Wildfire smoke: what do we know?

The first of a series on wildfire smoke.

Smoke from wildfires is no longer an issue for the region.

Wildfires, a common phenomenon in the West, attracted national attention this summer as smoke from wildland fires burning in Canada reached the East Coast. Smoke turned New York City’s and Washington D.C.’s skies orange and hazy during the day and hazy at night. Residents were forced to remain indoors, or wear N95 masks while traveling outdoors due to poor air quality. The Senators of the Western U.S. who attended a wildfire heard that they no longer needed the visual aids to show the smoke’s effects on their states. They could now see the same effects on the steps of Congress. Wildfires and smoke they create are no longer a concern for Western states only. They affect people all over the world.

In light of the growing awareness about wildfires and their danger to public health it is now more important than ever to act to combat the current wildfire crisis. However, some important questions remain. Further research is required to determine the health effects of wildfire exposure, to find the best ways to reduce exposure at the community level and to identify the most effective methods of mitigating the impact of future wildfires. Smoke’s serious health effects, especially for those who are vulnerable and for communities in general, require an immediate response. However, a targeted approach is also needed to minimize harm while coordinating with other health and environmental goals. This post is the first in a series of posts that will describe the harmful effects of smoke from wildfires and how communities can limit their exposure. In the second post, we will examine the causes of wildfires and discuss what the government can do to reduce the dangers caused by wildfires.

How can we prevent exposure to wildfire smoke?

The composition of smoke from wildfires varies with the type of material burned. However, PM _2.5 is a key pollutant which remains constant in all types of fires. PM _2.5, unlike most other pollutants is not designated by its chemical makeup but rather by its size. The size of PM _2.5 is what defines it, and makes it dangerous. It’s small enough to pass through the lungs into the bloodstream and be inhaled. Inhaled PM _2.5 can cause inflammation in the body that leads to heart and lung diseases. In principle, there is no safe level of exposure to PM2.5. Accordingly, when atmospheric levels of PM2.5 are high everyone should reduce their exposure as much as possible. The risk is even greater for vulnerable populations, such as those with pre-existing medical conditions, pregnant women, children and seniors. These groups are at particular risk and need targeted public health strategies that limit exposure.

For example, it is believed that the effects of PM _2.5 are more severe for infants and young children. Many school districts restrict outdoor activities, or advise students to stay at home if outdoor PM _2.5 levels are high. This policy is based on a sound logic. While outdoor PM _2.5 levels are well understood and consistent, indoorlevels can vary significantly from one building to another . This means that in some cases telling students to stay at home when the air quality is bad is counterproductive. When the air quality outside is bad, it may be better for a child to go to school if their indoor air is better than at home. It is more likely to happen if their school has an air filter system.

This issue is interconnected with other concerns. In order to address these concerns, it is important to conduct research on the relative indoor exposure of PM2.5 at schools and homes. This will help to ensure that school districts’ policies encourage children to remain in places where they are exposed to as little as possible of PM2.5, whether at home or at school. In order to support these programs, it is also necessary to increase monitoring of indoor air and provide greater access air filtration systems.

The concerns raised by students about PM _2.5 also apply to policies on air pollution more broadly. In recent years, indoor air quality monitoring and filtration have been given more attention due to wildfires and the COVID-19 epidemic. U.S. air pollution and environmental laws are generally limited to ambient outdoor air. They do not apply to indoor air. In order to ensure that we don’t expose people to more pollution, it is important to consider indoor air quality when addressing pollutants like PM _{and 2.5}.

Eric Macomber will join the Climate and Energy Policy Program and Stanford Law School in September 2022 as a Wildfire Legal fellow. His work is focused on issues of law and policy relating to wildfires and the wildland/urban interface.

This article was originally shared by Climate and Energy Policy Program on Substack.