ABSTRACT
Toxic pollution originates from substances that cause alterations in the molecular and cellular functioning of organisms or in the entire organism. Organic pollution from agro-food industries followed in the 19th century, and subsequently there was pollution from dissolved salts, organic micropollutants, radioactive substances, and water acidification. Saline pollution is most often caused by chlorides. Chlorides occur in significant quantities in domestic wastes, but especially in industrial wastes, where chlorine is associated with sodium, potassium, or calcium. When the excretion rate of a poorly biodegradable or non-biodegradable pollutant is lower than the rate of chronic contamination, the pollutant accumulates in the organism. Short-term toxicity tests cease to be valid when the toxic effect is due to the non-degradation of pollutants and its bioaccumulation in the tissues. Toxic heavy metals are essentially mercury, copper, lead, cadmium, zinc, cobalt, and chromium, in the form of salts.
