Are there DBPs in that cup of tea? (Chlorine from tap water reacts with tea)

Science Daily / American Chemical Society / Environmental Science & Technology ^ | Sept. 15, 2021 | Jiafu Li, Md. Tareq Aziz, Caroline O. Granger, Susan D. Richardson.

[ConservativeMind]

Surpassed only by water, tea is the second most consumed beverage worldwide. When boiled tap water is used to brew tea, residual chlorine in the water can react with tea compounds to form disinfection byproducts (DBPs). Researchers measured 60 DBPs in three types of tea, unexpectedly finding lower levels in brewed tea than in tap water. However, they also detected many unknown DBPs with uncertain health effects.

Although disinfection is important to ensure drinking water safety, a downside is DBP formation. Tea contains about 500 compounds, including polyphenols, amino acids, caffeine and others, that can react with chlorine to form DBPs, some of which have been linked in epidemiological studies with cancer and adverse birth outcomes. In addition, DBPs can form from reactions with compounds in the tap water itself. Susan Richardson and colleagues wanted to conduct a comprehensive survey to measure 60 known DBPs in three green and black teas popular in the U.S.

The researchers brewed the teas and then measured the compounds using gas chromatography-mass spectrometry. Levels of the 60 DBPs were higher in tap water than in the brewed teas, likely because many compounds evaporated or were absorbed by tea leaves. However, the 60 known DBPs comprised only 4% of the total organic halogen in tea, indicating that the majority of these compounds in tea are uncharacterized. The team identified 15 of these compounds -- which likely form from the reaction of chlorine with natural phenolic and polyphenolic precursors in tea leaves -- for the first time in the beverage. Although no "safe" levels have yet been established for most DBPs, for the ones that are regulated, an average person would need to drink 18-55 cups of tea per day to exceed the limits established by the U.S. Environmental Protection Agency, the researchers say.

[grame]

I use Ahmad. Earl Grey is my go to, but English Breakfast, lemon green tea, and many of their flavored teas are great. They now have a place to order direct located in the US.

[jcon40]

Thanks for the post. I drink a quality Japanese green tea and filter the chlorine using activated charcoal filter plus change the filter per mfg recommendations. Seems to work

The sun helps reduce chlorine residual. Do you know if this works for sun tea or if you have to leave the lid off?

Also for years I owned a commercial dechlorinator used to neutralize the chlorine used for disinfection of newly installed water lines. It ran off of citric acid. I’ve heard vitamin C is also used to smaller scale.

I’m no expert but hadn’t seen these methods mentioned here.

I always thought a little chlorine might be good to flush the digestive system...Ha,ha. about equal to eating a handful of dirt, crept you never know what’s in the dirt unless you’ve tested it too.

And then there’s distilled water for drinking which brings out many opinions

[ConservativeMind]

It has to be removed before brewing, but the brewing involved did require heat, of which suntea uses less.

[jcon40]

I’ve heard powdered water is even more deadly

[Georgia Girl 2]

My sister used to live on Fleming Island. I was in Orange Park.

[redinIllinois]

Great thread!!

Thanks for posting