Poisons
are
substances
which cause
death
or
injury
when taken in by a living thing
.
[1]
[2]
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 or inhaled). Substances which are poisonous are called
toxic
, but any substance can be toxic if too much of it is consumed. 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 behavior, problems with speech, and different forms of
amnesia
. This effect is called
intoxication
. People who drink even more may go into
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. 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
medication
. In high doses, atropine is a poison. Yet, atropine is a
core
medicine in the
World Health Organization
's "
essential drugs list
".
[3]
There are other types of dangerous materials. These are:
Pollution
is also sometimes poisonous, for example
toxic waste
.
In
wars
, some countries use
poison gases
against their enemies. This is called
chemical warfare
.
Poison gases such as
chlorine gas
and
mustard gas
were used in
World War I
. In World War II, the
Nazis
used a form of
hydrogen cyanide
gas to
kill many people
in their
death camps
and
concentration camps
.
Poison gas has also been used to intentionally kill humans as a method of
death penalty
.
Being poisoned by gas sometimes happens accidentally. For example, a faulty
furnace
or
heating
system can cause
carbon monoxide
poisoning.
There are many types of poison gases. For example,
corrosive
poison gases cause serious
burns
to the skin, eyes, and
lungs
.
Nerve agents
are poisons that can kill by damaging the
central nervous system
.
Blister agents
cause severe blisters on the inside and the outside of the body.
Choking agents
make
fluid build up in a person's lungs
until they
drown
.
In 2010, poisoning resulted in about 180,000 deaths, down from 200,000 in 1990.
[5]
There were approximately 727,500 emergency department visits in the United States involving poisonings?3.3% of all injury-related encounters.
[6]