Atrazine: A selective triazine herbicide. Inhalation hazard is low and there are no apparent skin manifestations or other toxicity in humans. Acutely poisoned sheep and cattle may show muscular spasms, fasciculations, stiff gait, increased respiratory rates, adrenal degeneration, and congestion of the lungs, liver, and kidneys. (From The Merck Index, 11th ed)Herbicides: Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.Simazine: A triazine herbicide.Soil Pollutants: Substances which pollute the soil. Use for soil pollutants in general or for which there is no specific heading.Triazines: Heterocyclic rings containing three nitrogen atoms, commonly in 1,2,4 or 1,3,5 or 2,4,6 formats. Some are used as HERBICIDES.Biodegradation, Environmental: Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.