It is true that the major ways people are exposed to toxins are by ingesting them, inhaling them, injecting them, or absorbing them through the skin.
Step-by-step explanation:
Toxins can enter in four various ways into our body often referred as "route of exposure". It is one among many factors affecting toxicity.
Inhalation: When the toxin is a gas, it is usually absorbed into the body by inhalation. Inhalation of toxins may cause respiratory and lung damage. Eg: cigarette smoke
Absorption: If a toxin enters the human eye or skin, it can be absorbed into the bloodstream. This is called absorption. The skin can prevent some toxins from entering the body. For example: work stations (gas stations) where people work with toxins
Ingestion means that the person has ingested the toxin. Some chemicals cannot get into blood from digestive tract. For example: drinking contaminated water.
The injected toxin enters the body when the person carrying the toxin breaks the skin. Injections can end in veins, muscles or just under the skin. Eg: Botulinum (used to get rid of wrinkles)
In bio-chemistry, poison, a natural or synthetic substance that damages living tissue and has a harmful or lethal effect on the body, regardless of whether it is absorbed, inhaled or injected through the skin.