2.5.2. Herbicides

These chemicals are used to kill undesirable plants or “weeds”. Most of them will kill all the plants they touch, while some of them are designed to target one species. It is well known that herbicide application can pose a risk for the vegetation surrounding an arable field. Herbicides can cause environmental contamination such as air, soil and water. These herbicides can enter aquatic ecosystems as a result of terrestrial runoff, and to a lesser extent, of direct application and aerial spraying. Microbial communities in freshwater ecosystems are not directly targeted, but these communities are exposed to herbicides and can be directly or indirectly affected by these compounds.