Testing the teas

To check their speculation, the authors bought Lipton and Infusions industrial tea luggage, in addition to a wide range of loose-leaf teas and natural alternate options: black tea, inexperienced tea, white peony tea, oolong tea, rooibos tea, and chamomile tea. The tea luggage had been of various sorts (cotton, cellulose, and nylon). They brewed the tea the identical manner each day tea drinkers do, steeping the tea for varied time intervals (mere seconds to 24 hours) in water spiked with elevated recognized ranges of lead, chromium, copper zinc, and cadmium. Tea leaves had been eliminated after steeping by pouring the tea via a cellulose filter right into a separate tube. The workforce then measured how a lot of the poisonous metals remained within the water and the way a lot the leaves had adsorbed.

It seems that the kind of tea bag issues. The workforce discovered that cellulose tea luggage work one of the best at adsorbing poisonous metals from the water whereas cotton and nylon tea luggage barely adsorbed any contaminants in any respect—and nylon luggage additionally launch contaminating microplastics in addition. Tea sort and the grind degree additionally performed a component in adsorbing poisonous metals, with finely floor black tea leaves performing one of the best on that rating. It’s because when these leaves are processed, they get wrinkled, which opens the pores, thereby including extra floor space. Grinding the tea additional will increase that floor space, with much more capability for binding poisonous metals.

However probably the most important issue was steeping time: the longer the steeping time, the extra poisonous metals had been adsorbed. Based mostly on their experiments, the authors estimate that brewing tea—utilizing a tea bag that steeps for 3 to 5 minutes in a mug—can take away about 15 % of lead from ingesting water, even water with concentrations as excessive as 10 elements per million.