provide for amplification and/or infiltration and dissemination of allergens. Inappropriate control strategies have been associated with nearly all problem buildings.
Recommendation: Improve the design, installation, use, and maintenance of residential and commercial HVAC equipment, for both new and existing construction, in order to minimize allergen reservoirs and amplifiers. These improvements should be based on recommendations developed by the American Society of Heating Refrigerating and Air Conditioning Engineers (ASHRAE).
Carpeting can provide niches for both the accumulation and production of allergens, and has been characterized by some as a ''cultivation medium" for microorganisms when wetted. Carpeting can also serve as a reservoir for pollen and pollen fragments. The magnitude of the potential significance of carpeting as a source and reservoir of indoor allergens indicates that it should be given consideration as a serious problem.
Recommendation: Expand the scope of the Carpet Policy Dialogue Group of the Environmental Protection Agency to consider the serious problem of carpets as a source and reservoir of indoor allergens.
Standards have been established by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) for acceptable temperature, humidity, and ventilation as they relate to human comfort. However, little attention is given in these standards to the protection of buildings, furnishings, and construction materials from water damage, and the potential for subsequent adverse health effects.
Recommendation: Develop consensus standard recommendations for controlling moisture in naturally and mechanically ventilated buildings. These recommendations, designed to help control microbial and arthropod aeroallergens and allergen reservoirs, should be developed by ASHRAE and be included in their Standard Series 55 (thermal environmental conditions for human occupancy) and Standard Series 62 (ventilation for acceptable indoor air quality).
Dry vacuum cleaning is traditionally used to remove dirt and debris from the fibrous pile of carpets. Little information is available, however, on the effectiveness of this cleaning method in removing the various types of particles, including specific allergens that may adhere to pile fibers, carpet backing, and other furnishings. In addition, the physical cleaning process itself may be sufficient to disperse fine allergenic particles.