An alarming study published in the journal Environmental Science and Technology Letters found that infant feces contain some 10 times more microplastics in them compared to feces obtained from adults. That’s an average of 36 µg (micrograms; 1000 µg = 1 mg) of poly(ethylene terephthalate) (PET) per gram of baby poo. The authors even found traces of PET in infants’ first feces.
“Unfortunately, with the modern lifestyle, babies are exposed to so many different things for which we don’t know what kind of effect they can have later in their life,” says Kurunthachalam Kannan, study co-author and a New York University School of Medicine environmental health scientist.
The research team got these results by passing dirty diapers from six (6) one-year-olds through a filter, allowing them to collect these microplastics, or fragmented plastic pieces just a few millimeters in size at most. They compared their results to three samples of meconium, or a newborn’s first feces, and adult stool samples from 10 adults. To eliminate the chances of erroneous data, the scientists screened out the presence of polypropylene, another type of plastic which the feces samples might have picked up off diapers, leaving only traces of PET for analysis.
Here, they found ten times the amount of PET concentrations per gram of feces in infants compared to adults. They also found traces of polycarbonate, another type of plastic which is often used as a stand-in for glass like in eyeglasses. The meconium obtained also contained these plastics, meaning these microplastics were already present in the babies’ bodies before they even left their mother’s womb—corresponding with research published earlier this year in the journal Pharmaceutics which showed the presence of microplastics in human placenta and meconium in a clinical setting.
The heightened PET levels in infants are said to be associated with the sheer amounts of plastic implements surrounding babies today: PET as polyester fibers in clothing, plastic in formula and milk bottles, plastic toys, plastic food containers—even whatever plastic these babies might have accidentally chewed on. In fact, previous research has shown that hot formula can erode very tiny bits of plastic off babies’ drinking bottles, which this particular study seemingly confirms.
One particular class of otherwise foreign chemicals that the authors are also wary of are known as endocrine-disrupting chemicals (EDCs). Kannan believes that these EDCs “affect early life stages,” which to them is a “vulnerable period” of a child’s life.
These EDCs are associated with several side effects at high exposures, including adverse reproductive and neurological effects. In fact, the infamous bisphenol A (BPA), a chemical precursor to several common plastics and can thus remain in plastic products, is an EDC which has been linked to diseases like cancer.
Jodi Flaws, a reproductive toxicologist from the University of Illinois at Urbana-Champaign who’s unrelated to the study, believes that “[we] should be concerned because the EDCs in microplastics have been shown to be linked with several adverse outcomes in human and animal studies.” Flaws continued: “Some of the microplastics contain chemicals that can interfere with the normal function of the endocrine system.”
University of Strathclyde researcher Deonie Allen also expressed growing concerns about the findings of this paper. “This is a very interesting paper with some very worrying numbers. […] We need to look at everything a child is exposed to, not just their bottles and toys.” Similarly, Flaws expressed the need for further research in order to identify and isolate whatever other effects these microplastics have on our bodies, and whether or not some of them are a cause for immediate concern. “We need many more studies to confirm the doses and types of chemicals in microplastics that lead to adverse outcomes.”
It can prove challenging to completely eliminate the presence of plastics around babies, especially given their sheer ubiquity in modern life. Despite this, some ways of avoiding infants’ exposure to these microplastics can be as simple as not pouring hot liquid inside babies’ drinking bottles, and instead preparing their formula in another container before pouring them into the sippy cup once it’s cooled. These choices, along with other decisions like choosing more environmentally-friendly clothing for your child, can not only help in ecological preservation efforts, but also potentially spare your baby from future ailments.
(If you want to know more about the plastics that are around us, check out the Modern Sciences primer on what the numbers below most plastic products mean. For more scientific efforts on reducing plastic waste, read further on how scientists plan to make use of bacteria to convert waste PET into a usable chemical in the food industry.)
References
- Braun, T., Ehrlich, L., Henrich, W., Koeppel, S., Lomako, I., Schwabl, P., & Liebmann, B. (2021). Detection of microplastic in human placenta and meconium in a clinical setting. Pharmaceutics, 13(7), 921. https://doi.org/10.3390/pharmaceutics13070921
- Simon, M. (2021, September 22). Baby poop is loaded with microplastics. Wired. https://www.wired.com/story/baby-poop-is-loaded-with-microplastics/
- Zhang, J., Wang, L., Trasande, L., & Kannan, K. (2021). Occurrence of polyethylene terephthalate and polycarbonate microplastics in infant and adult feces. Environmental Science & Technology Letters. https://doi.org/10.1021/acs.estlett.1c00559
