Kolkata:Natural toxins are toxic compounds that are naturally produced by living organisms.These toxins are not harmful to the organisms themselves but they may be toxic to other creatures, including humans, when eaten. These chemical compounds have diverse
structures and differ in biological function and toxicity.
Some toxins are produced by plants as a natural defense mechanism against predators,
insects or microorganisms, or as consequence of infestation with microorganisms, such as
mould, in response to climate stress (such as drought or extreme humidity).
Other sources of natural toxins are microscopic algae and plankton in oceans or sometimes
in lakes that produce chemical compounds that are toxic to humans but not to fish or shellfish
that eat these toxin-producing organisms. When people eat fish or shellfish that contain these
toxins, illness can rapidly follow.
According to World Health Organization (WHO) some of the most commonly found natural
toxins that can pose a risk to our health.Aquatic biotoxins: Toxins formed by algae in the ocean and fresh water are called algal toxins. Algal toxins are generated during blooms of particular naturally occurring algal species.
Shellfish such as mussels, scallops and oysters are more likely to contain these toxins
than fish. Algal toxins can cause diarrhea, vomiting, tingling, paralysis and other effects in
humans, other mammals or fish. The algal toxins can be retained in shellfish and fish or
contaminate drinking water. They have no taste or smell, and are not eliminated by cooking
or freezing.
Another example is ciguatera fish poisoning (CFP) which is caused by consuming fish contaminated with dinoflagellates that produce ciguatoxins.
Some fish known to harbour ciguatoxins include barracuda, black grouper, dog snapper,
and king mackerel. Symptoms of ciguatera poisoning include nausea, vomiting, and
neurologic symptoms, such as tingling sensation on fingers and toes. There is currently no
