Toxic particles from air pollution have been found in the lungs, livers and brains of unborn babies, long before they have taken their first breath. Researchers called it “groundbreaking” discovery was “very worrying” because the gestation period of fetuses is the most vulnerable stage of human development.
Thousands of black carbon particles were found in every cubic millimeter of tissue, which were inhaled by the mother during pregnancy and then passed through the bloodstream and the placenta to the fetus.
It was already known that dirty air was strongly correlated with increased miscarriages, premature births, low birth weights and disturbed brain development. But the new study provides direct evidence of how that damage can be caused. The scientists said the pollution can cause lifelong health effects.
The particles are made from soot from burning fossil fuels in cars, homes and factories and cause inflammation in the body as well as carrying toxic chemicals. The research was conducted with non-smoking mothers in Scotland and Belgium, in places with relatively low air pollution.
“We have shown for the first time that black carbon nanoparticles not only enter the first and second trimester placenta, but also find their way into the organs of the developing fetus,” said Prof Paul Fowler, at the University of Aberdeen in Scotland. .
“What is even more worrying is that these particles also end up in the developing human brain,” he said. “This means that it is possible for these nanoparticles to directly interact with control systems within human fetal organs and cells.”
Prof Tim Nawrot at Hasselt University in Belgium, who co-led the study, said: “Air quality regulations need to recognize this [air pollution] transmission during pregnancy and act to protect the most sensitive stages of human development.
He said governments are responsible for reducing air pollution, but people should avoid busy roads if possible.
Air pollution particles were first detected in placentas in 2018 by Prof Jonathan Grigg at Queen Mary University of London and colleagues. He said: “The new study is very good – they have shown convincingly that the particles then get into the fetuses.
“Seeing particles get into the brains of fetuses raises the stakes because this has potentially lifelong consequences for the child,” Grigg said. “It’s worrying, but we still don’t know what happens when the particles lie in different places and slowly release their chemicals,” meaning that further research is needed.
A comprehensive global review in 2019 concluded that air pollution can damage every organ and virtually every cell in the human body. Tiny particles have also been found to cross the blood-brain barrier and billions have been found in the hearts of young city dwellers. More than 90% of the world’s population lives in places where air pollution exceeds World Health Organization (WHO) guidelines, causing millions of premature deaths each year.
The new study, published in the journal Lancet Planetary Health, found air pollution particles in every sample of lung, liver and brain tissue examined, as well as in umbilical cord blood and placentas. The concentration of particles was higher if the mother lived with higher levels of air pollution compared to others in the study.
The 36 fetuses examined in the Scottish part of the study were from voluntary terminations of normally progressing pregnancies between seven and 20 weeks of gestation. “The findings are particularly concerning because this window of exposure is key to organ development,” said the scientists. In Belgium, after 60 healthy births, 60 healthy births were taken.