Hepa Air Filtration: an Effective Method of Reducing Household Pm Exposure

Carpeted bedrooms of 36 asthmatic children were monitored to examine the mass concentration of indoor aerosol particulate matter (PM), from non-smoking households, and the effect high efficiency particle arresting (HEPA) air filtration had on PM concentration. Concurrent indoor and outdoor monitoring was also undertaken. Mass concentration was determined gravimetrically using time weighted concurrent virtual impaction sampling. Indoor PM mass concentration was higher than outdoor PM mass concentration. The intervention reduced PM mass concentration in the air-filter group by approximately 50% (P<0.01); with mean indoor PM10 and PM2.5 mass concentrations falling from 42μg m and 25μg m to 21μg m and 14μg m respectively. PM mass concentration remained low for the length of the experiment while the control group PM mass concentrations fluctuated throughout the monitoring period. INDEX TERMS Particulate matter, HEPA air filter; Air filter intervention, Carpet, Asthma INTRODUCTION Many contaminants spanning a wide range of chemical, physical and biological species impact on respiratory function. Nevertheless, in terms of air pollutants, particulates are considered by many to be one of the biggest threats to human health (Jones, 1999). The consequences of PM inhalation can be manifest in a wide range of conditions that typically decrease in incidence whilst increasing in severity. Such conditions range from the most severe, such as: cancer; leukaemia; cardio-vascular disease; respiratory hypersensitivity and infection to the less severe, such as: allergy, rashes, fatigue and general ill-health (Etkin, 1994, Wilson and Spengler, 1996). In many Australian homes today, low indoor air exchange rates and a wide range of materials acting as sources and sinks of indoor air pollutants, means the quality of indoor air bears little resemblance to that of outdoor air (Jones, 1999). The quality of indoor air is often inferior to that of outdoor air, with the concentration of PM and many other indoor air pollutants exceeding concentrations outdoors (Samet et al., 1988). There are several major classes of indoor PM spanning combustion, plant, animal, mineral, home and personal care and radioactive particulates (Owen et al., 1990). The combustion of carbonaceous fuels produce a wide array of indoor PM species, many of which are found in high concentrations (Etkin, 1994, Lighty et al., 2000). Most combustion particles are elemental carbon followed by a significant percentage of condensed volatiles. Because of their high surface areas: carbonaceous particles tend to be ideal respiratory delivery vehicles for a range of bound substances, particularly aromatic hydrocarbons and transition metals (Lighty et al., 2000). ∗ Contact author email: [email protected] Proceedings: Indoor Air 2002