And we are not talking about visible dangers now: garbage, driftwood, broken glass. It’s clear to anyone in their right mind: you see an unkempt beach, even if it’s within walking distance — don’t even think about stopping here, it won’t be any better in the water.
We will talk about reservoirs that are outwardly harmless. But don’t be confused by the deceptive purity of the water. If you risk refreshing yourself in it, most likely, then you will have to consult a doctor.
The specialists told how to determine at a glance whether a lake, pond or other body of water is suitable for swimming.
Ducks, geese, seagulls
Many are sure that where there are waterfowl, the water is the purest.
«They feed on fish, and fish will not live in dirty water,» one fisherman argued with foam at the mouth.
But the fact is that ducks, geese, seagulls, and other such birds throw larvae into the water, which can cause serious illness.
«Cercariae — larvae of parasitic flatworms living in freshwater reservoirs are to blame for the rashes,» a dermatovenerologist of the highest qualified category, told Doctor Pack. — Cercariae like to parasitize waterfowl. But they can confuse them with a person, for example, instead of a duck paw, choose an arm or leg of a vacationer. They get under the skin, causing unpleasant symptoms: a painful, inflamed rash that looks like knots.»
If a lake or pond has bloomed and there are a lot of algae near the shore, it is better not to go into such a pond. You will get worms.
«There are conditions here for the attachment of various intermediate types of parasites,» doctor said. — For example, adolexaria, which are swallowed by animals at a watering hole. They can provoke a helminthic invasion by tapeworms of various types.
And blue-green algae, which are found, for example, in the Gulf of Finland, are extremely toxic! At the end of June, after bathing in such water, a young dog died. Veterinarians believe that the dog was poisoned by algae secretions and do not exclude that there is a danger for people.
These dangers await bathers not only in standing, but also in reservoirs with running water. Therefore, the same safety rules apply to rivers as to lakes and ponds.
Collective farm and landfill
Any agricultural land or piles of garbage near the reservoir are storm drains. This means that biogenic pollutants get into the water. It even sounds unpleasant, and suffering from an intestinal infection after this is even worse.
Highway and factory
«If there is an industrial enterprise or a highway near the reservoir, heavy metals can get into the water, experts warn. — They are washed away there by heavy rains. Such metals have a toxic effect and can cause poisoning of the body.»