A citizen-science project explores the association between air pollution and mental health
We all have days when it is more difficult to concentrate. We normally blame ourselves for this (not enough sleep, too many distractions), but one of the reasons could simply be the air we are breathing. This is what recent evidence from the European citizen-science study CitieS-Health seems to suggest. The project, co-led by ISGlobal researchers and Ideas for Change, set out to measure how pollution affects the mental health of Barcelona city residents. It is a powerful example of what can be achieved with citizen engagement and support.
The power of citizen data
The subject of this study was chosen by Barcelona residents themselves during a participatory process that took place in 2019 and involved over 1,000 inhabitants. During the study, nearly 300 volunteers provided information on their habits and mobility over the course of 160 days. They took several tests of attention span and processing speed, answered a series of questions on stress level, quality of sleep and mood via an app, and shared GPS data that made it possible to estimate the time spent in different parts of the city and their exposure to pollutants. They also wore a sampling device to measure the levels of nitrogen dioxide concentration they were exposed to over the course of a week.
The effect of air pollution
The analysis shows that people have greater difficulty concentrating on the days when air pollution is highest: their reaction time and cognitive performance dropped by about 5% on high-pollution days compared to days with clean air. Stress levels also increase on polluted days (by roughly 0.5 on a 0-10 scale, compared to clear days), but people living near green or blue spaces (such as the sea) were less affected.
Going beyond the results
The results of the study, which will soon be published in a scientific journal, are only the first step. With the support of local communities, participants prepared a series of recommendations and citizen actions to combat air pollution and improve mental health.
