This story originally appeared in High Country News and is part of the Climate Desk collaboration. The more researchers learn about the fire’s smoke, the more alarming the picture becomes. Smoke contains microscopic particles known as PM 2.5 because PM (particulate matter) is 2.5 microns or less—small enough to easily move into the lungs and then into the bloodstream. Researchers have linked the particles in fire smoke to the risk of stroke, heart disease, respiratory disease, lung cancer, and other serious conditions. And the harmful effects do not stop there. 2024 is a banner year for research into fire smoke and its effects on health, from brain function to fertility. While much remains to be learned, fire smoke is considered more insidious compared to other sources of air pollution; smaller particle sizes, intermittent spikes, and higher concentrations of inflammatory compounds make them more dangerous. New findings this year are troubling. But the more we learn about smoke, the better we can protect ourselves from it, whether we live hundreds of miles away from a fire or face it head-on the way wildland firefighters do. Research underscores the need for a number of changes, including better indoor air filtration systems in homes, hospitals, schools, and nursing homes, and clean air centers for people who have nowhere else to breathe healthy air. Meanwhile, respirators for wildland firefighters are currently being tested by the federal government. We must also reduce smoke pollution at these sources by taking measures to reduce the risk and intensity of fires, such as prescribed fires. Here are some of the biggest advances in scientists’ understanding of wildfire smoke by 2024: New Estimates Predict 125 Million Americans Will Face Unhealthy Air from Wildfires by 2054 Wildfire smoke has eliminated air quality improvements in recent years, a trend that is expected to continue . Millions more will be exposed to unhealthy air in the coming years, according to models released by the First Street Foundation in February. It is estimated that by 2054, more than 125 million Americans each year will experience “red” air quality, which is considered an unhealthy level by the Environmental Protection Agency – a 50 percent increase from 2024. California’s Central Valley will experience the worst, with Fresno and Tulare County likely to face three months of unhealthy air each year, according to the study.Smog Can Hinder Fertility Treatment through the Labor Day weekend in 2020 covered Oregon with the worst air quality in the world at that time. 10 days or more of smoky air affects everyone, especially patients undergoing in vitro fertilization treatment, or IVF. Researchers at Oregon Health & Science University studied 69 patients who received ovarian stimulation and IVF treatment for six weeks after the wildfires. The study, published in the journal Fertility and Sterility in May, found that patients exposed to fire smoke produced fewer blastocysts – groups of cells that can develop into embryos – than those not exposed. Most of the patients were still pregnant, but the study’s lead author said he was concerned about how the smoke might affect fertility treatments. He told the Idaho Capital Sun that, as an extra precaution, fertility providers may want to delay IVF or embryo transfers for higher-risk patients during poor air quality. Bridal Falls in Yosemite National Park in Yosemite, California, as smoke from the Washburn Fire blankets the valley on July 11, 2022. Photo: Getty Images . A new study published in the journal Science Advances in June found that fine particulate matter in smog caused 52,500 to 55,700 premature deaths from 2008 to 2018 in California. According to the authors, this is the first long-term study to assess deaths caused by years of increased exposure to fire smoke in a country that, like other Western countries, experiences more frequent and more severe forest fires. Mental Health Researchers at the University of Colorado Boulder found that wildfire smoke can increase the risk of mental health challenges in adolescents. The study, published in the journal Environmental Health Perspectives in September, analyzed data from 10,000 preadolescents who participated in the largest long-term study of brain development and child health in the United States, according to the university. Every additional day that children were exposed to “unsafe” air quality readings in 2016 increased their likelihood of experiencing symptoms of depression and anxiety—even up to a year later. Years of Firefighting Can Cause Neurodegenerative Diseases. , of course. But in a controlled setting, they can provide valuable insight into human health consequences. Researchers who exposed rats to the same amount of smoke as what a wildland firefighter would inhale over a 15- to 30-year career found that they were less likely to develop brain disease than rats that were not exposed. The animal’s gene profiles matched patterns that showed long-term damage similar to the effects of Alzheimer’s, Parkinson’s, Huntington’s, and other neurodegenerative diseases. While the researchers could not prove that the smoke was a direct cause of the increased risk of disease, lead author Adam Schuller told Boise State Public Radio that firefighters should be aware of the impact of a long career in firefighting on the human brain. Smoke Linked to Dementia Breathing in air pollution particles has been linked to an increased risk of dementia. Now, researchers say, wildfire smoke may pose a greater risk than any other source of pollution. An analysis of more than 1.2 million people in Southern California found that exposure to wildfire smoke over a long period of time—three years, in this study—was associated with a higher risk of dementia diagnosis. According to a study, published in the journal JAMA Neurology, the probability of a diagnosis of dementia increases by 18 percent for every microgram per cubic meter of increased fire pollution over three years, a relatively small amount. For comparison, the average PM 2.5 exposure for census tracts near the 2018 Camp Fire in California was 1.2 micrograms per cubic meter between 2006 and 2020, up from 310 micrograms per cubic meter during the actual fire.
