Air pollution particles can enter the organs of fetuses as they develop in the womb, potentially harming development, a study has found.
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 umbilical cord blood.
This, in turn, shows that they can cross the placenta.
Air pollution has been linked to “premature birth, low birth weight babies and impaired brain development”, scientists have said.
Development of key organs occurs as the baby grows in the womb – and the particles can be seen in the first trimester of pregnancy, the researchers warned.
During their study, they examined 60 mothers and their babies in Aberdeen and the Grampian region of Scotland.
They also analyzed tissue samples from 36 fetuses aborted between seven and 20 weeks gestation.
Soot particles were present in all mothers and newborns, as well as in the livers, lungs and brains of aborted fetuses.
All tissue samples analyzed contained black carbon particles.
Black carbon is one of many particles and gases emitted during the combustion of diesel, coal and other biomass fuels.
The number of particles found depended on the amount of air pollution the mother was exposed to during pregnancy.
This is said to be the first time that black carbon nanoparticles have been found in developing fetuses.
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Writing in the journal Lancet Planetary Health, the study authors wrote: “We found that carbonaceous air pollution particles inhaled by the mother can cross the placenta and then translocate to human fetal organs during gestation.
“These results are particularly concerning because this window of exposure is critical for organ development.”
Professor Tim Nawrot, from the University of Hasselt, said: “We know that exposure to air pollution during pregnancy and infancy has been linked to stillbirth, premature birth, babies low weight and impaired brain development, with lifelong consequences.
“This means air quality regulation should recognize this transfer during gestation and act to protect the most sensitive stages of human development.”
Professor Paul Fowler, from the University of Aberdeen, added: “We were all concerned that if nanoparticles enter the fetus, they could directly affect its development in the womb.
“What we have shown for the first time is that black carbon air pollution nanoparticles not only enter the first and second trimester placenta, but also end up in the organs of the developing fetus, including including liver and lungs.