J Am Coll Cardiol

HEPA air purifiers lower systolic blood pressure in high-risk adults

August 8, 2025

Study details: A pragmatic randomized crossover trial enrolled 154 adults (mean age, 41 years; 59.7% women) residing adjacent to highways to assess the effect on BP of in-home HEPA filtration vs. sham filtration over two 1-month intervention periods, separated by a 1-month washout. BP and indoor particulate matter (PM) concentrations were measured at baseline and after each intervention. Linear mixed models adjusted for covariates were used to analyze outcomes.

Results: HEPA filtration significantly reduced indoor PM compared with sham and outdoor levels. Among participants with elevated baseline systolic BP (SBP ≥120 mm Hg), HEPA filtration led to a mean SBP reduction of 2.8 mm Hg (P=0.03), while sham filtration resulted in a 0.2 mm Hg increase (P=0.85), yielding a net 3.0 mm Hg difference favoring HEPA (P=0.04). No significant effect was observed on diastolic BP or in participants with normal baseline SBP.

Clinical impact: These findings support the use of in-home HEPA air purifiers as a non-pharmacologic intervention to achieve modest but clinically relevant reductions in SBP among adults with elevated baseline values, even in settings with relatively low PM2.5 concentrations. Incorporating HEPA filtration may be considered as part of a comprehensive cardiovascular risk reduction strategy, particularly for individuals at risk of hypertension due to environmental exposures.

Source:

Brugge D, et al. (2025, August 6). J Am Coll Cardiol. Effect of HEPA Filtration Air Purifiers on Blood Pressure: A Pragmatic Randomized Crossover Trial. https://pubmed.ncbi.nlm.nih.gov/40767818/