Does tea contain lead? If so, why?

Tea is a special item that contains high lead, and there are several aspects of lead in tea, such as high lead content in tea garden soil, lead in old processing machinery alloys, lead in fertilizers, and lead pollution from automobile exhaust tea trees. In addition, some unscrupulous businessmen add a large amount of lead and chromium green to the tea in order to increase the light and color of the tea, which will make the lead content in the normal tea exceed the standard.

However, the water solubility of lead is not high, as long as it is within the specified level, there is no harm to the human body. The national health standard stipulates that the lead content in tea should be 2 mg kg. It can be drunk with confidence within this range.

How to drink tea safer? Experts have confirmed through experiments that the dissolution of lead in neutral water is very low, but the dissolution in acidic or alkaline liquids has increased, so the tea should be made of qualified tap water, of course, the selection of qualified natural water immersion tea, with a porcelain pot or purple clay pot is better than with a metal pot to make tea.

In addition, the Ministry of Agriculture's tea quality inspection must have carried out such a test a few days ago: the Shanghai Municipal Bureau of Technical Supervision sent to the sampling of the highest lead content of 4 kinds of Longjing tea, imitation tea, with 100 degrees Celsius boiling water for 1 hour, after measuring the lead content in the tea soup, the results of the four kinds of tea soup did not detect lead. It can be seen that although the lead content in tea is high, these lead is not soluble in tea soup or the leaching rate is very small, so it can be considered that it will not be ingested by the human body.

Leaded! However, different types of lead contain different amounts.

When I was in school, I did an experiment of atomic emission spectroscopy to measure the content of lead in tea, and measured the content of trace elements in the tea after brewing tea by making tea. Different teas also have different lead content, and oolong tea has more than ten times more lead than green tea! So, try to drink oolong tea sparingly.

Tea leaves. I don't know about the aluminum content test. This should be detected, and testing should be beneficial. Check it out on the web, OK.

How much lead is in tea, and what is the effect on the human body? There are different interpretations of this issue, and the actual results are also different. Some sources report that the lead in the tea leaves is very small or will not be leached into the tea soup, but there are also some reports that there will be 5 to 30% leaching.

However, the amount measured in tea soup is generally less than 10 micrograms. Suppose that according to 5 milligrams of tea (exceeding the standard multiple), such as 5 grams of tea leaves in 150 ml of water (higher than the conventional dosage), the leaching rate of lead in the tea soup is calculated as 30%, then 150 ml of tea soup contains only 5 micrograms of lead. The standard for lead in drinking water is 50 micrograms, which is 10 times higher

The World Health Organization and Japan set a standard of 100 micrograms, which is 20 times higher. Therefore, even according to the above extreme assumptions, it is safe for drinkers. Just because there is lead in tea, we can't take it for granted that it will enter the human body through drinking tea, and we can't associate lead with "poisoning" and "senile dementia".

Propaganda reports should be scientific, not far-fetched, let alone taken for granted. Lu Chengyin, deputy director of the Tea Quality Inspection Center of the Ministry of Agriculture, said that they recently conducted a test to determine the lead content in the tea soup after brewing the four kinds of Longjing tea with the highest lead content in the sampling for 1 hour with 100 degrees of boiling water, and the results showed that no lead was detected in the four kinds of tea soup. It can be seen that although the lead content in tea is high, these lead is not dissolved in tea soup or the leaching rate is very small, so everyone can drink tea with confidence.

Lead is a heavy metal, and if the human body consumes a large amount, it will definitely be poisoned. But I don't think it's a big problem with tea water.

What I said upstairs makes sense, drink it with confidence, and you won't get sick if you don't eat it cleanly.

It's a kind of poisoning.

1. Tea garden factors: air pollution, water pollution, soil pollution, fertilizer and pesticide pollution, as long as the tea tree contains lead in the process of growth, it will naturally be absorbed by the tea tree;

2. Tea tree factors: some tea trees are lead-loving, that is, they may absorb lead in the body, which is more absorbed than ordinary tea trees;

3. Picking process: caused by mechanical picking;

4. Processing process: During processing, the lead in the machinery pollutes the tea; In addition, a small number of unscrupulous tea merchants may add lead-containing additives, such as dyeing, flavor enhancers, etc., in order to look better in quality;

5. Packaging: Improper packaging, the packaging will also cause the lead content of tea to exceed the standard;

Lead is a toxic heavy metal. Therefore, lead and its compounds will cause harm to many systems such as nervous, hematopoietic, digestive, kidney, cardiovascular and endocrine after entering the body, and if the content is too high, it will cause lead poisoning.

In addition, if the domestic agency detects it, it will make the tea enterprises rectify and stop all work, which is extremely harmful.