Using portable high-efficiency particulate air (HEPA) purifiers at home can significantly lower systolic blood pressure (SBP) in adults with elevated baseline readings, even in areas with relatively low overall air pollution levels, according to a study published Aug. 6 in JACC.

In the randomized crossover trial of 154 adults without known cardiovascular disease living near highways, Doug Brugge, PhD, et al., randomized participants to one month of either HEPA or sham filtration, followed by a one-month washout period with no filtration, and then the alternate treatment. BP measurements and participant questionnaires were collected at the start and end of each period. The mean age of participants was 41 years, 60% were women, 70% were non-Hispanic White and the majority were of higher socioeconomic status.

Particulate matter concentrations were measured in a subset of residences, and the mean change in BP between the HEPA and sham filtration periods was compared using linear mixed models. The authors note that models were adjusted for time invariant and time-varying covariates.

Researchers found that participants who entered the study with elevated SBP (>120 mm Hg) experienced an average 2.8 mm Hg reduction in SBP after one month of HEPA filtration. In comparison, SBP increased slightly (0.2 mm Hg) during a sham filtration period, resulting in a significant 3.0 mm Hg difference in favor of HEPA filtration. There was no significant impact on diastolic BP or among participants with normal SBP (<120 mm Hg).

"Our findings add to the growing literature that indicates that air purifiers have a clinically important beneficial effect on BP in near highway environments in a country with low PM2.5 concentrations relative to many places globally," write the authors. "…We believe it is a reasonable conclusion, given the lack of adverse effects, to recommend air purifier use for vulnerable populations, those with pre-existing risk of cardiovascular disease such as elevated BP, and those who live within 200 m of high traffic highways or 100 m of high traffic roads."

"For decades there has been majority support for improving domestic air quality – which has directly led to sustained improvements in public health," write Jonathan D. Newman, MD, FACC; Sanjay Rajagopalam, MD, FACC; and Robert D. Brook, MD, in an accompanying editorial comment. "...As [health care] professionals, it is our obligation to educate the public about this issue and support policies to improve the health and wellbeing of our patients – and all Americans."