Toxic air pollution particles are found in pregnant women's PLACENTAS for the first time and scientists fear they could trigger premature deliveries or low birth weights
- Researchers from Belgium scanned biopsies of 28 women's placentas
- They found black carbon particles, which come from burning fossil fuels
- Evidence of carbon travelling into the foetus has not yet been discovered
Scientists have found evidence of soot from air pollution travelling through the placenta towards an unborn baby.
In an apparent world-first, researchers from Belgium discovered pieces of black carbon in the placentas of 28 women from polluted areas.
The placenta is the source of all a baby's oxygen and nutrients while they're in the womb and ties the mother and baby's health tightly together.
This evidence shows traffic and industrial fumes can make their way through the mother's body to her baby, the team said, and they warned it may cause birth complications or defects.
Another expert called the findings 'a concern' and said more research must be done to examine the effects of pollution on foetuses.
Scans of tissue in women's placentas revealed evidence of black carbon from air pollution, which scientists are afraid could contribute to premature births or low birth weights (Pictured: Black carbon particles can be seen glowing white and indicated by small white arrows on a scan of a woman's placenta tissue)
Researchers led by Hasselt University took flesh samples from each of the 28 women and scanned them in a lab.
They found all had evidence of black carbon, which they said most often comes from burning fossil fuels such as exhaust fumes from diesel engines.
The black carbon was found on what's described as the foetal side of the placenta – the part of the organ closest to the developing baby.
And the build-up was higher in women who lived in more polluted areas.
The 10 women who were exposed to the most black carbon themselves in turn had the most of it in their placentas – scans showed an average of 2.42 micrograms per metre cubed in that group.
But even the women in the least polluted areas still had detectable levels of carbon – an average of 0.63 micrograms per cubic metre.
Black carbon is a sooty material expelled by burning fossil fuels like diesel, petrol, wood and coal and makes up most air pollution.
It is known to be harmful to human tissues and polluted air has been linked to various types of cancer and is known to damage the heart, brain, lungs and fertility.
In pregnancy specifically, one expert said high blood pressure and even seizures have been linked to pollution in the air.
'Various studies have already described associations between prenatal ambient air pollution exposure and impaired birth outcomes,' Dr Tim Nawrot, from Hasselt University, and his colleagues wrote in the journal Nature Communications.
'For instance, combustion-related particulate matter, including black carbon, is associated with lower birth weight, preterm birth, and intrauterine growth restriction.
'Up to now, it remains unclear how exactly adverse effects are provoked in the foetus but various potential mechanisms have been proposed including both indirect (e.g., intrauterine inflammation) and/or direct (e.g., particle translocation) manners.'
In these scans of the placenta tissue of women living in highly-polluted areas, sooty black build-up of carbon can be seen in otherwise healthy cells
These scans show the glowing white tiny chunks of carbon pointed out by white arrows in the placenta tissue of two of the women in the study
Of the women in the study, five gave birth before they reached full-term and 23 gave birth in a healthy time frame.
The findings do not prove that pollution can make it the entire way into a foetus's body and Dr Nawrot's team said this has never been proven.
They do, however, appear to show the closest carbon has ever been seen to travel to the unborn baby.
And although the effects of pollution aren't well understood, the team said they had observed carbon damaging DNA in unborn children.
It can trigger a process called methylation, in which the action a gene tells the body to carry out can be changed by a chemical from outside being added to the DNA strand.
Methylation may cause mutations which cause tumours to grow and is linked to other conditions such as multiple sclerosis and diabetes.
King's College London's Professor Andrew Shennan, who was not involved with the study, said: 'Small particles, such as through smoking, can cause considerable disease related to the placenta, and these findings of particles in the placenta are a concern.
'Their possible effects on the baby and mother warrant further investigation. High blood pressure and fits in pregnancy have been linked to household pollution.'
The University of Auckland's Associate Professor Jennifer Salmond added: 'Children are particularly vulnerable to poor air quality during foetal development and in the first few years of life when exposure can result in life-long changes to development and permanent damage to lung tissue.
'Although previous studies have shown that it is possible for foetal development to be affected by poor air quality, this study is important because it is the first study to demonstrate that black carbon can cross into the placenta.'
WHAT HAVE RECENT STUDIES SHOWN POLLUTION CAN DO TO OUR HEALTH AND BODIES?
CAUSE CHILDREN TO HAVE A LOW IQ: Researchers at the University of California, San Francisco, found in May 2019 that children born to mothers who live in polluted areas have an IQ that is up to seven points lower than those living in places with cleaner air.
CAUSE CHILDREN TO HAVE POORER MEMORY: Researchers at the Barcelona Institute for Global Health found boys exposed to greater levels of PM2.5 in the womb performed worse on memory tests by the time they are 10.
DELAY THE DEVELOPMENT OF CHILDREN: Youngsters who live less than one-third of a mile away from busy roads are twice as likely to score lower on tests of communication skills in infancy, found researchers at Eunice Kennedy Shriver National Institute of Child Health in April. They were also more likely to have poorer hand-eye coordination.
MAKE CHILDREN MORE ANXIOUS: University of Cincinnati scientists claimed pollution may alter the structure of children's brains to make them more anxious. Their study of 14 youngsters found rates of anxiety was higher among those exposed to greater levels of pollution.
CUT YOUR CHILD'S LIFE SHORT: Children born today will lose nearly two years of their lives because of air pollution, according to a report by the US-based Health Effects Institute and the University of British Columbia in April 2019. UNICEF called for action on the back of the study.
RAISE A CHILD'S RISK OF AUTISM: Researchers at Monash University in Australia discovered youngsters living in highly polluted parts of Shanghai have a 86 per cent greater chance of developing ASD. Lead author Dr Yuming Guo said: 'The developing brains of young children are more vulnerable to toxic exposures in the environment.'
CAUSE ASTHMA IN CHILDREN: Four million children around the world develop asthma each year because of road traffic pollution, a major study by academics at George Washington University estimated. Experts are divided as to what causes asthma - but exposure to pollution in childhood increases the risk by damaging the lungs.
MAKE CHILDREN FAT: University of Southern California experts found last November that 10 year olds who lived in polluted areas when they were babies are, on average, 2.2lbs (1kg), heavier than those who grew up around cleaner air. Nitrogen dioxide pollution could disrupt how well children burn fat, the scientists said.
LEAVE WOMEN INFERTILE EARLIER: Scientists at the University of Modena, Italy, claimed in May 2019 that they believe pollution speeds up ageing in women, just like smoking, meaning they run out of eggs faster. This was based on them finding almost two-thirds of women who have a low 'reserve' of eggs regularly inhaled toxic air.
RAISE THE RISK OF A MISCARRIAGE: University of Utah scientists found in January that pregnant women are 16 per cent more likely to suffer the heartbreak of a miscarriage if they live in areas of high pollution.
RAISE THE RISK OF BREAST CANCER: Scientists at the University of Stirling found six women working at the same bridge next to a busy road in the US got breast cancer within three years of each other. There was a one in 10,000 chance the cases were a coincidence, the study said. It suggested chemicals in the traffic fumes caused the cancer by shutting down the BRCA genes, which try to stop tumours growing.
DAMAGE A MAN'S SPERM: Brazilian scientists at the University of Sao Paulo found in March that mice exposed to toxic air had lower counts and worse quality sperm compared to those who had inhaled clean air since birth.
MAKE MEN LESS LIKELY TO GET SEXUALLY AROUSED: Scientists at Guangzhou Medical University in China found rats exposed to air pollution struggled to get sexually aroused. Scientists believe it may also affect men, as inhaling poisonous particles may trigger inflammation in blood vessels and starve the genitals of oxygen – affecting men's ability to become sexually aroused.
MAKE MEN MORE LIKELY TO HAVE ERECTILE DYSFUNCTION: Men who live on main roads are more likely to have difficulty getting an erection due to exposure to pollution, a Guangzhou University in China study suggested in February. Toxic fumes reduced blood flow to the genitals, tests on rats showed, putting them at risk of developing erectile dysfunction.
RAISE THE RISK OF PSYCHOSIS: In March, King's College London scientists linked toxic air to intense paranoia and hearing voices in young people for the first time. They said uncovering exactly how pollution may lead to psychosis should be an 'urgent health priority'.
MAKE YOU DEPRESSED: Massachusetts Institute of Technology researchers found in January that that the more polluted the air, the sadder we are. Their study was based on analysing social media users in China alongside the average daily PM2.5 concentration and weather data where they lived.
CAUSE DEMENTIA: Air pollution could be responsible for 60,000 cases of dementia in the UK, researchers from King's College London and St George's, University of London, calculated last September. Tiny pollutants breathed deep into the lungs and enter the blood stream, where they may travel into the brain and cause inflammation – a problem which may trigger dementia.