Exposure (toxicology)
An example of a toxin which is often injected on purpose is Botulinum.  This is a very deadly toxin that causes botulism, but it is also sold under the name "Botox."  Many people choose to get Botulinum toxin injected into their faces to get rid of wrinkles.  The toxin paralyzes some of the muscles in the face, usually for three to 12 months, and makes the face look smoother.