming alone. In 2009, Yu et al [14] found that an additional 5% reduction in dust mite allergen was achieved when dry steam cleaning was added to a regular vacuuming regimen. A similar study reported that lower levels of dust mite allergen were sustained for a greater duration when a dry steam cleaning treatment was added to a rigorous vacuuming schedule [16].…”

Revisiting Dust and Soil Ingestion Rates Based on Hand-to-Mouth Transfer

“…Statistics after cleaning (mg/cm 2 ) were a minimum of 0.0019, a maximum of 0.289, a median of 0.0102, an arithmetic mean of 0.0463, an arithmetic standard deviation of 0.0863, a geometric mean of 0.0146 (mean, standard deviation, and geometric mean were calculated from the raw data provided by Roberts et al 1999). Yu et al (2009) collected 50 dust samples from carpets in New Jersey homes before and after cleaning. The houses were identified as mostly low-income, urban residences.…”

Inactivation of Dust Mites, Dust Mite Allergen, and Mold from Carpet

“…(69) A steam vapor machine differs from the commonly known "steam cleaner" which is a hot-water carpet shampooing machine. Steam was demonstrated to be effective in reducing dust mite populations.…”