Death rate from unintentional poisoning, OWID

A poison can be any substance that is harmful to the body. It can be swallowed, inhaled, injected or absorbed through the skin. Poisoning is the harmful effect that occurs when too much of that substance has been taken. Poisoning is not to be confused with envenomation. Acute poisoning is exposure to a poison on one occasion or during a short period of time. Symptoms develop in close relation to the degree of exposure. Absorption of a poison is necessary for systemic poisoning (that is, in the blood throughout the body). In contrast, substances that destroy tissue but do not absorb, such as lye, are classified as corrosives rather than poisons. Furthermore, many common household medications are not labeled with skull and crossbones, although they can cause severe illness or even death. In the medical sense, toxicity and poisoning can be caused by less dangerous substances than those legally classified as a poison. Toxicology is the study and practice of the symptoms, mechanisms, diagnosis, and treatment of poisoning. Chronic poisoning is long-term repeated or continuous exposure to a poison where symptoms do not occur immediately or after each exposure. The patient gradually becomes ill, or becomes ill after a long latent period. Chronic poisoning most commonly occurs following exposure to poisons that bioaccumulate, or are biomagnified, such as mercury, gadolinium, and

lead Lead is a chemical element with the Symbol (chemistry), symbol Pb (from the Latin ) and atomic number 82. It is a heavy metals, heavy metal that is density, denser than most common materials. Lead is Mohs scale of mineral hardness#Intermediate ...

. Contact or absorption of poisons can cause rapid death or impairment. Agents that act on the

nervous system In Biology, biology, the nervous system is the Complex system, highly complex part of an animal that coordinates its Behavior, actions and Sense, sensory information by transmitting action potential, signals to and from different parts of its ...

can paralyze in seconds or less, and include both biologically derived

neurotoxin Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and matur ...

s and so-called nerve gases, which may be synthesized for

warfare War is an intense armed conflict between State (polity), states, governments, Society, societies, or paramilitary groups such as Mercenary, mercenaries, Insurgency, insurgents, and militias. It is generally characterized by extreme violenc ...

or industry. Inhaled or ingested

cyanide Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...

, used as a method of execution in gas chambers, almost instantly starves the body of energy by inhibiting the enzymes in mitochondria that make

ATP ATP may refer to: Companies and organizations * Association of Tennis Professionals, men's professional tennis governing body * American Technical Publishers, employee-owned publishing company * ', a Danish pension * Armenia Tree Project, non ...

. Intravenous injection of an unnaturally high concentration of potassium chloride, such as in the execution of prisoners in parts of the United States, quickly stops the

heart The heart is a muscular organ found in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon diox ...

by eliminating the cell potential necessary for muscle contraction. Most biocides, including pesticides, are created to act as poisons to target organisms, although acute or less observable chronic poisoning can also occur in non-target organisms ( secondary poisoning), including the

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

s who apply the biocides and other beneficial organisms. For example, the herbicide 2,4-D imitates the action of a plant hormone, which makes its lethal toxicity specific to plants. Indeed, 2,4-D is not a poison, but classified as "harmful" (EU). Many substances regarded as poisons are toxic only indirectly, by toxication. An example is "wood alcohol" or methanol, which is not poisonous itself, but is chemically converted to toxic formaldehyde and

formic acid Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Est ...

in the

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...

. Many

drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhal ...

molecules are made toxic in the liver, and the genetic variability of certain liver

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

s makes the toxicity of many compounds differ between people. Exposure to radioactive substances can produce radiation poisoning, an unrelated phenomenon.

Treatment

If a person is suspected to have been exposed or ingested a poison, medical assistance to determine an appropriate treatment is necessary. If a suspected poisoning has occurred but the person is awake and alert, it is recommended to call the local poison information centre. If the person has collapsed or is having difficulty breathing, emergency medical assistance is required. To assist medical personnel, describe the person's symptoms, age, weight, other medications that person is taking, and any information about the poison. Try to determine the amount ingested and how long since the person was exposed to it. If possible, have on hand the pill bottle, medication package or other suspect container. The treatment will depend on the substance to which the patient is exposed. Depending on the type of poisoning, some first aid measures may help. Treatments include activated charcoal, induction of vomiting and dilution or neutralizing of the poison.

Prevention

Prevention strategies include locking up medicines and cleaners, reading labels on medicines and cleaners before using or storing, and safely discarding unneeded medicines, herbal supplements, and vitamins.

References

External links

{{Authority control Toxicology Poisons