Study warns of the dangers of drinking coffee from plastic cups

According to the study, published in the Journal of Hazardous Materials: Plastics, heat is the main factor in stimulating the emission of microplastics, while the type of cup material plays a crucial role in the amount of particles emitted.

The researchers explained that microplastics are fragments ranging in size from 1 micrometer to 5 millimeters, and can transfer to the environment, food, and then to the human body, although there is no conclusive evidence yet about the extent of their accumulation or their long-term health effects.

Research results

The research team conducted an analysis that included data from 30 previous studies, which showed that higher liquid temperatures lead to a significant increase in the emission of plastic particles, with quantities ranging from hundreds of particles to more than 8 million particles per liter, depending on the type of material used.

The researchers also tested 400 cups of coffee in the Australian city of Brisbane, including both fully plastic cups and paper cups lined with plastic, at two temperatures representing iced and hot coffee.

The results showed that paper cups lined with plastic released fewer particles than pure plastic cups, while hot drinks led to an increase in emissions of about 33 percent in plastic cups.

Researchers estimated that a person who drinks 300 milliliters of coffee a day from a polyethylene plastic cup could ingest more than 360,000 microplastic particles annually.

Microscopic analysis indicated that the inner surfaces of the plastic cups are rougher, which facilitates the separation of particles, while heat accelerates this process by softening, expanding, and shrinking the plastic.

The researchers advised using reusable cups made of glass, ceramic , or stainless steel , and minimizing the pouring of extremely hot liquids directly into plastic-lined cups, to reduce potential exposure to microplastics.