Delivery lessons Q&A
YOSSI, grade 6, boy.
Why is mercury harmful to the body?
Type of mercury.
There are many different types of mercury, as shown in the table below.
There are many more, but some of them are listed here.
Depending on the type of mercury, it may or may not be harmful to living organisms.
In this article, we would like to answer about methylmercury, the famous cause of Minamata disease.
Methylmercury
Have you ever seen methylmercury? The picture below shows real methylmercury.
Methylmercury and the brain
Have you heard that methylmercury can cause brain injury when taken into the body?
The brain has a barrier-like area called the blood brain barrier. It allows only what is needed in the brain to pass through and prevents what should not enter the brain from passing through. Methylmercury has to be stopped at the barrier too. But methylmercury can pass through the barrier and enter the brain, causing brain damage. Methylmercury taken in with food is absorbed through the gastrointestinal tract. In the gastrointestinal tract, it is absorbed mainly by binding to cysteine. As shown in the diagram below, methylmercury bound to cysteine is similar in structure to methionine, which is an essential amino acid for humans. Because the structure is similar to methionine, it can easily pass through the blood brain barrier, which is a barrier, and cause brain injury.