evidence: But research out this week in Environmental Science & Technology reveals that plastic tea bags are doing a lot more than holding on to your tea. When you steep them in hot water — AKA make tea — they break down just enough to release billions of plastic microparticles right into your beverage. [...] The new study, conducted by researchers at McGill University in Montreal, found a single plastic-based tea bag releases approximately, 11.6 billion microplastic particles and 3.1 billion nanoplastics (even smaller particles) into your mug. [...] To further complicate matters, tea can contain small amounts of metals and metalloids like aluminum, lead and chromium. And micro- and nano-plastics are known to be able to absorb things like heavy metals. When the researchers looked to their microplastic "tea" steeped from the bags, they indeed found that metals from the tea had glommed on to the microplastics from the bags.