Air pollution particles have been detected on the foetal side of placentas by a study, indicating that unborn babies are regrettably exposed to the black carbon produced by motor traffic and fuel burning. The research is the first ever to demonstrate that the placental barrier can be penetrated by particles breathed in by the expecting mother. Researchers found thousands of the tiny particles per cubic millimeter of tissue in every placenta they analyzed.
The connection between exposure to polluted air and increased miscarriages, premature births and low birth weights is already well established. This research submits that the particles themselves may be the cause, not just the inflammatory effect bad pollution produces in mothers. Damage to foetuses can have lifelong consequences.
Prof Tim Nawrot at Hasselt University in Belgium, who led the study, said, “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.”
He added that governments have the responsibility of cutting air pollution but people should also avoid busy roads when possible.
A comprehensive global review determined that air pollution may be damaging every organ and practically every cell in the human body. Nanoparticles have also been found drifting across the blood-brain barrier and also detected in the hearts of billions of young city dwellers.
While air pollution is somewhat curbed in some nations, the evidence of damage caused by even low levels is rapidly increasing and 90% of the world’s population reside in places where air pollution is way above World Health Organization (WHO) guidelines.
This eye-opening research was published in the journal Nature Communications after examining 25 placentas from non-smoking women in the town of Hasselt which has particle pollution levels well below the EU limit but above the WHO limit. Researchers employed a laser technique to detect the black carbon particles as they have a unique light fingerprint.
In each and every case, they found nanoparticles on the foetal side of the placenta and the number allied with air pollution levels experienced by the mothers. On average, there were 20,000 nanoparticles per cubic millimeter in the placentas of mothers who lived adjacent to main roads. For those residing further away, the average was 10,000 per cubic millimeter.
The researchers also examined placentas from miscarriages and detected the particles in even in 12-week-old foetuses. Their first report suggesting possible pollution particles in placentas was presented at a conference in September 2018, though the actual composition had not been confirmed at that time.
Nawrot said that the detection of these particles on the foetal side of the placental barrier means it was very likely the foetuses were exposed. An effort to analyze foetal blood for particles is presently underway along with research to see if the particles cause DNA damage.
The team also observed black carbon particles in the urine of primary school children. This study was published in 2017 and revealed that an average of 10 million particles per milliliter in hundreds of nine-to-12-year-olds tested.
Nawrot explained, “It shows there is translocation of particles from the lungs to all organ systems. It is really difficult to give people practical advice because everyone has to breathe. 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.”
Prof Jonathan Grigg, whose group presented the first report of pollution particles in five placentas in September, appreciated the research and said the group’s work had since been expanded and would be published soon.
Grigg at the Queen Mary University of London in the UK said, “We see evidence of particles in all women – it is not like it is a one-off. It implies that every day we have these very small particles moving around our bodies. We should be protecting foetuses and this is another reminder that we need to get [air pollution] levels down. But people shouldn’t be totally scared.” He said the total weight of the tiny particles was small and more research was needed to determine their impact, but he advised people to use lower pollution transport options or public transport, rather than cars.
Grigg concluded, “This new field of research certainly focuses our attention on the direct role of particles getting to the tissues, rather than particles getting into the lungs and releasing other [inflammatory] substances.”
Research on air pollution now confirms full-scale bodily harm, from heart and lung disease to diabetes and reduced intelligence to brittle bones and damaged the skin. The WHO has called air pollution a “public health emergency” with recent analysis indicating 8.8 million early deaths each year. Unfortunately, scientists suspect even this may be “the tip of the iceberg”.