Poisons are substances which cause death or injury when taken in by a living thing. It may be taken in as drink or food, or absorbed through the skin. The damage is usually done by a chemical reaction. The effect of the poison varies with the amount which is absorbed (taken in). Substances which are poisonous are called toxic. If poisoning causes death, it is lethal poison.
Legally, and in hazardous chemical labeling, poisons are especially toxic substances. Less toxic substances are labeled "harmful", "irritant", or not labeled at all.
In medicine and zoology, toxins and venoms are different from poisons. Toxins are the result of a biological process. Venoms are substances which the organism uses to harm other species. Certain organisms use venoms for hunting, or as a defense. If an organism is poisonous, such as many mushrooms, it is harmful to eat. If it is venomous, like snakes or honeybees, it has a harmful bite or sting. For some very deadly bites humans have developed effective antivenoms.
Often it is only the quantity of a substance that makes the difference. Drinking alcoholic drinks may lead to aggressive behaviour, problems with speech, and different forms of amnesia. This effect is called intoxication. People who drink even more often are in shock. At the same time, alcohol can be used as a disinfectant.
Sometimes, poisons have an antidote. The antidote of a poison will slow or reverse its effects. Note that the antidote may itself be a poison. As an example, Atropine can be used as an antidote against certain nerve gases, like tabun or sarin, or against certain insecticides. It is also used as a drug, In high doses, Atropine is a poison. Atropine is a core medicine in the World Health Organization's "essential drugs list".
There are other types of dangerous materials. These are:
- Carcinogens, or cancer-causing poisons;for example acrylamide, asbestos, benzene
- Mutagens, or mutation-causing poisons such as radiation, benzene
- Teratogens, or birth defect-causing poisons; thalidomide, alcohol
Pollution also sometimes is poisonous. For example, large amounts of potato peeling scraps or milk can kill organisms in waterways, because they contain so much nutrients for microbes that the microbes consume all oxygen from the waterway.
Poison gas[change | change source]
In wars, some countries use poison gases against their enemies. Poison gases such as chlorine gas and mustard gas were used in World War I. Corrosive poison gases cause serious burns to the skin, eyes, and lungs. Nerve agents are poisons that can kill by damaging the nervous system.
Deaths[change | change source]
In 2010, poisoning resulted in about 180,000 deaths, down from 200,000 in 1990. There were approximately 727,500 emergency department visits in the United States involving poisonings—3.3% of all injury-related encounters.
References[change | change source]
- Concise Oxford Dictionary, 9th ed, p1055.
- Poison at Dorland's Medical Dictionary
- "WHO model list of essential medicines" (PDF). World Health Organization. 2005. http://whqlibdoc.who.int/hq/2005/a87017_eng.pdf. Retrieved 2006-03-12.
- "WHO Disease and injury country estimates". World Health Organization. 2004. http://www.who.int/healthinfo/global_burden_disease/estimates_country/en/index.html. Retrieved Nov 11, 2009.
- Lozano, R (2012). "Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the global burden of disease study 2010.". Lancet 380 (9859): 2095–128. doi:10.1016/S0140-6736(12)61728-0. PMID 23245604.
- Villaveces A. et al 2013. Causes of injuries treated in the emergency department, 2010. HCUP Statistical Brief #156. Agency for Healthcare Research and Quality.