In utero exposure to tiny air pollution particles is linked to asthma in preschoolers

Women who were highly exposed to ultra-fine particles in air pollution during their pregnancy were more likely to have children who developed asthma, according to a new study. This is the first time asthma has been linked with prenatal exposure to this type of air pollution, which is named for its tiny size and which is not regulated or routinely monitored in the United States.