Underestimating Wildfire’s Effect
The specific effects of wildfire pollution on the skin are less clear, in part because every wildfire is unique depending on what it burns (building materials? trees? bushes?), its intensity and its temperature. The most toxic compounds are created at the highest temperatures, Dr. Valacchi said.
(This is also true of cigarettes. There is no healthy way to smoke, but worst is if you smoke so quickly the ash doesn’t fall. “You have a very high combustion temperature, and it creates very, very, very carcinogenic compounds,” he said.)
Researchers for the eczema and wildfire study chose to focus on that disease because people afflicted have an impaired skin barrier, meaning they would be more likely to have a reaction to smoke, Dr. Wei said. Some 7 percent of adults and 15 percent of children in the United States have eczema, but it’s not yet clear how this translates to the rest of the population since it’s not known if the incidence and severity of skin disease simply intensifies as pollution does, or if there’s a threshold of pollution at which the skin barrier just completely fails, she said. (Unlike long-term exposure to air pollution from cars and industry, wildfires are generally short but extremely intense exposure to hazardous air, Mr. Fadadu said.)
In the study, visits to the dermatology clinic for itch were up significantly during the roughly two weeks of the fire in November, and 89 percent of adult patients had no previous diagnosis. (During the same time period in previous years, some 50 percent of patients with eczema had no previous diagnosis.) Researchers don’t know if these people had subclinical eczema and the fire “unmasked it,” Dr. Wei said, or if “these were normal folks who actually had symptoms of eczema from the fire.”
Either way, Dr. Misha Rosenbach, an associate professor of dermatology at the University of Pennsylvania and a chair of the Climate Change and Environmental Affairs Expert Resource Group of the American Academy of Dermatology, said the impact of wildfires on skin is very likely much greater than what we know now. He praised the eczema study but said it probably underestimates wildfires’ effects — most people with rashes tend to go to emergency rooms or primary care doctors, not dermatology clinics, which were the study’s data set.
Also, the study took place in San Francisco, 175 miles from the source of the fire. “We’ve had many days on the East Coast where the air quality is the worst it’s ever been because of the West Coast fires,” he said.