Fish poisons, examples containing

Previously, this was done with pyrolusite, but modem processes use arsenic acid (with 2-aminoanthraquinone) and sodium m-nitrobenzenesulfonate (with 1-amino-anthraquinone). The sulfite can ako be removed by precipitation with alkaline earth chlorides, e.g., barium chloride. The procedure given above has the advantage that it yields a product which is practically ash-free. The ammonium chloride is added to neutralize the alkali formed in the reaction (the arsenite forrned acts as free sodium hydroxide). The mother liquors, which contain arsenious acid, are poisonous, of course, and must be handled carefully. They are usually treated with milk ef lime to render them harmless. The toxicity of such waste products is frequently ovo emphasized if they are discharged into large streams, for example, ftey rarely poison the fish. In plant operations, the excess anunonia is collected and used over without further treataent For a general discussion of the sulfonation of anthraquinone, see page 56 ff. 

Natural toxins include the most poisonous substances still known to man, and a few are several magnitudes more lethal than the best artificial nerve agents. The author considers the Pfiesteria piscicida microorganism to contain one of the most deadly toxins yet known, but much research needs to be done to confirm this. The author believes that this toxin is dangerous to health at less than one part per trillion. For example, one of these microbes can damage a quarter-sized spot of flesh on man or fish. Moreover, one such bite can disrupt the nervous system of a 10-lb rock-fish. Several bites on a man can cause neurological impairment, including short-term memory loss. 

Waste from factories. Waste liquid from some factories gets dumped straight into rivers. This waste may contain dangerous substances such as mercury or its compoimds. These do not kill fish, but get stored up in their bodies and eventually poison humans. Hair drops out and teeth rot. The victim becomes irritable and twitchy, and will die if not treated. Lead is another poisonous metal. It could leak out from factories that make car batteries, for example. But even more dangerous is the radioactive waste that may leak from nuclear waste processing plants, or nuclear power stations. 

---