A new study has revealed that the most convenient way to heat food could lead to ingesting large amounts of microplastics. From quickly reheating food to making mug cakes, microwaves have become an essential addition in the kitchen. Now, a new study has revealed that microwaving plastic baby food containers can release massive amounts of nanoplastics and could be hazardous to health.

Experiments by researchers at the University of Nebraska have shown that, in some cases, reheating plastic baby food containers can release more than 2 billion nanoplastics and 4 million microplastics for every square centimeter of container, according to a university news release.

The Nebraska research team further found that three-quarters of the cultured embryonic kidney cells had died after two days of exposure to the toxic particles released by the containers.

Kazi Albab Hussain, the study’s lead author, said it’s important to understand how much microplastics and nanoplastics people consume. “When we eat specific foods, we are usually informed or have an idea about their caloric content, sugar levels, and other nutrients. I think it is equally important that we are aware of the amount of plastic particles present in our food,” Hussain added in the statement.

The specific number of particles released when microwaving food depends on a large number of factors, including the type of plastic container and the food it contains. According to research, infants who drink microwaved water products and young children who consume microwaved dairy products ingest the highest relative concentrations of plastic. Notably, the study also showed that refrigeration and storage of food at room temperature for about six months could lead to the release of micro- and nanoplastics, according to the statement.

To better understand the effects of reheating baby food, the researchers collaborated with Svetlana Romanova of the University of Nebraska Medical Center to culture and expose embryonic kidney cells to actual plastic particles released from the containers, according to Hussain. After 72 hours, only 23% of kidney cells exposed to the highest concentrations survived.

In June, a study from the American Institute of Physics revealed that microplastics tend to accumulate in hot spots in the nasal cavity and oropharynx, or the back of the throat, and can pose serious health risks. In a 2022 report, the World Health Organization noted that information on exposure to air, drinking water, food, and beverages is limited and more research is required.