Chilean authorities declared a pre-emergency environmental status in Santiago to combat a dense smog episode and high levels of fine particulate matter [1, 2].
The measure is critical because concentrated emissions during intense cold weather created dangerous air quality levels for the city's 6.3 million inhabitants [3]. These conditions pose significant risks to public health, necessitating immediate government intervention to reduce the volume of pollutants in the atmosphere [1, 4].
The Secretaría de Medio Ambiente and the Delegación Presidencial Metropolitana managed the response. Reports said the state of pre-emergency was first declared on Monday, May 25, 2024 [1]. This status was maintained through the following week as weather conditions persisted.
On Wednesday, May 27, 2024, the city experienced a particularly dense smog episode [1]. In response to the continuing crisis, a decree was issued to apply the pre-emergency status on Thursday, May 30, 2024 [4].
To lower the concentration of PM2.5, authorities implemented strict traffic restrictions across the Región Metropolitana [1, 4]. The government also issued a ban on the use of wood-burning stoves, which are a primary source of emissions during the cold season [1, 4]. These measures aim to prevent the air quality from reaching emergency levels that would require more drastic urban shutdowns.
Santiago's geography often traps pollutants, especially when cold air prevents the dispersion of smoke and vehicle exhaust. The current restrictions remain in place until atmospheric conditions improve, and particulate levels drop to safe margins [2, 3].
“Authorities restrict traffic and ban wood-burning stoves as dense smog and high particulate matter threaten public health.”
The repeated use of pre-emergency decrees in Santiago highlights the ongoing struggle between urban growth and the city's unique geography, which traps pollutants. By targeting both transport and residential heating, the Chilean government is attempting to mitigate the immediate health impacts of PM2.5, though the reliance on temporary decrees suggests a need for long-term systemic changes in energy and transit infrastructure.
