Black carbon particles from air pollution can cross the placenta during pregnancy, potentially impacting a growing fetus, according to the findings of new research.
In a study published this month in the journal Nature Communications, researchers from Belgium indicate that black carbon, which is a common byproduct of fossil fuel combustion, was found in every mother’s placenta after giving birth.
The researchers evaluated 28 women who had just given birth at East-Limburg Hospital, in Genk, Belgium, taking high-resolution images of placenta tissue following delivery. In each case, the placenta was retrieved within 10 minutes after delivery, with five of the women giving birth prematurely, and the rest carrying their child to term.
Black carbon particles were detected in the placenta of all the participating mothers.
The particles are part of carbon air pollution, and can also absorb other toxic compounds, such as heavy metals and benzene, which are known cancer causing agents.
This is the first study to show carbon air pollution particles definitively reach the fetus and cross the placenta barrier during pregnancy, although others have speculated as much.
In a study published last year, researchers suggested air pollution could penetrate the placenta during pregnancy, but could not show cause and effect or a full effect of the pollution on the growth of the child.
The new research indicates that air pollution can cross the placenta during pregnancy, and may threaten the health of the developing fetus.
According to the findings, there was a link between the amount of black carbon found and the mother’s residential air pollution exposure during pregnancy. The placentae of women who lived in more heavily polluted areas had higher levels of black carbon particles than those who lived in less polluted areas.
Researchers said it is unclear if once the particles cross the placenta the exposure conclusively harms fetal development, but the potential is there. More research is needed to further investigate the effects of pollution once it has crossed the placenta.
Harmful air pollution side effects
Prior studies have shown a link between air pollution exposure during pregnancy and side effects during a child’s early years. However, while each study showed a compelling link between air pollution and harm to the child, the studies didn’t show a direct cause and effect.
In another study published earlier this year, researchers linked fetal exposure to infant heart damage.
Another study published in 2018 showed a correlation between pregnancy exposure to air pollution and heightened risk of miscarriage, while yet another study linked air pollution exposure during pregnancy to increased risk of a child developing autism.
The key finding of this latest research is that what a mother’s environment contains is also transferred to the fetus. This has long-term implications.
Ingestion of pollution can also increase a person’s infection risk and lead to placental inflammation, which can lead to low birth weight, preterm birth, and cognitive impairment
The placenta delivers nutrition and oxygen to a growing fetus and also offers some protection and barrier from toxins.
“Our finding that black carbon particles accumulate on the fetal side of the placenta suggests that ambient particulates could be transported towards the fetus and represents a potential mechanism explaining the detrimental health effects of pollution from early life onwards,” the researchers warned.