There’s mountains of evidence that people are eating plastic—a credit card’s worth per week, according to one study. I assumed this was something that affected only full-grown humans, but a new study shows that may not be the case. Infants are also at risk of consuming a massive amount of microplastic.
Research published in Nature Food on Monday suggests that heating up babies’ bottles to prepare their nursing formula releases tons of microplastic particles, which said babies are then slurping up. Since there’s evidence that microplastic consumption can expose humans to chemicals that disrupt hormone activities and may even be linked to increased risk of cancer, diabetes, and heart problems, this is pretty scary news.
The authors prepared baby formula in 10 different types of feeding bottles—which represented nearly 70% of all bottles that can be bought online around the world—under preparation guidelines set by the World Health Organization. All or part of each type of bottle was made of a common plastic called polypropylene.
After heating up the baby formula, the researchers tested the microplastic content of the formula in each vessel. They found that the bottles each contained a minimum of 1.3 million plastic particles per liter of formula, and that the worst offenders included up to 16.2 million particles per liter.
From this, they concluded that on average, an infant consumes nearly 1.6 million particles of microplastic per day. That’s about 2,600 times the amount that the average adult consumes from water, food, and air on a daily basis, which a 2019 study found was 600 particles a day.
The amount of polypropylene in a baby bottle made a big difference in how much microplastic it release when heated. Bottles completely made of the plastic produced more than the ones where the lid was made of plastic but the body was made of glass, for instance. But crucially, the researchers also found that the kind of bottle used was not the only factor that determined microplastic levels in formula. Some methods of preparing the baby formula also released more microplastic than others.
For instance, WHO recommends sterilizing baby bottles with scalding hot water periodically to eliminate bacteria. But doing so, the scientists found, increased the level of microplastic in bottle’s formula after the fact, because hot liquid releases more plastic from the bottle than cold. Similarly, the researchers found that using plastic kettles to heat water for the sterilization process resulted in a higher plastic particle content than when they used plastic-free kettles to heat the water.
The researchers also found that reheating formula in plastic containers upped its the plastic particle levels, especially when it was reheated using a microwave. Shaking the formula in the bottle also dislodges more plastic particles, resulting in more of them ending up in the formula.
Some of this may seem obvious, but the authors note that methods of formula preparation that release more microplastic are common. For instance, the study cites the Centers for Disease Control fundings that 35% of parents “occasionally” use microwaves to get powdered formula ready while 20% use the method frequently.
Much more research is needed to determine whether or not all of this microplastic consumption poses health risks for babies. But to be safe, the researchers call on global policymakers to take another look at the WHO formula preparation guidelines. It might also be a good idea to implement some standards for how much plastic baby bottles can contain.
It’s not like we need another reason to phase out plastic use. The world already has a huge plastic pollution crisis on its hands that could grow worse. The material is also made of petrochemicals, and the process used to create it releases dangerous, planet-heating pollutants, which poses a whole other risk for babies born today.