In one recent study, Dr. Aguilera and his colleagues enrolled 186 women who were 20 weeks pregnant and lived in Fresno, one of the nation’s most highly polluted cities due to its topography and exposure to wildfires and agricultural pollutants. They found that T-helper immune cells were influenced by exposure to fine particulate matter, nitrogen dioxide, carbon monoxide, and polycyclic aromatic hydrocarbons. The findings show the negative effects of air pollution exposure during pregnancy and the need for more epigenetic studies. (Clin Epigenetics. 2022;14:40) “It throws off the immune system,” said Dr. Aguilera. “Patients will have fewer of the beneficial immune cells that keep your immune system in balance.”
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August 2022Pollen and CRS
Another aggravator of rhinologic conditions is pollen, and this topic is looking bleak as well. University of Michigan researchers assessed how temperature and precipitation changes affect pollen season and grass season length, as well as pollen emissions. Based on these patterns, they said, models predict that pollen emissions will increase by 200% by the end of the century, increasing the likelihood of seasonal allergies (Nat Commun. 2022;13:1234).
Climate change isn’t something in the future or in distant parts of the world—it’s here with us now. And in every breath that we take in the spring, we’re inhaling climate change-driven exacerbations of pollen. —William Anderegg, PhD
William Anderegg, PhD
In findings published in 2021, researchers found that pollen seasons have lengthened by 20 days and pollen concentrations have increased by 21% across North America, and that these concentrations were strongly correlated with global warming. Human influences on the climate system, they determined, contributed about 50% of the trend in the pollen season length and about 8% in the trend of increasing pollen concentrations (Proc Natl Acad Sci USA. 2021;118:e2013284118). “It’s a really clear example that climate change isn’t something in the future or in distant parts of the world—it’s here with us now,” said William Anderegg, PhD, associate professor of biological sciences at the University of Utah in Salt Lake City and the lead author of the study. “And in every breath that we take in the spring, we’re inhaling climate change-driven exacerbations of pollen.”
Researchers in Belgium and Sweden looked at 12 patients with grass pollen-sensitized CRS, 12 grass pollen-allergic rhinitis patients, 12 patients with CRS with nasal polyps, and 12 controls. On provocation testing with grass pollen, the test was positive in six of 12 patients with CRS with nasal polyps who were grass pollen-sensitized, with another four showing allergic symptoms not rising to test positivity. This contrasted with all the patients with allergic rhinitis having a positive test, one in the control group with a positive test, and two in the nonsensitized CRS with nasal polyps group having a positive test. “These results,” researchers wrote, “show that allergen exposure induces an attenuated clinical response in patients with CRS with nasal polyps and sensitization to grass pollen as compared with grass pollenallergic rhinitis patients” (Clin Exp Allergy. 2016;46:555-563).