Air pollution clouds the mind: Evidence from real-time monitoring in Kenya

Air pollution is usually discussed as a threat to physical health. Fine particulate matter, or PM2.5, is linked to mortality, respiratory disease, cardiovascular illness, and neurological disorders. These harms are especially salient in low- and middle-income countries, where urbanisation, traffic growth, industrial activity, waste burning, and biomass combustion often coincide with limited monitoring and regulatory capacity.

But air pollution may also impose a more immediate and less visible cost: it may make it harder for people to think clearly.

This matters for development policy. Cognitive performance is central to learning, work, financial decisions, health decisions, and productivity. If pollution affects cognition not only over the life cycle but also in the moment – during a test, a work task, a business transaction, or a health decision – then the economic costs of pollution may be larger than standard health-focused estimates suggest.

In new research, we study this question using data from Kenya that links real-time air pollution exposure to adult cognitive performance (Ma et al.). We use the fifth round of the Kenya Life Panel Survey, a long-running study following adults originally enrolled in a school-based deworming programme in western Kenya. In the most recent survey round, more than 5,000 adults completed a detailed cognitive assessment while field officers carried portable air quality monitors. These monitors recorded PM2.5 during the assessment itself, allowing us to measure the pollution environment at the time and place where cognition was being tested.

Read the full VoxDev article here.