Zinc is naturally present in water. The average zinc concentration in seawater is 0.6-5 ppb. Rivers generally contain between 5 and 10 ppb zinc. Algae contain 20-700 ppm, sea fish and shells contain 3-25 ppm, oysters contain 100-900 ppm and lobsters contain 7-50 ppm.
Cyanides (more exactly as cyanogenic glycozides) exist in cassavaroots, and fruit seeds as apricots, prunes, peaches, almonds etc. Cyanide is historically found in the seeds â¦of some fruits. Applesseeds contain cyanide, but a person would have to eat a lot ofapple seeds for the cyanide to have any negative effects. Cyanide is natural found in certain foods. This includes cassava,almonds, pits of some types of fruit, and Lima beans.
1 You could be exposed to cyanide by breathing air, drinking water, eating food, or touching soil that contains cyanide. 2  Cyanide enters water, soil, or air as a result of both natural processes and industrial activities. 3  When present in air, it is usually in the form of gaseous hydrogen cyanide. The extent of poisoning caused by cyanide depends on the amount of cyanide a person is exposed to, the route of exposure, and the length of time that a person is exposed. 2  Breathing cyanide gas causes the most harm, but swallowing cyanide can be toxic as well.