Last summer, when huge swaths of wildfire smoke blanketed much of the country, many of us got to know the Air Quality Index (AQI) for the first time. The AQI is EPA’s index for reporting air quality. You can think of the AQI as a color-coded yardstick that runs from 0 to 500: the higher the AQI number, the more pollution is in the air and the greater the health risks. When the AQI is 50 or under, it’s considered Good (Code Green); when it reaches over 200, the air is considered Very Unhealthy for everyone to breathe (Code Purple). Other AQI designations—Moderate (Code Yellow), Unhealthy for Sensitive Groups (Code Orange), and Unhealthy (Code Red)—vary in threat level, with children, pregnant people, and other vulnerable groups at higher risk of health impacts than the general population.
There’s a separate AQI for each of multiple pollutants regulated by the Clean Air Act, including ground-level ozone (a.k.a. smog) and particle pollution (a.k.a. soot). The AQI number you see on your smartphone’s weather app is for the pollutant that is most impacting air quality at any given moment.
EPA recently released updates to the AQI for particle pollution based on new updates to the National Ambient Air Quality Standards (NAAQS) for fine particle pollution for the first time in over a decade. The NAAQS directly inform the AQI. According to EPA, many places can now expect to see more days in the Moderate (Code Yellow) category because of the changes in the AQI breakpoints.
What the AQI doesn’t yet reflect is emerging evidence about differences in the level of harm between air pollution from burning fossil fuels and air pollution from wildfires. Recent studies suggest that wildfire smoke may be far more dangerous than air pollution generated by burning fossil fuels, and because of climate change, our level of exposure to wildfire smoke is likely to dramatically increase.
To learn more about the updates to the AQI and how parents and caregivers should be thinking about air pollution and children’s health, we caught up with pediatrician and Stanford professor Lisa Patel. Dr. Patel is a leading expert on climate change and children’s health, and you might remember the op-ed she co-authored for the New York Times last July about the impact of wildfire smoke on little lungs.
This interview has been edited for length and clarity.
From your perspective as a pediatrician and a parent, how are you viewing the updates to the Air Quality Index?
Some of our evidence is starting to show that wildfire smoke is actually more toxic than the regular air pollution we breathe because of fossil fuels. My son was born in 2018, and for three of the five years of his life, he’s had multiple days to weeks of wildfire smoke exposure. What I personally do as a pediatrician and an environmental scientist, especially because I live in a place with frequent wildfire smoke, is to treat a Code Yellow day as a day to limit our time outdoors, understanding that for my son, more or less, wildfire smoke is going to be a chronic exposure for him. And knowing that these first years are critical parts of his life development. Those are the individual actions I have taken as a parent, although our public health guidance is different. And that’s because I’ve seen enough of the data to be concerned.
Is there a need to update guidance related to air quality and children’s activities, such as the guidance provided in charts like these?
Unfortunately, we’re living a natural experiment, the concrete results of which we will not know for 5 to 10 years. This makes it difficult to develop strong, evidence-based public health guidelines for everyone to follow, and it’s a difficult balance for EPA. We also need to balance the fact that being outside is good for kids. How do we balance the fact that we have pretty good indications of what this chronic exposure to air pollution is going to mean for our kids and yet the science is not deterministic yet? We don’t want to trap kids inside when we know there is a cost when children spend too much time indoors.
For what we understand the current science to be, the new EPA air quality guidelines are reasonable. But if a parent decides to take more precautions in terms of air quality, I think that is also an entirely reasonable approach, and one that I have taken myself.
What would you tell parents in your practice about keeping kids safe on Moderate (Code Yellow) days?
I’ll say that in the Yellow category, I think it’s a good idea not to treat it as a totally normal day. If you’re planning on being outside for a long hike, maybe make it a shorter one. Reduce your time outdoors. Knowing that kids are more vulnerable, knowing that pound for pound, kids are breathing in more of that toxic air pollution, knowing that we’re starting to erase those air quality gains, and particularly if you live in a place with wildfire smoke, don’t treat the Yellow day like a normal one.
[Note: On days when the AQI is designated Code Orange, Red, Purple, or Maroon, EPA advises that all children and other vulnerable groups limit time outdoors, particularly time involving physical exertion. Wearing an N95 mask can also help limit exposure to air pollution. Moms Clean Air Force created a flyer you can use in your community to help spread awareness about how to keep children safe when the air quality is poor. Download the flyer in English and Spanish.]
What else can parents do to keep children safe from unhealthy air?
Indoor air quality matters too. If possible, parents can work on getting gas stoves out of their homes to ensure cleaner indoor air. Other options include investing in portable HEPA filters or even making a DIY box filter if they can’t afford to buy one.
We know that air pollution and brain inflammation are linked. What are you learning about wildfire smoke and children’s brain health?
There’s data that shows links between air pollution and risks for depression and anxiety. A paper that just came out shows that air pollution is one of the top three risks for dementia.
Research has also found that there is particle pollution in a developing fetus’s brain, lungs, and liver—what does that mean? We don’t know yet what that early exposure means, beyond that the window of time that we are exposed to this pollution is longer than we thought. In terms of the detrimental effects of air pollution, it has to do with how long you’re exposed to it and how much you’re exposed to it, so putting those two things together, if our exposure starts basically from the time you’re in utero, that’s a much longer exposure window than any of us fully understood or comprehended.
What would you like to see happen in the next year or so in terms of public advocacy around air quality and children’s health?
I wish that there was specific air quality guidance for children and pregnant people. There are a number of vulnerable populations, and EPA tries to address the entire population to do their best to serve a public health role. But it’s important to create child-specific alerts here, because children are vulnerable in multiple ways. Exposure to wildfire smoke is going to be their life moving forward. And so we need to be a little bit more conservative and cautious with them to begin with. The public does not have the awareness of what air pollution means for their health, thanks to the fossil fuel industry and all they’ve done to try to obstruct the fact that this is a really important marker for children’s health.
There’s a lot of argument to be made for putting children’s health front and center, especially understanding that kids are inheriting a lot of this increasing pollution. We should be investing in understanding how these threats are going to play out for children and the adults they will become.
Learn more about Moms’ work on smog and soot pollution.