Toxicants

thumb|336x336px|The Amanita muscaria mushroom, an iconic toxic mushroom.

A toxicant is any toxic substance, whether artificial or naturally occurring. By contrast, a toxin is a poison produced naturally by an organism (e.g. plant, animal, insect, bacterium). The different types of toxicants can be found in the air, soil, water, or food.

Micropollutants are substances that even at very low concentrations have adverse effects on different environmental matrices. They are an inhomogeneous group of anthroprogenic chemical compounds that is discharged by human to the environment. Commonly known micropollutants that might pose possible threats to ecological environments are, to name just a few: environmental persistent pharmaceutical pollutants and personal care products, pesticides, stimulants, persistent organic pollutants, and artificial sweeteners To date, most of the scientists have identified wastewater treatment plants