The air we breathe:

Past, present and future

The air we breathe: Past, present and future

Air quality is a complex problem involving not only physical-chemical factors, but also sociocultural, economic, and institutional variables. The report “The air we breathe: past, present and future – PM2.5 air pollution in Central and Southern Chile” focuses on the impacts and the role played by the residential sector and its PM2.5 emissions, taking the above factors and variables into account. This interdisciplinary research integrates information from multiple databases, numerical simulations, and interviews and workshops with different stakeholders in order to characterize not only current air quality but also the evolution of air pollution since pre-Colombian times, and the factors influencing its future evolution.

PM2.5 consists of fine, fully inhalable particulate matter; in other words, particles smaller than 2.5 microns. Every winter, it leads to a deterioration of air quality in cities in central and southern Chile. According to estimates from the Environment Ministry (MMA), in 2018 around 10 million citizens were exposed to average daily PM2.5 concentrations higher than those allowed under current Chilean law (50 μg/m3) and far above the 25 μg/m3 limit suggested by the World Health Organization (WHO). These levels of PM2.5 have serious impacts on human health and, according to MMA estimates, caused nearly 3,600 premature deaths that year.

The air quality in Chile has gradually deteriorated over the last 2,000 years, and this deterioration has increased rapidly over the last century, in direct association with population growth, urban expansion, and economic growth in Chile. However, there has been a gradual improvement in air quality over recent decades as decontamination plans and public policies for monitoring and controlling emissions have been implemented. Nonetheless, this improvement is still insufficient and there is a lack of evidence of the efficiency and effectiveness of these policies.

Summary for Policymakers

This publication should be cited as:
Huneeus, N., Urquiza A., Gayó, E., Osses, M., Arriagada, R., Valdés, M., Álamos, N., Amigo, C., Arrieta, D., Basoa, K., Billi, M., Blanco, G., Boisier, J.P., Calvo, R., Casielles, I., Castro, M., Chahuán, J., Christie, D., Cordero, L., Correa, V., Cortés, J., Fleming, Z., Gajardo, N., Gallardo, L., Gómez, L., Insunza, X., Iriarte, P., Labraña, J., Lambert, F., Muñoz, A., Opazo, M., O’Ryan, R., Osses, A., Plass, M., Rivas, M., Salinas, S., Santander, S., Seguel, R., Smith, P., Tolvett, S (2020). Summary for policymakers. The air we breathe: past, present and future – PM2.5 air pollution in Central and Southern Chile. Centro de Ciencia del Clima y la Resiliencia (CR)2, (ANID/FONDAP/15110009), 16 pp. Available in