Scientists have found the first evidence that particles of air pollution travel through the lungs of pregnant women and settle in their placenta.
Toxic air is already strongly linked to damage in fetuses, but how the damage has been done is unknown. The new study with mothers who lived in London revealed soot particles in the placenta's of each of their babies and researchers say it is quite possible that the particles also end up in the fetuses.
"It is a worrying problem – there is a huge association between air pollution that a mother inhales and its effect on the fetus," said Dr. Lisa Miyashita, at the Queen Mary University of London, one of the research teams. "It is always good if it is possible to take less contaminated routes if you are pregnant – or if you are not pregnant." I avoid busy roads when I walk to the station. "
A series of previous studies have shown that air pollution significantly increases the risk of preterm birth and low birth weight, leading to lifelong damage to health. A comprehensive study of more than 500,000 deliveries in London, published in December, confirmed the link and led doctors to say that the consequences for many millions of women in polluted cities around the world are "something that is approaching a public health disaster" .
Scientists increasingly find that air pollution leads to health problems far beyond the lungs. In August, research revealed that air pollution causes a "huge" reduction in intelligence, while in 2016 toxic nanoparticles from air pollution were detected in the human brain.
The new study examined the placenta's of five non-smoking women who all delivered healthy babies. The researchers isolated macrophage cells, which are part of the immune system of the body and cover harmful particles such as bacteria and air pollution.
Using an optical microscope, they found 72 dark particles under 3,500 cells and then used a powerful electron microscope to examine the shape of some particles. They were very similar to the soot particles in macrophages in the lung, which catch many – but not all – particles.
Although further analysis is needed for final confirmation, Dr. Miyashita said: "We can not think of anything else it could be, it is very clear to us that it is sooty black." Previous experiments have shown that particles inhaled by pregnant animals by the bloodstream in placenta & # 39; s going.
"We do not know if the particles found can also pass into the fetus, but our evidence suggests that this is indeed possible," said Dr. Norrice Liu, also at Queen Mary University of London and part of the team. "We also know that the particles do not have to enter the body of the baby to have a negative effect, because if they have an effect on the placenta, this will have a direct impact on the fetus."
The research will be presented on Sunday at the international conference of the European Respiratory Society (ERS) in Paris. "This research suggests a possible mechanism of how babies are affected by pollution while being theoretically protected in the womb," said Prof. Mina Gaga, who is ERS president and at Athens Chest Hospital in Greece.
"This should make doctors and the public aware of the harmful effects of air pollution in pregnant women," she said, noting that damage to fetuses can occur even under the current pollution limits of the European Union. "We need a stricter policy for cleaner air to reduce the impact of pollution on health globally, because we already see a new population of young adults with health problems."
UNICEF director Anthony Lake recently warned of the danger of air pollution for babies: "Not only do pollutants pollute the developing lungs of babies, they can also permanently damage their developing brain – and thus their future."
Separate research, also presented at the ERS congress, showed that children with early onset and persistent asthma performed much less well in education than those without the condition. Asthma in children has long been associated with air pollution.
The study, conducted in 20 years in Sweden, showed that children with asthma were three and a half times more likely to leave school at the age of 16 with only basic education and twice as likely to graduate.
Dr. Christian Schyllert, at the Karolinska University Hospital in Stockholm, said: "This study suggests [these] children have a worse chance of life when it comes to their education and their future jobs. "He said that one possible reason could be that children with asthma are known to have a primary school.