Toxic agents/poison

Any material or substance which can be damaging to the health and well-being of man (such as poisons/toxic agents, corrosive chemicals, flammable materials, explosives, radioactive materials). 

In experimental work, some accidental exposures, or in the administration of medicine, the dose may be a certain quantity of the chemical administered at one time, such as in a pill, an injection, or an accidentally swallowed poison. In industry, time is a factor in most exposures, and the dose is the result of both the concentration of the toxic agent and the duration of the exposure. 

Sunderman, F.W. 1970. Nickel poisoning. Pages 387-396 in F.W. Sunderman and F.W. Sunderman, Jr. (eds.). Laboratory Diagnosis of Diseases Caused by Toxic Agents. Warren H. Green, Inc., St. Louis, MO. 

Atropine is often used for colds for temporarily draining the nasopharynx. Atropine is also used in combination with other drugs as an antidote for poisonous anticholinesterase agents such as organophosphorous insecticides and neuroparalytic gases, hi such situations, atropine removes or balances toxicities that are a result of a high concentration of acetylcholine. 

Toxicant (poison) An agent cable of causing toxicity - a DDT, lead, noise,... 

It is useless for a non-toxic agent. There are few adequate studies on the matter with the limitation of using undifferentiated poisoned subjects and hence the value for lavage and its outcome are controversial. There is some evidence to suggest that it is effective and better than ipecac-induced emesis. 

Specific antidotes are available for only a few toxic agents (Table 7.2). Even these are not always effective, particularly if the poisoning is severe. The best treatment begins with supportive care. This includes resuscitation (if necessary) and maintenance of respiratory and cardiovascular functions. Imbalances in fluid and electrolytes may have to be corrected. An approach to the treatment of victims of poisoning is presented in Table 7.3. 

A general problem of microbial BOD-sensors could be poisoning of the cells by toxic substances in wastewater. One possibility to reduce or even to eliminate toxic effects on BOD-sensors is achieved by shortening measuring times down to not more than 1 min, in this way preventing toxic effects on the cells because of the short time of exposure to the toxic agents. 

Many foreign substances are ingested orally, either in the diet or as drugs, and poisonous substances taken either accidentally or intentionally. Most suicidal poisonings involve oral intake of the toxic agent. Consequently, the gastrointestinal tract is a very important site and perhaps the major route of absorption for foreign compounds. 

Consider the compounds with the structural formulas shown below. Which of these are believed to be the actual toxic agents involved in aniline poisoning Which are the forms eliminated from the body ... 

Pyrrolizidine alkaloids in the plant Senecio vernalis have been implicated in the poisoning of cattle.13 The toxic agents in this plant include three closely related alkaloids — senecionine, senkirkin, and seneciphyllin. The structural formula of senecionine is shown in Figure 19.2. 

Anyone who has been afflicted by poison ivy, poison oak, or poison sumac appreciates the high potential that some plant toxins have to irritate skin and eyes. The toxic agents in the plants just mentioned are catechol compounds, such as urishikiol in poison ivy. Contact with the poison causes a characteristic skin rash that may be disabling and very persistent in heavily exposed, sensitive individuals. Lungs may be affected — often by inhalation of smoke from the burning plants — to the extent that hospitalization is required. 

Chemicals are able to bring about both desirable and undesirable effects on organisms to which they are exposed, and the actions of medicines and poisons and toxic agents have been recognized for thousands of years. As a result of industrialization, modem man and the environment is now exposed to increasing numbers of chemicals. Because of their potential hazard, there is an appreciation of the requirement to assess the effects of these chemicals. Since chemical structure was elucidated (for a very brief history see Table 1.1), the relationship between chemical structure and... 

Mustard gas, Cl—CH2CH2 — S —CH2CH2—Cl, was used as a poisonous chemical agent in World War I. Mustard gas is much more toxic than a typical primary alkyl chloride. Its toxicity stems from its ability to alkylate amino groups on important metabolic enzymes, rendering the enzymes inactive. 

Members of the Borgia family, especially Cesare and Lucretia, were active poisoners in Rome in the Middle Ages and the papacy was probably an important financial beneficiary. A relative, Catherine de Medici, practised as a poisoner in France and was probably one of the first experimental toxicologists. Purporting to be engaged in charitable work, she experimented with her poisons on the poor and sick. She was able carefully to record important observations such as how rapidly the poison took effect, what parts of the body were affected, the symptoms in relation to the potency of the preparation of the toxic agent. 

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