Air pollution has the potential to travel from a pregnant woman's lungs to the fetal side of the placenta, according to a new study.

Researchers at Hasselt University in Belgium in a study reported in Nature Communications found sootlike black carbon, a type of particle pollutant, on placentas donated by new mothers. The placenta is a temporary organ that acts as a natural barrier between a mother and the fetus during pregnancy.

ADVERTISEMENT

The study is the first that found particles accumulated on the fetus's side of the placenta, near the site of the formation of the umbilical cord.

The researchers studied placentas from 10 mothers who lived near major roads, as well as 10 placentas from donors who lived farther from busy streets. The mothers who had been exposed to higher levels of air pollution during pregnancy were found to have the highest levels of particles in the placenta.

The discovery is “a potential mechanism explaining the detrimental health effects of pollution from early life onwards,” the researchers said.

Combustion-related particle matter is associated with lower birth weight, preterm birth and intrauterine growth restriction, they noted.

Dr. Yoel Sadovsky of the University of Pittsburgh Medical Center, a placenta expert who wasn’t involved in the new research, told The Associated Press that there is no proof of soot reaching the fetus or causing ill effects.

Sadovsky said, however, that just finding the particles in the placenta “is important.”

“The next question would be how much of these black carbon particles need to be there to cause damage,” Sadovsky said.