Blowfish is known as a poisonous fish. Let us clarify the properties and strength of the poison. Blowfish poison is tetrodotoxin with a molecular formula of C11H17N3O8. The tasteless, odorless and colorless poison paralyzes peripheral nerves and does not decompose even when heated up to 300 degrees. Accordingly, normal cooking does not get rid of the toxicity.
Strength of blowfish poison
The strength of blowfish poison is measured in "mouse units".
One mouse unit is a toxicity level that would kill a mouse with a weight of 20kg within 30 minutes. The lethal dose for human being is 5,000 ~10,000 mouse units. This is equivalent to only 2~3 mg of tetrodotoxin, which is nearly 100 times more poisonous than potassium cyanide. (Data from Ishikawa Health Service Association)
Where in blowfish is the poison located?
Generally, tetrodotoxin is contained in internal organs of blowfish such as the liver, bowels, stomach and ovaries. There are 70 kinds of blowfish near the Sea of Japan. In 1983, the Japanese Health, Labour and Welfare Ministry designated 22 kinds of blowfish as edible. Some blowfish have toxicity in their skin and muscle (meat), and the toxicity differs depending on the part. Accordingly, edible parts are specified in detail for each kind of blowfish.
Symptoms of Paralysis
It is said that blowfish toxicity paralyzes our nerves and muscles. What are the symptoms like and what should we do if we get them?
- Numbness appears in the mouth and tongue 20 minutes to three hours after eating the fish. Then, fingertips become numb and a headache and vomiting may follow.
- Anesthesia, motor paralysis, speech disability and breathing difficulty occur and blood pressure decreases.
- The entire body becomes paralyzed.
- In the final stage, the person loses consciousness. The patient dies due to paralysis in the breathing center.
If you feel paralyzed after eating blowfish:
- Bring up what you have eaten, and do so repeatedly by drinking a lot of cold water or warm water, sodium bicarbonate water, or salty water to empty the stomach.
- Take a rest and see a doctor immediately.
- The physician washes the stomach and injects Ringer solution or glucose intravenously. Then, artificial breathing is conducted, and medicine to elevate blood pressure, and a respiratory stimulant are given as symptomatic treatment.
To prevent poisoning
There is no effective treatment for blowfish poisoning and only the symptomatic treatment above is conducted. Since blowfish toxicity is nonimmune, it cannot be treated with blood serum as in the case of snake toxicity. Accordingly, avoid being poisoned?do not eat the poisonous parts of the fish. The Japanese Health, Labour and Welfare Ministry designates the kinds and parts of blowfish that do not affect our health when processed properly. In addition, only qualified persons and authorized facilities can process blowfish, and the sale of unprocessed blowfish is prohibited.
Special knowledge is required to cook blowfish. It is very dangerous for you to cook blowfish that you have fished or that has been given to you by a friend.
Never cook or eat blowfish at your own discretion.