Air quality is the world’s biggest environmental threat. There is substantial research that shows that when there is more particulate matter in the air, more people get sick. And when there is long-term exposure, people die. We also know that sometimes air quality monitoring stations do not tell the whole story. And that when people live and are exposed to direct sources of air pollution, such as working in environments with higher diesel exhaust exposure, or live close to highways, there is an even clearer link between exposure and disease. Finally, after more than 100 years of data, we have finally reached the conclusion that diesel exhaust is a proven human carcinogen, and that we must reduce exposure to these fumes if we want to reduce lung and bladder cancer.
The upside of this story is that the western world is at all-time lows in particulate matter concentrations. The United States has some work to do, but most major cities are meeting stringent requirements. Cars are much cleaner than they used to be. Overall reductions in pollution are upwards of 70% in most major cities. This is linked to increased life expectancy, and reduction of overall respiratory disease. In Chile we have also made some leaps, reducing Santiago’s air pollution by 66% in 25 years. But our newly approved fine particulate matter standard (PM2.5) shows us that we have yet a long way to go for clean air.
When President Bachelet returned to government in 2014 she told us that we could not delay the goal for cleaner air. We are now in the process of creating 14 new pollution attainment plans in 4 years, while typically a government is only able to create 2 of these plans in a presidential term. We did not wait for these plans to come into effect, but collaborated with our partners in the Ministry of Health, who decreed a sanitary alert which provided us the power to decree special emission constraints when air quality is bad. We started to ban visible smoke from stoves (forcing users to use certified stoves or dry wood) in 10 cities. Our results were a resounding success. While air quality was on an upward trend, we reverted the trend, reducing air quality episodes by 30% and annual exposure by 20 to 25%. We reduced hospital visits by 25,000 cases, and we estimate that we reduced premature mortality in roughly 270 cases. This year we are doubling down and including Santiago in this trend. We hope to reduce hospital visits by 75,000 cases, and prevent upwards of 750 cases.
Of course we are implementing pollution plans that make for structural measures to reduce pollution, but these take time to implement. We have laid out a plan to overhaul wood burning stoves in roughly 30% of homes in the south of Chile. We are going to retrofit weatherization in 40% of the homes, bringing them up to lower heating demands. And we are promoting the access to cleaner, drier wood, and supporting an emerging pellet manufacturing industry. We believe in 10 years we will meet our stringent daily air quality standards, and we will change the face of these southern cities. They will have better quality homes that use just the right amount of fuel. Keeping them warm but not at the expense of human health. We have implemented a carbon tax of power plants, and a pollution tax on cars based on their local air pollution. Diesel cars have reduced their participation in new cars sold by 30%. And old cars are subject to no-drive days if the air quality is bad in Santiago.
Overall we know that Chile’s biggest environmental threat needs to be addressed with our best effort. We are currently in the middle of implementing Chile’s largest, most massive effort aiming to address air quality. It’s based on sound science and solid economics. We are doing it the Chilean way, based on free market; knowing that externalities are distortions in the market that need to be internalized. But regardless… in the end we know the people of Chile are going to breathe easier and live healthier. And that is really all that matters.
By Marcelo Mena-Carrasco, PhD
Vice Minister, Ministry of Environment
Republic of Chile
@marcelomena