The content of DDT in the water surrounding the algae is 0.02 per million parts of water. At what trophic level the concentration

The content of DDT in the water surrounding the algae is 0.02 per million parts of water. At what trophic level the concentration of DDT will be already dangerous:
seaweed -> roach -> perch pike -> human?

Through the cell walls, DDT will penetrate into the cells of algae and accumulate (with accumulation, a 10-fold increase in the concentration of poisons occurs), i.e., the concentration of DDT in the cytoplasm of algae will be 0.2. Inside the muscle tissues of roach (2nd level) the content of poison will increase to 2, perch (3rd level) – up to 20, pike (4th trophic level) – up to 200. Such fish will be very dangerous for human consumption. Thus, perch meat is no longer edible, because the accumulation of DDT in the human body after eating perch will be equal to 200.

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