Impacts of Indoor Air Quality on Cognitive Function

The Global CogFx study, a research project conducted among 302 office workers in six countries (China, India, Mexico, Thailand, the UK and the US) aims to understand the effects of indoor air pollution on cognitive performance.

Our paper published today shows the significant acute effects of PM2.5 and ventilation on cognitive test performance. These findings add to a growing body of evidence of how air pollution affects brain health, both short- and long-term.

In addition, our paper suggests that the effects of PM25 are not exclusive to children or older populations, but are also present among young adults (the mean age of study participants was 33 years old).

Some key takeaways:

  • We developed an ecological momentary assessment framework to administer cognitive tests based on real-time indoor PM2.5 and CO2 measurements.
  • We found 0.8-0.9% slower response times for every 10ug/m3 increase in PM2.5. Throughput (correct responses per minute) was 0.8-1.7% lower for the same concentration increase.
  • We also found effects of CO2 (a proxy for ventilation) on cognitive function. For every 500ppm increase, we saw response times 1.4-1.8% slower, and 2.1-2.4% lower throughput.
  • We did not find a lower threshold at which effects from low ventilation are no longer present.

In addition to the well-established health benefits from lower PM2.5 levels (e.g. reductions in cardiovascular disease, asthma attacks, premature mortality), and from higher ventilation rates (e.g. reduced infectious disease transmission, fewer sick-building symptoms, and reduced absenteeism), our findings provide further incentive to improve air quality in indoor spaces.

Higher ventilation rates and enhanced filtration that exceed current minimum targets are important public health strategies, and we must pursue them.

“Associations between acute exposures to PM2.5 and carbon dioxide indoors and cognitive function in office workers: a multicountry longitudinal prospective observational study,” Jose Guillermo Cedeño Laurent, Piers MacNaughton, Emily Jones, Anna S Young, Maya Bliss, Skye Flanigan, Jose Vallarino, Ling Jyh Chen, Xiaodong Cao, and Joseph G Allen, Environmental Research Letters, online September 9, 2021, doi: 10.1088/1748-9326/ac1bd8