Air Cleaners Improve COPD Health

Reduce Symptoms and Flare-ups

Background

Outdoor air pollution has known adverse effects on respiratory health. Studies also show that indoor particulate matter is also associated with worse COPD outcomes. This is a particular concern as most individuals spend the majority of their time indoors especially with the COVID-19 pandemic. Unlike outdoor air, indoor air can be modified for individuals. Although using air cleaners have improved respiratory symptoms in those with asthma, such interventional studies have not been conducted in those with COPD.

Example of a medical-grade HEPA Air Purifier

The Austin Air HealthMate® website states that the system removes up to 99% of all airborne contaminants including viruses, bacteria, dust, dander and allergens. The carbon blend used in this filter also effectively removes chemicals, gases and odors.

Study

Dr. Nadia N. Hansel and colleagues from Johns Hopkins University School of Medicine in Baltimore studied whether placement of active portable high-efficiency particulate air cleaners can improve COPD health.

Former smokers with moderate to severe COPD received either active or sham (pretend) high-efficiency particulate air cleaners for 6 months. Participants were included IF their home had particulate matter above 10 μg/m ³ measured over 2-7 days. This value was selected as the World Health Organization recommends that indoor air quality be less than 10 μg/m³.

Each participant received either two portable air cleaners ((Austin HealthMate HM400) with HEPA and carbon dioxide filters for reduction of particulate matter and nitrogen dioxide (NO2) OR two sham air cleaners. Air cleaners were placed in the bedroom and the room that the participant reported spending the most time.

Particulate matter is a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. NO2 primarily gets in the air from the burning of fuel and forms from emissions from cars, trucks and buses, power plants, and off-road equipment.

Size of 2.5 micron particulate matter compared with sand and hair

The main outcome was quality of life as measured on the St. George’s Respiratory Questionnaire (SGRQ) , while other outcomes were respiratory symptoms, risk of a flare-up (exacerbation), and rescue albuterol use.

Results

Of the 375 individuals screened, 31% had low, or acceptable, levels of particulate matter in their home and were not randomized.  116 participants were randomized with 58 in each group. 85% completed the study. Average age was 66 years, and average FEV1 was 54% predicted. There was a 61% greater reduction in particulate matter and a 24% reduction in NO2 at 6 months with the air cleaners (see image).

Reduced levels of particulate matter and nitrogen dioxide with air cleaners (brown symbols and lines) compared with placebo or sham treatment (blue symbols and lines)

There was no significant difference in the total SGRQ score between the two groups. However, the active filter group had a greater reduction in respiratory symptoms, lower albuterol rescue use, and a lower rate of moderate but not severe flare-ups (exacerbations) compared with the sham group (see image). Those spending more time indoors were more likely to show improvement.

Differences in COPD outcomes

The study results were published on February 15, 2022, in the American Journal of Respiratory and Critical Care Medicine (volume 205; pages 421-430).

Conclusions

The authors state that this is the first environmental intervention study in former smokers with COPD showing that air cleaners improve COPD health.

My Comments

Overall, the study showed that individuals who spend more time indoors, have a lower FEV1, and who used air cleaners greater than 80% of the time were most likely to benefit from cleaner air in their home. Many patients in my practice fit this profile – they stay indoors especially during the cold, winter months and during the current COVID-19 pandemic.

At times, I have been asked by patients whether an “air filter’ would help their COPD. My previous answer was that I didn’t know as there was no evidence. The current study is the first to evaluate air cleaners in COPD patients. The findings are consistent with studies that show benefit in those with asthma. Moreover, the overall improvements in COPD outcomes are similar, if not better, than results with standard inhaled bronchodilators alone or in combination with inhaled corticosteroids used daily in the treatment of COPD.

According to the website (https://austinair.com/) one Austin Air HealthMate® air cleaner (used in this study) costs $715. Certainly, other high efficient air cleaners are available and you can do comparative shopping. Possible concerns of using air cleaners include a higher electricity cost and possible noise when used in the bedroom if you are a “light” sleeper.