| Carpet is known to be a reservoir for biocontaminants if it isn't kept clean and dry. Allergens, such as mold spores or dust mites, accumulate in carpet and thrive after wetting with water, triggering allergies or asthma symptoms in children. The purpose of this study is to evaluate the removal of biocontaminants from carpet in dry and wetted conditions that simulate normal circumstances in home. The hypothesis tested is that physical methods, such as steam-vapor or high flow hot water extractor, are as effective as chemical agents eliminating biocontaminants from carpet.;Available treatment regimes for controlling carpet contaminants were evaluated through literature review and experimentation. Four low-hazard, nondestructive methods were selected as treatments: steam vapor, regular vacuuming, quaternary ammonia application, and natural plant extract. Carpets were inoculated with dust mites and Cladosporium spp., a common indoor mold, prior to treatment. Only steam demonstrated a consistent reduction of dust mites (p<0.001), and dust mite allergen (p<0.05). Steam was also found to inactivate over 99, 92, and 99% of mold spores in contaminated carpet samples incubated in a high humidity condition for 24 hours, 7 days, and 30 days respectively (p<0.001). Steam had been shown to eliminate viable mold spores in carpet, but the lowest effective temperature or contact time had not been established.;The effectiveness of steam vapor in reducing the number of viable spores on carpet as a function of temperature and contact time was evaluated. Wetted carpet was inoculated with mold spores and treated with steam for 0, 2, 4, 8, 12, 16 or 20 seconds. Temperature was measured at the carpet backing for each treatment interval. 12 seconds of contact time, which correspond to a carpet temperature of 62 degree Celsius, was needed to eliminate 95% of viable spores (p<0.001).;Steam is an effective treatment for carpet allergens such as dust mite and common indoor mold spores. Steam may be applied to carpet after minor water incidents to remove actively growing molds after drying, could be used to kill hardy-mold spores. Allergen reduction in carpet using steam is a viable means of mitigating carpet as reservoir for bio-contaminants. |
