Wildfires Are Causing More Bad Air Days. Is the Pollution Putting Californians at Higher Risk for Disease?

In California, people are familiar with the immediate health impacts of a wildfire: asthma, coughing, respiratory illnesses. But as the state faces an increasing number of smoky days, researchers are beginning to look at the long-term effects.

According to one analysis by the Stanford Environmental Change and Outcomes Lab, one month of elevated smoke exposure led to 3,000 excess deaths between August and September of 2020. The estimate, based on Medicare data, only captures individuals in California 65 years and older, making the actual number likely much higher.

At the same time, wildfire smoke is affecting the unborn. The Stanford lab estimates wildfire smoke is associated with nearly 7,000 preterm births per year in California, with a 3.4% increase in risk for every week a mother is exposed (one week is the average number of smoky days per year in California). While the study did not record any maternal-child deaths, premature babies are at higher risk of developmental delays, learning disabilities, and social problems later in life. “Not every child catches up, so some of the preterm births ended up having really long-lasting health impacts just because they weren’t able to fully develop during the pregnancy,” said Sam Heft-Neal, a co-author of the study and member of the lab.

In addition, caring for a premature baby can be expensive. “We’re much, much better at keeping preterm babies alive than we used to be, but it’s a really costly process and so any parents that have preterm births have to deal with really high bills for all the care that’s required.”

What’s less clear is whether wildfires directly cause disease. Several factors, such as housing situation, socioeconomic status, and access to health care, all play a role in determining a person’s health. And researchers say it’s hard to take all these elements into account when they draw conclusions. For that reason, it’s difficult to attribute a person’s health outcomes to any one factor, including wildfire smoke. “People who are exposed to 10 years of exposure are systematically different from the people who are not,” explained Heft-Neal.

But researchers do know who’s most likely to be affected – and it’s not necessarily intuitive. “There’s pretty clear evidence low-income and non-white households are more likely to be exposed to pollution overall,” said Heft-Neal, “but when you look at wildfire smoke, you actually see a quite different pattern.” Unlike other types of pollution, wildfires are more likely to affect white households simply because “a lot of the rural populations in Northern part of the state are primarily white and that’s where most of the fires are.”

While those with means can afford to move away from polluting power plants or highways, wildfires often erupt in California’s most affluent regions. During the 2020 wildfire season, for example, the Bay Area had some of the worst air quality in the world. “At times [wildfire smoke] covers the entire state and wealthy neighborhoods in San Francisco and Marin can get hit really hard…whereas they rarely get hit with other types of pollution.”

That being said, low-income people living in these smoke-affected areas have a much harder time insulating themselves than their wealthy neighbors. “Income definitely impacts the ways that communities are facing this issue,” said Pedro Toledo, the CEO of Petaluma Health Centers, which serves low-income and uninsured individuals in Sonoma County. Many of Toledo’s patients are farmworkers who work outside during some of the smokiest days of the year. “Harvest starts in September and October here in Sonoma County and that’s wildfire season so you have to be out in fields.” Toledo has seen a jump in respiratory illnesses among these patients: Prescriptions for inhalers are “through the roof at this point, much more than we’ve ever prescribed.”

But even for those who don’t work outside, reducing exposure is highly dependent on socioeconomic status. Many of Toledo’s patients “don’t have the discretionary income to purchase air filters,” which can significantly improve indoor air quality. Others live in homes without air conditioning, which means they are more likely to keep their windows open, letting in polluted air. These kinds of behaviors have a significant impact on how much smoke someone is exposed to, regardless of the air quality outside. According to one study published in NCBI, personal interventions, like closing the windows and using an air filter, have been found to reduce a person’s smoke exposure by up to 80%. “Even for a given level of outdoor exposure, you can have very, very different levels of indoor exposure,” explained Heft-Neal. “Forcing people to individually deal with pollution, I think, is potentially a really unfair policy because it may be just placing more of the burden on the disadvantaged households.”

At the same time, health care providers are conflicted about how to help patients cope with the smoky air. Toledo says his health center has been prescribing inhalers to patients that have never had asthma before just in case a wildfire triggers an attack. The idea is to prevent them from having to go to the ER, he says. But with wildfires, that may not be a long-term solution: “Medicating isn’t the answer, the answer is having cleaner air.”

Since August 2021, Direct Relief has sent 505 shipments of medical aid valued at more than $2.25 million to 193 health facilities treating patients in fire-affected areas across the United States.