+Contamination is the unwelcome presence of a foreign [Substance](/wiki/Substance) within a material, body, or environment. This intrusion can compromise [Purity](/wiki/Purity), altering its state or rendering it unfit for its intended purpose.
+## See also
+- [Pollution](/wiki/Pollution)
+- [Toxicity](/wiki/Toxicity)
+- [Hygiene](/wiki/Hygiene)