THURSDAY, May 30, 2019 (HealthDay News) -- Recent forest fires in the western United States have put a spotlight on a fire-management approach called controlled burning. Health researchers are weighing in, too, saying controlled burns pose less of an air pollution risk to children than wildfires.
Controlled, or prescribed, burns are done to reduce levels of material that can feed wildfires.
"We know that there's some public opposition to doing prescribed burning," said study lead author Dr. Mary Prunicki, instructor of medicine at Stanford University. "It's our feeling that prescribed burning, because it's so controlled, may expose people to fewer health effects than wildfires."
For the study, researchers analyzed blood samples from two groups of children, ages 7 and 8, in Fresno, Calif. The investigators were assessing levels of immune markers that indicate air pollution exposure.
One group of 32 children had been exposed to smoke from a 553-acre prescribed burn in March 2015. A second group of 36 children had been exposed to smoke from a 415-acre wildfire in September 2015.
Both fires were about 70 miles away from Fresno, and the blood samples were collected within three months of each fire.
The researchers also checked air pollution levels recorded at four monitoring stations in Fresno and estimated air pollution levels at the children's homes during the fires.
Blood samples were also taken from a third group of 18 children who lived in the San Francisco Bay Area and had not been exposed to wildfire or prescribed-burn smoke.
Levels of immune markers associated with air pollution exposure were higher among children exposed to the wildfire smoke than among those exposed to the prescribed-burn smoke, according to the study.
The researchers noted that Fresno regularly has high air pollution levels due to its topography, traffic and local agriculture.
"This study suggests that exposure to wildfire smoke is detrimental above and beyond poor air quality," Prunicki said in a university news release.
The study results were published May 30 in the European Journal of Allergy and Clinical Immunology.
The American Lung Association has more on children and air pollution.