Health Risks of Indoor Exposure to Particulate Matter Workshop Summary (2016) / Chapter Skim
Currently Skimming:
5 Exposure Mitigation
5 Exposure Mitigation
Pages 59-72
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 59... ...
Indeed, Fisk said, the filtration of incoming outdoor air and recirculated indoor air should be the first approach taken to mitigate individual exposure to PM. He added that there are also techniques, such as using ion generators and increasing air movement, to enhance particle deposition on indoor surfaces.
|
From page 60... ...
The factors that affect particle removal include the rate and duration of air flow, the particle removal efficiency as a function of particle size, and the location of the filter relative to pollutant sources and to the location of a building's occupants. Factors affecting energy and cost include airflow resistance, pressure drop, fan and motor efficiency, and the particle-holding capacity as it relates to the filter's lifetime.
|
From page 61... ...
with an air flow rate of approximately 4.4 air exchanges per hour (Jump et al., 1996; Stephens et al., 2011) , Fisk calculated that the total removal rate is less than 10 percent of the indoor particle load per hour.
|
From page 62... ...
. Fisk then discussed the common belief that better filters will substantially increase energy costs because they will increase airflow resistance.
|
From page 63... ...
There is some evidence of benefit in homes with large sources of allergens, but only a fraction of health outcomes improved. The second conclusion was that the greatest potential comes from using better filtration to reduce indoor concentrations of outdoor PM, thus reducing the morbidity and mortality associated with outdoor air PM.
|
From page 64... ...
Fisk said he also believes that there is a need to better understand the relative health risks of outdoor PM versus PM that is generated indoors and also how filtration can be a tool to differentially affect exposures and risks. METHODS AND APPROACHES FOR CONTROLLING EXPOSURE TO BIOLOGICAL AEROSOLS2 One of the measurables that is specific to biological particles, Sergey Grinshpun said, is the percentage of airborne organisms that are viable.
|
From page 65... ...
Ozone generation devices are available but Grinshpun questioned their utility for removing indoor PM or reducing the viability of microorganisms in indoor air. Grinshpun and his colleagues have shown that commercially available ozone generators do not remove particles but instead create new ones (Grinshpun et al., 2010)
|
From page 66... ...
"With these methods, we do not care about concentration, we just want to kill viable microorganisms," Grinshpun explained. He noted that some commercially available air cleaners use ion emission, ozone generation, and photocatalytic oxidation to inactivate microorganisms.
|
From page 67... ...
Grinshpun also expressed caution about the use of so-called antimicrobial respirator filters, given that the risks of inhaling biocidal agents or having them come in prolonged contact with skin are not known. MITIGATING PARTICLE EXPOSURE IN LOW-SOCIOECONOMIC HOUSEHOLDS3 Low socioeconomic status is often equated with low income, Brett Singer noted, but it also is correlated with low education and, more importantly, low status and low access to information, all of which are important when it comes to thinking about changing behavior or practice.
|
From page 68... ...
"You can get very effective outdoor particle reductions with a recirculating system," Singer said. He noted that a simulation analysis using measured parameters conducted by Brent Stephens and his colleagues (Zhao et al., 2015)
|
From page 69... ...
He noted that efforts to get smokers to stop smoking indoors have been successful, particularly in low-socioeconomic homes, and that when smokers stop smoking indoors, it does produce meaningful reductions in indoor levels of PM2.5 (Semple et al., 2015; Wilson et al., 2012; Zhang et al., 2012)
|
From page 70... ...
The best control, then, starts with a good building, Singer said in summary: one with an airtight envelope, a vented range hood that is also quiet (so that it will be used) , a central forced air HVAC system with an efficient blower and a 2- to 5-inch filter slot, robust venting of combustion appliances, and limited use of carpeting, except perhaps in the case of housing for the elderly where slipping on uncarpeted surfaces can be hazardous.
|
From page 71... ...
and European markets for air purifiers, he would like to see more research to identify the various byproducts produced by some of the methods for removing bioaerosols from circulation and to determine the optimal condition under which a given method is most efficient at reducing exposure without doing any harm. He said in response to a question about ozone production from ion generators that no device that emits ozone should be deployed and that he has tested ion generators that do not emit any measurable ozone.
|
From page 72... ...
He also responded to a question about air quality in net-zero energy homes by noting that such homes also need to make judicious use of effective ventilation. The one criticism Singer had of some of these homes is that they may forgo range hoods in the mistaken belief that cooking on electric stoves does not produce UFPs, which in fact it does.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.