In recent years, plenty of research has shown that a daily tea habit can have some steep health benefits. But if you dunk tea bags in steamy water, you may be drinking microplastics with your brew, say researchers at Quebec’s McGill University. They found that steeping tea bags made with plastic (yes, surprise, many bags are made from plastics like polyethylene terephthalate) at a brewing temperature of 203 degrees Fahrenheit released 11.6 billion microplastics and 3.1 billion nanoplastics into a single cup of tea.

This comes on the heels of other research showing that plastic is increasingly finding its way into the food chain in everything from beer to seafood. We still don’t know if there are any health concerns associated with the amount of microplastics—pieces measuring less than 5 millimeters in any dimension—you would take in from a cup or more of tea each day. However, you can lower your exposure by purchasing your tea from brands that make their bags only from paper or by being extra-cautious and choosing loose-leaf options, which serve the dual purpose of creating less waste.