Home HEPA purifiers improve cognitive speed in older adults

In a randomized study of 119 adults aged 30-74 in Somerville, Massachusetts, using a HEPA air purifier for one month led to a 12% faster performance on an executive function test. The improvement was observed in participants aged 40 and older. The findings suggest that reducing indoor particulate matter may benefit brain health.
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The study involved 119 participants aged 30-74 in Somerville, Massachusetts, an area with elevated traffic-related pollution due to nearby highways. Participants used both a real HEPA purifier and a sham version for one month each, with a break between. The cognitive test measured visual memory, motor speed, and executive function through line-drawing tasks.
The 12% improvement in executive function appeared only in those 40 and older, roughly 42% of the sample. This benefit is comparable to gains from increased daily exercise, and even small cognitive declines are linked to higher mortality risk.
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