Babies in womb suffering effects of air pollution
The full extent of the threat caused by air pollution has been revealed after research by Belgian scientists found that unborn babies experience direct exposure to carbon particles while still in the womb.
Scientific journal Nature Communications published the research, carried out on the placentas of 25 non-smoking women in the town of Hasselt, whose pollution levels are above the World Health Organization, or WHO, limit, but well below those of the European Union.
In each, carbon particles were found. In mothers who lived near main roads, there was an average of 20,000 nanoparticles per cubic millimeter in the placenta. For those further away, the figure was halved.
"This is the most vulnerable period of life. All the organ systems are in development. For the protection of future generations, we have to reduce exposure," said the study's leader, professor Tim Nawrot, from Hasselt University.
It has long been known that there is a connection between dirty air and the increased likelihood of miscarriages, premature births and children with low birth weights.
Previously it was thought that the mothers' inflammatory response may be the cause, but these results are the first to show that particles penetrate the placental barrier, and suggest it may be the presence of these particles that does the damage.
The researchers also found high levels of black carbon in the urine of school children, showing how particles can move around the body.
"It is really difficult to give people practical advice, because everyone has to breathe," said Nawrot. "But what people can do is avoid busy roads as much as possible. There can be very high levels next to busy roads, but just a few meters away can be lower."
Professor Jonathan Grigg from Queen Mary University of London said of the research: "This is the beginning of showing that this is a 'plausible mechanism' that could be causing these effects (miscarriage)."
Despite widespread efforts to reduce air pollution, 90 percent of the world's population still lives in areas where levels exceed WHO guidelines.
Even low levels make a difference, and research has shown that particularly among city dwellers, particles are crossing over into vital organs, including the brain and heart.
Last year the director general of the WHO, Tedros Adhanom Ghebreyesus, said air pollution was becoming "the new tobacco".
"The world has turned the corner on tobacco. Now it must do the same for the 'new tobacco'– the toxic air that billions breathe every day," he said. "No one, rich or poor, can escape air pollution. It is a silent public health emergency."