Drinking hot coffee from paper cups
Tens of thousands of microplastics released after 15 minutes of high-temperature exposure
Concerns are mounting that the everyday habit of drinking hot coffee or tea from paper cups may lead to exposure to microplastics and nanoplastics. Contrary to the common perception that paper cups are relatively safer than plastic cups, experts point out that high-temperature beverages can damage the inner coating layer of the cup, allowing microplastics to leach into the drink.
According to a study published by a research team at the Indian Institute of Technology (IIT) in the international environmental journal Journal of Hazardous Materials, when hot liquid at 85-90 degrees Celsius was poured into a paper cup and left for 15 minutes, the thin polyethylene (PE) film coating the inside of the cup was degraded by heat and released microplastics.
The experiment found that an average of about 25,000 microplastic particles were detected per 100 ml of beverage. It was also analyzed that approximately 10.2 billion plastic particles at the nano scale, which are difficult to see with the naked eye, were mixed into the drink. This means that even a single cup of hot instant coffee can lead to the intake of a substantial amount of microplastics and nanoplastics.
Looks like paper, but the inside is plastic-coated
To prevent liquid from seeping through, paper cups are lined with an internal plastic coating layer. Although they appear to be made entirely of paper, the researchers explained that this coating layer is relatively easily damaged when exposed to high-temperature liquids. In this process, not only microplastics but also certain chemical substances such as ionic components, fluorine, sulfates, and some heavy metals were detected together.
Because the released microplastics and nanoplastics are extremely small in size, there is a high likelihood that they can be absorbed into the body. Some particles may travel through the bloodstream and reach deep into internal organs, and over the long term, they are suspected of potentially disrupting the immune system or causing hormonal imbalances.
For hot drinks, reusable cups such as stainless steel or glass are recommended
The British outlet The Independent also recently reported that takeaway coffee cups, including paper cups, can be a source of microplastic exposure. According to the report, tests conducted on 400 disposable cups collected in the Brisbane area of Australia showed that, although plastic-coated paper cups released fewer particles than cups made entirely of plastic, microplastics were detected in both types of cups.
Given that hundreds of billions of disposable coffee cups are used worldwide every year, experts say it is difficult to consider paper cups completely free from the risk of microplastic exposure. They argue that the very perception of paper cups as a safe alternative to plastic cups is misguided.
Experts advise that the best option when drinking hot beverages is to use reusable cups made of stainless steel, glass, or ceramic. They add that if one has no other choice but to use a disposable cup, exposure can be reduced by either drinking the beverage within as short a time as possible, or by allowing boiling-hot drinks to cool slightly before pouring them into the cup, thereby lessening the physical stress exerted on the plastic coating layer.
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