In utero: A 22-week-old foetus. (Photo By BSIP/UIG Via Getty Images)
For the first time, scientists have found microplastic particles in human placentas.
The Italian researchers behind the study found that microplastic — particles smaller than 5mm deriving from the degradation of plastic objects in the environment — were found in all placental portions: maternal, foetal and amniochorial membranes.
“Microplastics carry with them substances which act as endocrine disruptors could cause long-term effects on human health,” the researchers write in an article titled Plasticenta: First Evidence of Microplastics in Human Placenta, published in the January 2021 issue of the journal Environment International.
The researchers collected six human placentas from healthy, consenting women, who had normal pregnancies and births, to evaluate the presence of microplastics.
In total, 12 microplastic fragments were found in four placentas (five in the foetal side, four in the maternal side and three in the chorioamniotic membranes).
“All of them were pigmented. Three were identified as stained polypropylene. While for the other nine it was possible to identify only the pigments, which were all used for human-made coatings, paints, adhesives, plasters, finger paints, polymers and cosmetics and personal care products,” the authors write.
Because of the crucial role of the placenta in supporting foetus development and acting as an interface between foetus development and the external environment, the presence of potentially harmful plastic particles is a matter of great concern. The possible consequences on pregnancy outcomes and the foetus are the “transgenerational effects of plasticisers on metabolism and reproduction”, they warn.
Further studies need to assess whether the presence of microplastics in the human placenta may trigger immune responses or lead to the release of toxic contaminants, which could harm pregnancies.
The researchers describe how pigments in all analysed microplastics are explained by the wide use of those compounds to colour not only plastic products but also paints and coatings, which are as ubiquitous as microplastics.
One of the pigments detected is used in a wide variety of cosmetics and microplastics have been detected in food, in particular in seafood, sea salt and drinking water.
“Microplastics have also been detected in the gastrointestinal tract of marine animals and also human intestines,” write the authors.
“Inside tissues, microplastics are considered foreign bodies by the host organism, and as such, trigger local immune reactions. Furthermore, microplastics can act as carriers for other chemicals, such as environmental pollutants and plastic additives, which may be released and are known for their harmful effects.”