Poisoning

a morbid condition caused by the action of poison on the body and accompanied by disruption of bodily systems and functions.

In humans. Poisoning in humans may be acute or chronic. Acute poisoning is usually the immediate result of the action of massive doses of poison and is often accompanied by disruption of the functions of the vital organs. Chronic poisoning results from the prolonged action of poison in small doses or in concentrations; examples are the lead poisoning of typesetters and the mercury poisoning among workers employed in the manufacture of thermometers. In such cases, the poison accumulates within the body, resulting in harmful consequences.

Poisoning may be domestic, medicinal, or occupational. The same poison, for example, lead, may cause either occupational or domestic poisoning; cases of chronic lead poisoning have been reported from the use of jam stored in unfired clay jars whose glaze contained lead. The frequency of a given type of poisoning depends on the season, geographic region, availability of certain drugs, and many other factors. Thus, poisoning from sleep-inducing drugs, organophosphorus compounds, and narcotics has replaced domestic poisoning from caustics, which was very common in the past. Carbon-monoxide poisoning is very common both in industry and in everyday life.

Localized symptoms are caused by the action of the poison on the skin, respiratory tract, or mucosa of the stomach or small intestine. Resorptive symptoms produced by absorption of poison are diverse, since they depend on affection of the liver, kidneys, blood, and the central and peripheral nervous systems.

Acute poisoning is often accompanied by dangerous disruptions of respiration, blood circulation, and the functioning of the liver. Emergency treatment should begin before the physician arrives. The stomach should be irrigated, vomiting should be induced, a purgative should be administered, and an enema should be given in order to evacuate unabsorbed poison as quickly as possible. If breathing ceases or the heart stops beating, artificial respiration or indirect heart massage must be administered. In hospitals, forced diuresis is used in order to discharge the poison circulating in the blood as soon as possible; with some types of poisoning, an artificial kidney is employed. Occupational poisoning may be prevented by observing rules of hygiene in industry and by having regular medical examinations. Domestic poisoning is prevented by keeping medications and strong solutions away from children and by keeping flue systems, geysers, and ranges in good working order.

In animals. Poisoning in animals is generally external in origin; for example, it can result from inhalation of contaminated air, or it can occur through the skin. There is no generally accepted classification. Poisoning in animals may be caused by food, medicine, or the bites of poisonous animals. It may also originate from poisonous plants and fungi or from mineral poisons. The third type of animal poisoning is marked by common clinical symptoms or by localization of the principal pathological process. This type affects the central nervous system, the cardiovascular system, and the gastrointestinal tract.

Fodder poisonings are extensively studied in veterinary science. They result from ingestion of fodder containing toxic matter, such as poisons, bacteria, fungi, and certain mineral poisons, for example, those found in pesticides. There are three types of fodder poisonings. The first type is caused by poisonous plants and their seeds entering the body together with coarse or concentrated fodders. It may also be caused by ordinary fodders that have developed poisonous substances as a result of improper storage or preparation. Another cause is immoderate or improper use of cotton, mustard, or other oilcake fodders containing traces of toxins. The second type includes poisonings caused by fodders infected with bacteria, toxic fungi, or granary pests. Of the last, the most important toxicologically are the granary weevil (Sitophilus granarius) and the grain mites of the family Acaridae. Poisonings of the third type are caused by synthetic urea, table salt, and other mineral substances used in fodder, as well as by carelessly stored chemicals used for controlling weeds, rodents, and harmful insects.

It is very difficult to diagnose poisoning. Diagnosis is based on a study of clinical and pathoanatomical symptoms; anamnestic data; and the results of chemical analysis of fodder, water, and excreta. Treatment is directed toward eliminating and neutralizing the poison and preventing its toxic effects. Poisoned animals must be slaughtered, and their flesh is examined in the laboratory to ascertain whether a residue of the poison remains; if so, the flesh is salvaged for nonalimentary use (for example, for making glues).