Ex - post evaluation of a program to reduce critical episodes due to air pollution in southern Chile

There is enough scientific evidence that associates air pollution by particulate matter (PM) with negative impacts on health. However, one-third of the world's population uses highly polluting fuels for cooking, heating, or lighting, especially in low- and middle-income countries. Due to the above, the environmental authorities of most of the countries have established different short-, medium-, and long-term regulations to reduce this pollution. It should be noted that it is challenging to identify the real effectiveness of this type of regulation since it is necessary to determine whether the pollution was reduced exclusively by the implementation of that regulation or due to other confusing factors. To address this issue, the present study performs an ex - post evaluation of the Critical Episodes Management program that imposes restrictions on the use of firewood heaters during pre-emergency and emergency episodes to reduce air pollution in the short-term in the city of Temuco, Chile (one of the most polluted cities in Latin America). Specifically, a fixed-effects panel data regression is applied to hourly concentrations of particulate matter data, controlling by meteorological and seasonal factors. The results show that restrictions on the use of firewood heaters generate a significant reduction in PM₁₀ and PM_2.5 concentrations during pre-emergency episodes (9.2% and 17.5%) and emergency episodes (5.9% and 16.3%). Thus, it can be concluded that this program is useful, but it must be complemented by others medium- and long-term environmental programs.