select search filters
roundups & rapid reactions
before the headlines
Fiona fox's blog

expert reaction to study looking at placentas and particles which may be from air pollution

A study, published in Science of The Total Environment, looked at placentas and particles which may be from air pollution.


Prof Andrew Shennan, Professor of Obstetrics, King’s College London, said:

“Carbon particles have previously been detected in the placenta of pregnant women and these findings confirm this.  This is a technically impressive study that defines quantity and other details, as particles were found in 1% of cells.  Other substances such as metals were identified – like the carbon particles, these may be related to air pollution but this study can’t confirm that.

“However it remains uncertain if these findings cause harm to the baby.  There is no direct evidence of harm to the baby after many years of pregnant women exposed to air pollution, but other research has linked air pollution to early birth.  This is an important area to continue study, and this is valuable data.”


Prof Marian Knight, Professor of Maternal and Child Population Health, Nuffield Department of Population Health, University of Oxford, said:

“This small study showed microscopic evidence of particulate matter in the placenta; the source of these particles is unknown but is hypothesised to be from inhaled pollution.  Importantly, and reassuringly for other pregnant women, all women whose placentas were examined for the purposes of the study gave birth to healthy babies at term and had no complications.  All women lived in areas where there were higher than recommended levels of pollution but none of the women had their actual levels of exposure to pollution measured, and no placentas from women who did not live in high pollution areas were examined.  The significance of these findings is therefore unclear.”



‘Evidence for the presence of air pollution nanoparticles in placental tissue cells’ by Norrice M. Liu et al. was published in Science of the Total Environment.

DOI: 10.1016/j.scitotenv.2020.142235


Declared interests

Prof Andrew Shennan: “I have no conflicts in this subject matter.”

Prof Marian Knight: “None to declare.”

in this section

filter RoundUps by year

search by tag