Breathing cleaner air indoors promotes healthy blood pressure levels

Using an air filtration system facilitates improved air quality around the house by reducing indoor exposures to particulate matter, which, in turn, exerts a favourable effect on systolic blood pressure (SBP), a study has found.

Researchers conducted a systematic review of randomized controlled trials evaluating the effects of using personal air cleaners (PACs), including high-efficiency particulate air filters and electrostatic precipitators, as opposed to sham filtration. Outcomes included PM_2.5 exposure and SBP.

Ten studies involving a total of 604 participants met the inclusion criteria. The PM_2.5 concentrations at baseline were categorized using the WHO criteria. Two studies reported low air pollution exposure levels (35 μg/m³), while one study was classified as indeterminate as PM_2.5 was not quantified.

Median study duration was 9 days in nine studies, while the remaining study lasted 12 months. In general, PAC use yielded an absolute reduction in PM_2.5 of 20.9 μg/m³, which translated to a relative reduction of 55.9 percent.

Over a median follow-up of 13.5 days, PACs were associated with a significant reduction in mean SBP of around 4 mm Hg (−3.94 mm Hg; p=0.01) and a nonsignificant decrease in mean diastolic blood pressure (−0.95 mm Hg; p=0.32).

Subgroup analyses did not detect heterogeneity of effect by age, level of particulate exposure, or study duration.

Given the variation in study design, more studies are needed to validate the present data and better quantify the observed benefits for systolic BP associated with the use of personal air cleaners.