Atrazine, introduced in 1958, is the most widely used pesticide in the United States. Between 70 and 90 million pounds of the active ingredient are used annually to combat weeds in agriculture, commercial, and domestic areas. It is used on lawns, playing fields, roadsides and golf courses. Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) is a chlorinated triazine herbicide used to control certain weeds in crops, particularly corn — sorghum — sugarcane — pineapple — macadamia nuts and citrus. Atrazine is the active ingredient in many herbicide products including Aatrex, Atrataol, Gesaprim and Zeophos, while it is a component of other herbicides including Alazine, Bicep, Bullet, Extrazine, Prozin, Rastra, Stuazine, and Tomahawk. (1,2)

The largest producer of atrazine has been the Ciba-Geigy Corporation that became Novartis, and is now Syngenta, the world’s largest agribusiness company with 6.3 billion dollars in sales of agrichemicals. Atrazine is also manufactured by E.I. duPont de Nemours & Co., Drexel Co., Oxon Italia, and Prodotti Chimici. Around 1970, only 12 years after being introduced, farmers were beginning to notice weed resistance to atrazine. By 1983 more than two-dozen weed species showed resistance to atrazine, and to other herbicides as well.

In spite of its wide use in this country; atrazine has been banned in most western European countries, with France announcing a ban in 2001 due to atrazine’s presence in water and risks to human health. (4)

Environmental Impact

A major environmental concern is atrazine’s mobility in soil and ground water. It has been found in the groundwater of 24 states, some of which do not even use the pesticide. The highest concentrations of atrazine were found in the cornbelt states of Illinois, Indiana, Iowa, Nebraska, and Kansas. It has been detected in 30 out of 33 samples of treated drinking water, indicating that it is not eliminated by ordinary treatment technology. More expensive activated charcoal filtration and ozonation are necessary for removing atrazine and its metabolites from drinking water.