Air pollution particles can enter fetal organs as they develop in the womb, potentially disrupting development, a study suggests.
Academics from the University of Aberdeen and the University of Hasselt in Belgium have found evidence of black carbon particles, also known as soot particles, in the blood of the umbilical cord.
In turn, this suggests that they can cross the placenta.
Scientists say air pollution is linked to “premature birth, low birth weight babies and impaired brain development.”
The researchers warn that key organ development occurs as the baby develops in the womb – the particles can be seen in the first trimester of pregnancy.
During the study, they examined 60 mothers and their babies in Aberdeen and the Grampians region of Scotland.
They also analyzed tissue samples from 36 fetuses aborted between 7 and 20 weeks of gestation.
Soot particles are present in all mothers and newborns — as well as in the liver, lungs and brains of aborted fetuses.
All tissue samples analyzed contained black carbon particles.
Black carbon is one of many particles and gases emitted when diesel, coal and other biomass fuels are burned.
The number of particles found depends on the amount of air pollution the mother was exposed to during pregnancy.
This is said to be the first time black carbon nanoparticles have been found in a developing fetus.
Read more: Government proposes legal targets on air pollution and wildlife
Writing in The Lancet Planetary Health, the study authors wrote: “We found that carbon-containing air pollution particles inhaled by the mother can cross the placenta and then be transferred to human fetal organs during pregnancy.
“These findings are particularly concerning because this window of exposure is critical for organ development.”
Professor Tim Norot, from Hasselt University, said: “We know that exposure to air pollution during pregnancy and infancy is associated with stillbirth, preterm birth, low birth weight babies and impaired brain development, with consequences that last a lifetime.
“This means that air quality regulation should recognize this shift during pregnancy and act to protect the most vulnerable stage of human development.”
Professor Paul Fowler from the University of Aberdeen added: “We are all concerned that if nanoparticles get into the fetus, they may directly affect the development of the fetus in the womb.
“We showed for the first time that black carbon air pollution nanoparticles enter not only the placenta in the first and second trimesters, but also the developing fetal organs, including the liver and lungs.”