Does cleaner air improve student performance? A new study on Madrid’s low emission zone finds better air quality led to higher exam scores, but the recent rollback of the policy raises questions about what’s next.
In the last decades, various policies have been implemented to reduce air pollution, not only because it is intrinsically linked to global warming, but also to improve public health outcomes. Traffic restriction plans have gained popularity, as vehicle emissions are a major source of urban air pollution.
What about the impact of air pollution on the academic performance of students? In a new study, we – Manuel T. Valdés and Mar C. Espadafor (Universidad Nacional de Educación a Distancia, Madrid) and Risto Conte Keivabu (Max Planck Institute for Demographic Research) examine whether the implementation of a low emission zone (LEZ) in the city of Madrid, known as Madrid Central, in late 2018 improved the academic performance of students schooled in the designated area.
Several reasons led us to assume that LEZ may have a positive impact on students’ performance. Air pollution is known to harm academic performance by impairing cognitive function and exacerbating health issues like asthma, rhinitis, and allergies, which can lead to more frequent school absences. Additionally, reduced traffic may lower noise levels, decrease stress, improve sleep quality, and shorten commute times, all factors that positively impact learning.
A Cleaner Environment, Better Academic Outcomes?
We have analysed the impact of LEZ on school-average scores in the EvAU, a regionally-standardised external assessment required for university admission. Schools within the LEZ saw their average scores improve by 20% of a standard deviation, a substantial effect, particularly for students seeking entry into the most competitive university programs. Furthermore, schools located within 0.5km of the LEZ’s borders also benefited from it, but not schools further away. Finally, the academic gains grew over time, suggesting that prolonged exposure to better air quality yields cumulative benefits. Importantly, we rule out the possibility that these improvements were driven by changes in the district’s population, which may have become more attractive due to reduced traffic and pollution.
This study offers valuable insights into the wide-ranging benefits resulting from the implementation of a low-emission zone successful in improving air quality. Madrid’s LEZ not only met its primary goal of reducing pollution but also had positive effects on students’ academic performance. These results demonstrate that evaluating the policy solely in terms of its ability to reduce traffic-related emissions overlooks its broader contribution, which may extend to other outcomes such as health, workplace productivity, traffic safety, or overall well-being.
The Reversal of Madrid Central: A Setback for Policy Progress
In September 2024, the TSJM (Tribunal Superior de Justicia de Madrid) overturned Madrid Central’s LEZ policy, citing procedural issues in its implementation. This decision represents a step backwards, considering the significant positive impacts identified in this study. While other cities like London and Paris are making their low-emission zones increasingly strict, Madrid is now moving in the opposite direction.
Interestingly, while Spain has contingency plans in place to protect students during extreme temperatures, such measures do not yet exist for periods of poor air quality, despite its well-documented impact on health and learning outcomes. This highlights a critical gap in policy that governments must address. Broader implementation of LEZs and similar measures could help shield students from the dual threats of climate change and air pollution, fostering healthier and more equitable learning conditions.
Read more about the effects of air pollution on school performance in this Digest written for the Mapineq Project: Air pollution affects students’ school performance unequally.
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This article is based on this post by Manuel Valdés, Mar Espadafor & Conte Keivabu, first published on Population Europe.