Prenatal exposure to ultra-fine particles increases a child’s risk of asthma, study finds

Factors from air pollution to drug use can shape fetal and childhood development, but the new study is one of the first to specifically link ultra-fine particle exposure in utero to a higher probability of asthma development in childhood.

Ultra-fine particles (UFPs) are less than 0.1 microns in diameter; a typical human hair is about 50 to 80 microns. They can come from a number of sources, including car exhaust, industrial processes, burning wood or coal, and airplanes taking off and landing. Unlike other air pollutants and slightly larger particles, they aren’t regulated by the Environmental Protection Agency — and their minuscule size amplifies their danger. 

The study found that as the modeled UFP exposure during pregnancy doubled, the odds ratio for incident asthma was 4.28 (1.41–15.7). The highest risk of asthma occurred in female offspring of mothers exposed to higher UFPs during late pregnancy.

Access abstract here: https://www.atsjournals.org/doi/pdf/10.1164/rccm.202010-3743OC