KEY POINTS

  • Researchers tested infant and adult feces for the presence of microplastics
  • Infant feces had 10 times higher levels of microplastic PET compared to adult feces
  • Health effects linked to the findings remain "uncertain"

Humans are being exposed to microplastics often without their knowledge and it turns out even babies are not spared. They may even be more exposed to microplastics than adults, a study has found.

Microplastics (MP) are small pieces of plastics that are less than five millimeters long or about the size of a sesame seed, the National Oceanic and Atmospheric Administration (NOAA) noted. They could come from various sources such as larger pieces of plastic that degrade into smaller pieces or perhaps from the microbeads that can be found in products like toothpaste and beauty products.

Human exposure to microplastics and its possible health effects is a "global concern," the researchers of a new study, published Wednesday in Environmental Science and Technology Letters, noted. In 2020, for instance, researchers found that babies who are bottle-fed actually ingest over a million microplastic pieces each day.

In the small pilot study, the researchers sought to determine the concentrations of polyethylene terephthalate (PET) and polycarbonate (PC) microplastics in the feces samples of six infants and 10 adults from New York State, as well as in three samples of meconium or a newborn's first stool. PET and PC are two common microplastics, the American Chemical Society (ACS) noted in a news release and the researchers used mass spectrometry to examine the samples.

Interestingly, all of the samples had "at least one type of microplastic," the ACS said. And while the researchers found that the fecal PC microplastics in the adults' and infants' feces were rather similar on average levels, the PET concentrations in the babies' stool were actually 10 times higher on average compared to the adult stools. PET and PC microplastics were also found in "some" meconium samples.

"The estimated mean daily exposures from the diet of infants to PET and PC MPs were 83,000 and 860 ng/kg body weight per day, respectively, which were significantly higher than those of adults (PET: 5800 ng/kg-bw/day; PC: 200 ng/kg-bw/d)," the researchers wrote. "Our study suggests that infants are exposed to higher levels of MPs than adults."

This could be from the "extensive use" of items like bottles, toys and teethers, the researchers said as per ACS. However, more and larger studies are needed "to corroborate these findings."

So far, not a lot is known about microplastics and their full impact the NOAA said, calling it an "emerging field of study." The same also goes for its possible health impacts, as the ACS noted that "little is known" about the magnitude at which people are exposed to them as well as their possible health effects.

Previously, microplastics were thought to simply pass through the gastrointestinal tract "harmlessly," the ACS said. However, there has been evidence suggesting that the "tiniest pieces can cross cell membranes and enter the circulation."

"In cells and laboratory animals, microplastic exposure can cause cell death, inflammation and metabolic disorders," ACS noted.

As for the current study, the ACS said that health effects related to the findings, "if any, are uncertain."

baby-1866623_640 (3) representational image Photo: pixabay