China burns about half of the world ’s coal and emits heavy metals Such as mercury and lead, into the atmosphere And affect the growth and development of neighboring children. But what if you do n’t live in China or eat something made in China? You can also be exposed to mercury in the ocean If you eat fish and seafood, but some people drink Chinese tea.
China is one of the largest exporters, but its rapid industrialization Has caused concern about lead pollution. Lead is a poison that can affect almost every organ in the body.
And the more lead in the soil, the more it will eventually remain in the tea, The closer the tea is to the highway, the higher the lead level, Implies that lead-containing gas-was not banned in China until 2000- It may also play a role. Just like bigger, longer-lived fish accumulate more mercury, Leaves that live longer accumulate more lead. Young tea leaves have two to six times less lead than mature tea leaves.
So it ’s not just for making young leaves of green tea and white tea It has significantly less lead than the aged leaves used to make black tea and oolong tea, And the lead in black tea and oolong tea seems It is easier to get into tea water when brewing.
So the health risk of lead may be 100 times lower, Compare green tea with oolong tea and black tea. Since some fungicides may contain heavy metal impurities, Someone may assume that there will be less lead pollution in organic tea, But in the study of 30 common teas on the shelves of North American stores, Poisonous element pollution does not seem to be less than conventional tea, Although pesticide pollution of organic tea is much less.
Regarding lead, the source of tea is the country of origin, Seems to be the most important. So, bottom line, how much tea is safe to drink? According to the strictest security restrictions in the world- Parameters like Prop 65 in California- And the largest tea lead pollution study from around the world, This is what I can propose. If you are not pregnant and only drink green tea, It doesn’t matter where you get your tea, Drink as much as you want.
You can drink a cup of tea every day, or 15 cups a day, However, given the average level of lead in Chinese black tea samples, More than three cups per day will exceed the daily safety limit of lead, Or at least it may exceed it. If you drink tea, Throw away the tea leaves or tea bags.
If you are eating leaves, it ’s like drinking matcha, This is powdered green tea, or throw the tea leaves into your juice Like what I like to do, I will not add more than two or three teaspoons Unless you use Japanese green tea, it contains very low levels of lead You can safely eat 15 scoops a day.
The only reason I will warn more than eight spoons is that it may exceed The daily recommended limit for adult caffeine. What about children? If you are a 70-pound 10-year-old child, drinking green tea lead is not a problem, But children ’s safe caffeine intake Maybe about 3 mg per kg,
This will limit you to about four drinks a day, although I will not add More than two teaspoons of Japanese green tea into the child’s juice Because of caffeine, and more than a spoonful of Chinese green tea because of lead pollution.
Similarly, I do n’t want to see children drink more than one cup of black tea a day Not to let them eat leaves. What about pregnant women? Pregnant women should be able to drink a cup of green tea every day During pregnancy, no matter where the source is, according to the average tea lead content, And the limit of Japanese tea is only the limit of more than 4 cups of caffeine per day.
I do not recommend drinking black tea during pregnancy, Or eat any kind of tea unless you know Tea is obtained from low-lead sources.