A randomized double‐blind crossover study of indoor air filtration and acute changes in cardiorespiratory health in a First Nations community

Abstract

Few studies have examined indoor air quality in First Nations communities and its impact on cardiorespiratory health. To address this need, we conducted a crossover study on a First Nations reserve in Manitoba, Canada, including 37 residents in 20 homes. Each home received an electrostatic air filter and a placebo filter for 1 week in random order, and lung function, blood pressure, and endothelial function measures were collected at the beginning and end of each week. Indoor air pollutants were monitored throughout the study period. Indoor PM 2.5 decreased substantially during air filter weeks relative to placebo (mean difference: 37 lg/m 3 , 95% CI: 10, 64) but remained approximately five times greater than outdoor concentrations owing to a high prevalence of indoor smoking. On average, air filter use was associated with a 217-ml (95% CI: 23, 410) increase in forced expiratory volume in 1 s, a 7.9-mm Hg (95% CI: À17, 0.82) decrease in systolic blood pressure, and a 4.5-mm Hg (95% CI: À11, 2.4) decrease in diastolic blood pressure. Consistent inverse associations were also observed between indoor PM 2.5 and lung function. In general, our findings suggest that reducing indoor PM 2.5 may contribute to improved lung function in First Nations communities. Practical ImplicationsIndoor air quality is known to contribute to adverse cardiorespiratory health, but few studies have examined indoor air quality in First Nations communities. Our findings suggest that indoor PM 2.5 may contribute to reduced lung function and that portable air filters may help to alleviate these effects by effectively reducing indoor levels of particulate matter.

Cardiovascular and lung function in relation to outdoor and indoor exposure to fine and ultrafine particulate matter in middle-aged subjects

“…indoor concentrations of PM 2.5 in a panel study of elderly especially during winter (Simoni et al, 2003) and in an indoor air filtration crossover study with young adults (Weichenthal et al, 2013). By contrast, our investigation encompassed only non-smokers without asthma, living in non-smoking homes and lung function was not associated with PM 2.5 only with PNC levels.…”

“…Moreover, two short-term intervention studies with filtration of indoor air resulting in 60-70% decrease in indoor PNC and/or PM 2.5 for 2-7 days, in areas with either traffic or wood smoke pollution, showed increased MVF in the subjects, including elderly people (Allen et al, 2011;Brauner et al, 2008a). However, a third air filtration study among young healthy subjects showed no effect on MVF (Weichenthal et al, 2013). No effect of 24-hour exposure to air from a busy street, with a PNC of around 10,000 particles/cm 3 , was found on MVF in young healthy adults (Brauner et al, 2008b).…”

Indoor air quality in 24 California residences designed as high-performance homes

“…Research efforts including both simulations and field measurements have demonstrated increased negative health effects or poor IAQ in efficient or retrofitted residences that did not sufficiently address IAQ provisions (Emmerich et al, 2005;Milner et al, 2014;Offermann, 2009;Wilson et al, 2013). Yet, other research efforts that have consistently included IAQ best practices have demonstrated improved health outcomes and generally reduced pollutant levels (Breysse et al, 2011;Jacobs, 2013;Kovesi et al, 2009;Leech et al, 2004;Noris et al, 2013a;Weichenthal et al, 2013). These mixed research findings substantiate the concerns of those who are concerned that efficiency may be implemented in residences without sufficient IAQ countermeasures.…”

Measurement-Based Evaluation of Installed Filtration System Performance in Single-Family Homes

“…Enhanced filtration and other particle removal systems (described collectively in this document as "filtration") have the potential to reduce PM 2.5 concentrations and exposures (Barn et al 2008;Macintosh et al 2008). Recent studies showed health benefits from filtration in homes and commercial buildings (Fisk 2013), including some that may be linked to cardiovascular disease (Lin et al 2011;Weichenthal et al 2013), and other studies that found reduction in symptoms of asthma, allergies etc. (Sublett et al 2010).…”