10 Oct 2019

Can air pollution pass into the placenta of a pregnant woman?

It was widely reported in September 2019 that air pollution particles can pass from the lungs, via the bloodstream and into the placenta of pregnant women.


It’s hard to believe that air pollution can reach the unborn child, but this study raises the real possibility that particles could also be passed from mother to unborn child. Researchers have been working on this worrying possibility for some time now, and the latest evidence is stark.


Research at Queen Mary University of London

The study found that air pollution can travel from the lungs of pregnant mothers and make its way into the placenta. Researchers discovered this by examining the placentas of five non-smoking women using an optical microscope. They found 72 dark particles that appeared unusual among thousands of other healthy cells.


The shape of the particles was further examined under an electron microscope and they appeared to be the look the same as soot which is usually trapped in the macrophages of lungs, these large blood cells are a key part of the immune system and usually catch most of the bacteria and parasites in the lungs by effectively “eating” them.


In an article published by the Guardian* Dr Norrice Liu states, “particles do not need to get into the baby’s body to have an adverse effect, because if they have an effect on the placenta, this will have a direct impact on the foetus”.


A further study in Belgium found similar results where the placentas of 28 women were analysed with white light lasers, then analysed to calculate the number of carbon particles in the placenta. The NHS reported this story in the ‘Behind the news’ section of their website, validating growing concerns in the medical and scientific community about the effects of pollution on the unborn child.


How strong is the science?

Whilst further analysis is needed, the findings of these studies are being taken seriously by the wider health community. Unicef director Anthony Lake recently warned of the danger of air pollution to babies, “Not only do pollutants harm babies’ developing lungs, they can permanently damage their developing brains – and, thus, their futures.”


The NHS recently cautioned that some reports “overplayed what we know about the links between air pollution and poor outcomes in pregnancy”.


Guardian report September 2019


NHS Pregnancy and child September 2019


Belgian Study published September 2019