A new study sends a cautionary note to the millions of moms and dads who bottle-feed their babies.
The
study, published in the journal Nature Food, reveals that the world’s infants (up to 12 months old) swallow an average of 1.6 million microplastics every day from baby bottles containing
formula. In North America, the estimate for microplastic exposure was far higher: 2.28 million tiny particles per day.

What are microplastics?
Microplastics are pieces of plastic that are less than 5 millimeters long.
In the study, the microplastic particles originated from polypropylene, one of the most common plastics in the world for food preparation and storage. These plastic products include
bottles for feeding infants.
The researchers found extremely high levels of microplastics were released from infant feeding bottles during the heating of baby formula. The higher the heat, the more microplastics that were released — up to 16.2 million microplastics per liter of formula. They examined the effects of heat on 10 bottles that represent more than 80% of the global market for these bottles.
“When we saw these results in the lab, we recognized immediately the potential impact they might have. [But] the last thing we want is to unduly alarm parents, particularly when we don’t have sufficient information on the potential consequences of microplastics on infant health,”
says study co-author
John Boland, a chemistry professor at Ireland’s Trinity College Dublin.
Study co-author
Liwen Xiao, an engineering professor at Trinity College, notes that previous research about human exposure to microplastics has focused mostly on how these particles wind up in the food chain from degraded plastics in oceans and soil.
“Our study indicates that
daily use of plastic products is an important source of microplastic release, meaning that the routes of exposure are much closer to us than previously thought,” Xiao says. “We need to urgently assess the potential risks of microplastics to human health. Understanding their fate and transport through the body following ingestion is an important focus of future research. Determining the potential consequences of microplastics on our health is critical for the management of microplastic pollution.”
In an
article published by The Conversation, two Dublin College researchers involved in the study,
Dunzhu Li and
Yunhong Shi, note that previous research suggests children and adults in the U.S. are exposed to between 74,000 and 211,000 particles of microplastics over an entire year through the food they eat, the water they drink and the air they breathe. Those levels are dramatically below what was found in the study of feeding bottles for babies.
Ways to reduce microplastics exposure
Li and Shi outline four ways that parents can reduce the consumption of microplastics by babies who are fed formula in plastic bottles:
- Rinse sterilized feeding bottles with cool, sterile water.
- Always prepare formula in a non-plastic container.
- After the formula has cooled to room temperature, transfer it to the cooled, sterilized feeding bottle.
- Avoid rewarming prepared formula in plastic containers, especially with a microwave oven.
To avoid plastic baby bottles altogether, the
Mama Hippie website offers these four recommendations:
- Glass bottles. Keep in mind that these bottles may break under high heat.
- Stainless steel bottles.
- Bottles made of medical-grade silicon.
- Hybrid bottles made of at least two materials. For instance, a glass bottle could be cradled by a plastic shell.
In 2012, the U.S. Food and Drug Administration
banned baby bottles and sippy cups made from bisphenol-A (BPA), a toxic plastics chemical. But that happened only after lawmakers in several states had already prohibited the use of BPA in these containers and many consumers had already stopped purchasing BPA-laden baby bottles and sippy cups.
Underscoring the findings of the Trinity College study,
Dr. W. Kyle Mudd, a pediatrician affiliated with the Cleveland Clinic Children’s Hospital,
says that even a BPA-free plastic bottle carries some risk. Overall, though, Mudd advises parents not to panic about the presence of plastic in baby bottles.
“Parents should be aware of the potential risks of plastic, but there’s no reason to be overly anxious,” Mudd says. “There are always some risks in life. As parents, we just have to do our best to minimize them.”
He adds: “The nutrition your child gets throughout childhood is likely much more important than what kind of bottle you use.”
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