By Dennis Thompson
High levels of microplastic particles are released from baby bottles during formula preparation, researchers discovered during lab testing.
Infants are likely exposed to an average daily dose of nearly 1.6 million microplastic particles through baby formula they drink from heated plastic bottles, researchers estimated in the Oct. 19 issue of Nature.
It’s not clear whether these particles represent either an immediate or long-term health risk to growing babies, however.
“How the microplastics would affect the infants’ health is still an unknown. There is still no data available,” said study researcher Liwen Xiao, an assistant professor of civil, structural and environmental engineering at Trinity College Dublin in Ireland.
Plastics shed particles as they wear down. Evidence is growing that humans regularly consume large amounts of micro- and nanoplastic particles, either via the food chain or through the direct release of particles from plastic packaging or storage materials into our food, the researchers said in background notes.
Microplastic particles are 5 millimeters or smaller, no bigger than a sesame seed. Nanoplastic particles are even tinier, with a diameter of 1 micron — a human hair has a diameter of about 50 microns.
Earlier this year, a study found microscopic plastic particles in all the major filtering organs of the human body. Plastic had contaminated tissue samples taken from the lungs, liver, spleen and kidneys of donated human cadavers, according to findings presented at the American Chemical Society’s annual meeting.
This research team tested 10 baby bottles that account for nearly 7 out of 10 bottles used around the world to feed infants, and found that heat was closely tied to the release of particles.
Bottles made of polypropylene plastic released up to 16.2 million microplastic particles per liter of liquid when sterilized and then exposed to warm 158-degree Fahrenheit water, researchers reported.
Warmer water at 203 degrees Fahrenheit caused an even greater release of microplastic particles, as much as 55 million particles per liter.