Combined use of an electrostatic precipitator and a high-efficiency particulate air filter in building ventilation systems: Effects on cardiorespiratory health indicators in healthy adults

Abstract

High-efficiency particulate air (HEPA) filtration in combination with an electrostatic precipitator (ESP) can be a cost-effective approach to reducing indoor particulate exposure, but ESPs produce ozone. The health effect of combined ESP-HEPA filtration has not been examined. We conducted an intervention study in 89 volunteers. At baseline, the air-handling units of offices and residences for all subjects were comprised of coarse, ESP, and HEPA filtration. During the 5-week long intervention, the subjects were split into 2 groups, 1 with just the ESP removed and the other with both the ESP and HEPA removed. Each subject was measured for cardiopulmonary risk indicators once at baseline, twice during the intervention, and once 2 weeks after baseline conditions were restored. Measured indoor and outdoor PM and ozone concentrations, coupled with time-activity data, were used to calculate exposures. Removal of HEPA filters increased 24-hour mean PM exposure by 38 (95% CI: 31, 45) μg/m . Removal of ESPs decreased 24-hour mean ozone exposure by 2.2 (2.0, 2.5) ppb. No biomarkers were significantly associated with HEPA filter removal. In contrast, ESP removal was associated with a -16.1% (-21.5%, -10.4%) change in plasma-soluble P-selectin and a -3.0% (-5.1%, -0.8%) change in systolic blood pressure, suggesting reduced cardiovascular risks.

Possible aerosol transmission of COVID-19 and special precautions in dentistry

“…One disadvantage is that the filter may become a source of microbes if the retained microorganisms proliferate and enter back into the filtered air (Chuaybamroong et al, 2010). In addition, soiled HEPA filters are difficult to clean and expensive to replace (Day et al, 2018).…”

Assessment and mitigation of aerosol airborne SARS-CoV-2 transmission in laboratory and office environments

“…AHUs can be equipped with particle filters, e.g., minimum efficiency reporting value (MERV) or HEPA, with filtration efficiency dependent on particle size. HEPA filtration efficiency, f , is measured to be 99.994% at 50 nm, 99.98% at 0.1-0.2 mm, and >99.996% for particles >0.5 mm (Chuaybamroong et al 2010;Zhang et al 2014;Day et al 2018;Morono et al 2018). Because virus-laden particles are often expelled from the body in combination with proteins, salts, and water as droplets and aerosols (Dietz et al 2020), it is not yet clear whether aerosol transmission of SARS-CoV-2 is caused by suspended individual viral particles, of size $50À150 nm (Cascella et al 2020;Kim et al 2020), or larger respirable aerosols of size $1À5 mm (Singh and Kaur 2020; Wang and Du 2020).…”

Effectiveness of a portable air cleaner in removing aerosol particles in homes close to highways

“…Exposure to these particles has been associated with enhanced aeroallergen sensitization, exacerbation of existing asthma, and the incidence of asthma among young and adolescent children . Studies have shown an increased risk of cardiovascular disease in individuals living near major roadways, implicating traffic air pollutants such as PM 2.5 , UFP, and BC as potential sources . Indoor exposure to microorganisms, microbial cell debris, allergens, and other particles in house dust has also become an area of interest in asthma and allergy research because of the potential adverse health effects …”

“…[16][17][18][19][20][21] Studies have shown an increased risk of cardiovascular disease in individuals living near major roadways, implicating traffic air pollutants such as PM 2.5 , UFP, and BC as potential sources. [22][23][24][25][26][27] Indoor exposure to microorganisms, microbial cell debris, allergens, and other particles in house dust has also become an area of interest in asthma and allergy research because of the potential adverse health effects. 28,29 Portable air cleaners with high efficiency particulate air (HEPA) filtration and other high efficiency media have been evaluated for use in homes for the removal of smoke, dust, and fungal spores.…”