Coffee lovers beware: that morning takeaway cup may be releasing thousands of microplastic particles into your drink. In Australia alone, we use a staggering 1.45 billion single-use hot beverage cups every year, along with roughly 890 million plastic lids. Globally, that number swells to an estimated 500 billion cups annually.
New research published in the Journal of Hazardous Materials: Plastics reveals that heat is a primary driver of microplastic release, and the material of your cup matters more than you might think.
What are microplastics? These are tiny plastic fragments ranging from about 1 micrometre to 5 millimetres in size. They can be created when larger plastic items break down or released directly from products during normal use. These particles end up in our environment, our food, and eventually, our bodies. While the long-term health effects of microplastics are still being studied, it’s essential to be aware of potential sources in our daily lives.
Temperature matters when it comes to microplastic release. A meta-analysis of 30 peer-reviewed studies showed that as the temperature of the liquid inside a container increases, the release of microplastics generally increases too. The rougher texture of all-plastic cups makes it easier for particles to break away when exposed to heat, leading to significant microplastic release.
To see how this works in the real world, researchers tested 400 coffee cups in Brisbane, including plastic cups made of polyethylene and plastic-lined paper cups. The results showed that paper cups with plastic linings released fewer microplastics than all-plastic cups, especially when exposed to hot liquids. Switching from cold to hot water increased microplastic release by about 33% in all-plastic cups.
To manage the risk of ingesting microplastics, consider using a reusable cup made of stainless steel, ceramic, or glass for hot drinks. If you must use a disposable cup, opt for plastic-lined paper cups as they generally shed fewer particles. Avoid putting boiling liquids directly into plastic-lined containers and ask baristas to make your coffee slightly cooler to reduce exposure to microplastics.
By understanding how heat and material choice interact, we can make better choices for our daily caffeine fix. It’s time to rethink our takeaway cup habits and prioritize our health and the environment.
