According to an article published by National Geographic, a new study has found more evidence that the air pollution created by the fall of the World Trade Center towers in Lower Manhattan during the September 11 terrorist attacks negatively impacted newborns whose mothers were exposed to the hazardous dust.

National Geographic says the study, which was published in the Journal of Human Resources, adds to a body of research showing that exposure to air pollution in the womb can have adverse health effects on newborns, and those effects can play out over the course of a lifetime.

Researchers studied 1.2 million births in New York City birth records from 1994 to 2004 and focused on data from women were the most exposed to the dust cloud.

Results found that women in their first trimester during 9/11 had more than double the probability of premature delivery. The study also showed an increase in low birth weights for newborns.

“The pregnancy conditions really matter for later economic outcomes and for long-term human development and economic success,” researchers told National Geographic.