Warming and shaking milk in plastic baby bottles releases 16 million microplastic particles into every liter of milk
A new study reveals the horrifying fact that babies who drink milk or formula from heated plastic bottles are consuming millions of tiny pieces of plastic every day.
The amount of plastic babies consume from heated bottles dwarfs the amount humans consume from any other known source.
Previous research has estimated adults consume between 39,000 and 52,000 micro-plastic particles per year. The new study, published last week in Nature Food, finds babies fed with plastic bottles are ingesting as many as 4 million micro-plastic particles per day.
In the process of warming and shaking your baby’s bottle, you release millions of microplastic particles (fragments less than 5 millimeters long) and perhaps trillions of nanoplastic particles (each on the scale of billionths of a meter), the study found.
Researchers from Trinity College Dublin tested 10 brands of polypropylene baby bottles, representing two-thirds of the global market baby bottle market, and found they released between 1 million and 16 million particles per liter of fluid when heated.
Manufacturers shifted to using polypropylene in baby bottles about 10 years ago because of mounting evidence that BPA in polycarbonate baby bottles caused developmental problems in children.
The scientists followed the World Health Organization’s protocol for “the safe preparation of baby formula,” which includes sterilizing bottle in boiling water, drying, cooling, filling with 158-degree water, adding powder, shaking and cooling.
The higher the temperature, the more particles were released, the team found.
Water heated to room temperature, 77 degrees, and shaken caused the bottle to shed 600,000 particles per liter, indicating agitation alone caused plastic shedding.
At 158 degrees, 16.2 million particles per liter were released.
At 203 degrees, 55 million particles per liter were shaken loose from the bottle.
“The sterilization process itself exacerbates the level of microplastic formation, such that, if you leave out the sterilization step, even though it’s unsafe, you’ll reduce the number of microplastics that are actually generated,” Trinity College Dublin Materials Engineer John Boland tells Wired Magazine.
His team tested the bottles repeatedly for three weeks and found that they kept releasing particles over time. “What we think is happening is that as you use a bottle, you slowly start abrading the polymer,” he said.
While Boland recommends preparing formula in a non-plastic container and letting it cool before transferring it to a plastic bottle to lessen the toxic load, we wonder why anyone would use anything other than glass or their breast at this point?
Boland says the study has taught us we should “never, ever, ever use a microwave oven to heat anything with a plastic container … Because what happens is the local heating of the plastic and the water together gives enhanced levels of microplastic generation. And so that combination we think is particularly potent.”