Microplastics — tiny plastic pieces less than 5 mm in size — are everywhere, from indoor dust to food to bottled water. So it’s not surprising that scientists have detected these particles in the feces of people and pets. Now, in a small pilot study, researchers reporting in ACS’ Environmental Science & Technology Letters discovered that infants have higher amounts of one type of microplastic in their stool than adults. Health effects, if any, are uncertain.
Little is known about the magnitude of human exposure to microplastics or their health effects. Although microplastics were once thought to pass harmlessly through the gastrointestinal tract and exit the body, recent studies suggest 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. Kurunthachalam Kannan at the New York University School of Medicine and colleagues wanted to assess human exposure to two common microplastics — polyethylene terephthalate (PET) and polycarbonate (PC) — by measuring levels in infant and adult feces.
The researchers used mass spectrometry to determine the concentrations of PET and PC microplastics in six infant and 10 adult feces samples collected from New York state, as well as in three samples of meconium (a newborn infant’s first stool). All samples contained at least one type of microplastic. Although average levels of fecal PC microplastics were similar between adults and infants, infant stool contained, on average, more than 10 times higher PET concentrations than that of adults. Infants could be exposed to higher levels of microplastics through their extensive use of products such as bottles, teethers and toys, the researchers say. However, they note that larger studies are needed to corroborate these findings.
The authors acknowledge funding from the National Institute of Environmental Health Sciences, the NIH Office of the Director, the National Natural Science Foundation of China, the 111 Program of the Ministry of Education of the People’s Republic of China and the Chinese Scholarship Council.
The paper’s abstract will be available on September 22 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acs.estlett.1c00559