Red-Tide Poisoning

One of the toxins released by some dinoflagellates is known as saxitoxin. This is a water-soluble salt that attacks the human nervous system. Thus, it is classified as a neurotoxin. The New Encyclopædia Britannica reports that “toxins released into the water are irritating to the human respiratory system.” Beach resorts have had to close when red-tide toxins have been released into the air as a result of wave action.

Are you fond of eating shellfish and other seafood? Well, red tides can make shellfish that feed on the dinoflagellates poisonous. Infomapper magazine states that ‘bivalves and other shellfish like oysters, mussels, and clams pose the greatest danger because they are filter feeders and absorb more toxins than fish.’ However, “fish, squid, shrimps, and crabs . . . can still be safe for human consumption.” The reason? Red-tide toxins accumulate in the intestines of these creatures, and these are usually removed before cooking.

Still, there is need for caution when eating seafood—especially shellfish—taken from areas known to be contaminated by red tides. Such tides can cause a condition called paralytic shellfish poisoning, or PSP. If you have ingested red-tide toxins, you may feel symptoms within 30 minutes. The accompanying chart lists some of these symptoms. If not treated appropriately, PSP could culminate in respiratory paralysis, which can lead to death.

At present, an antidote for red-tide poisoning is still unknown. However, some emergency procedures have had a measure of success. Red-tide toxins may be removed from a patient’s stomach by inducing him to vomit. Gastric lavage through a stomach tube has also been used to expel the poisons. In some cases, artificial respiration is necessary. In the Philippines some feel that drinking coconut milk with brown sugar helps victims to recover faster.

[Box on page 24]

Symptoms of Red-Tide Poisoning

1. A tingling or burning sensation of the lips, gums, and tongue

2. Numbness and tingling of the face, which spreads elsewhere in the body

3. Headache and dizziness

4. An intense thirst and hypersalivation

5. Nausea, vomiting, and diarrhea

6. Difficulty in breathing, speaking, and swallowing

7. Joint aches and a feeling of lightness

8. Quickening of pulse

9. Muscle weakness and lack of balance

10. Paralysis of the body