Exposure to wood smoke can have different effects on the respiratory immune systems of men and women – effects that may be obscured when data from men and women are lumped together, according to a study published today in the American Journal of Respiratory and Critical Care Medicine by scientists at the UNC School of Medicine and the UNC Gillings School of Global Public Health.
The scientists exposed men and women volunteers to wood smoke or filtered air prior to inoculating them with a standard dose of the live-attenuated influenza virus vaccine, which causes a natural, yet mild, immune response in the nasal passages. They then later discovered that the men exposed to wood smoke had significantly higher markers of an inflammatory response in cells that line the nasal passages relative to men exposed to filtered air. By contrast, for women, the wood smoke exposure appeared to lower markers of the inflammatory response. When the researchers averaged out the data from men and women, as these sorts of exposure studies typically do, the analysis gave the false impression that the wood smoke had almost no effect on the immune response to the live-attenuated influenza virus vaccine.
“The upshot is that we really need to consider sex-specific effects when studying wood smoke and other environmental pollutants that threaten public health,” said senior author Ilona Jaspers, PhD, a professor of pediatrics in the UNC School of Medicine and director of UNC-Chapel Hill’s Curriculum in Toxicology & Environmental Medicine.
Wood smoke is among the most ancient environmental pollutants, and is still considered a significant cause of sickness and death today. Researchers estimate that about 40 percent of the modern human population, roughly 3 billion people, are chronically exposed to smoke from burning wood and related “biomass” combustibles, such as leaves, crop stalks, and dung. Wood smoke contains dozens of known toxins, and epidemiological studies have linked biomass exposures to chronic obstructive pulmonary disorder (COPD) in women who have never smoked and lung cancer in male firefighters. Wood smoke exposure is also expected to become more common as the frequency of wildfires increases.
Read more at University of North Carolina Health Care
Photo credit: Pexels via Pixabay