Atrazine

Atrazine is a herbicide of the triazine class. Atrazine is used to prevent pre- and postemergence broadleaf weeds in crops such as maize (corn) and sugarcane and on turf, such as golf courses and residential lawns. It is one of the most widely used herbicides in US and Australian agriculture. Atrazine is a herbicide of the triazine class. Atrazine is used to prevent pre- and postemergence broadleaf weeds in crops such as maize (corn) and sugarcane and on turf, such as golf courses and residential lawns. It is one of the most widely used herbicides in US and Australian agriculture. As of 2001, atrazine was the most commonly detected pesticide contaminating drinking water in the United States.:44 Studies suggest it is an endocrine disruptor, an agent that can alter the natural hormonal system. However, in 2006 the U.S. Environmental Protection Agency (EPA) had stated that under the Food Quality Protection Act 'the risks associated with the pesticide residues pose a reasonable certainty of no harm', and in 2007, the EPA said that atrazine does not adversely affect amphibian sexual development and that no additional testing was warranted. EPA's 2009 review concluded that 'the agency's scientific bases for its regulation of atrazine are robust and ensure prevention of exposure levels that could lead to reproductive effects in humans'. EPA started a registration review in 2013. The EPA's review has been criticized, and the safety of atrazine remains controversial. Atrazine is a herbicide that is used to stop pre- and post-emergence broadleaf and grassy weeds in crops such as sorghum, maize, sugarcane, lupins, pine, and eucalypt plantations, and triazine-tolerant canola. In the United States as of 2014, atrazine was the second-most widely used herbicide after glyphosate, with 76 million pounds of it applied each year. Atrazine continues to be one of the most widely used herbicides in Australian agriculture. Its use was banned in the European Union in 2004, when the EU found groundwater levels exceeding the limits set by regulators, and Syngenta could not show that this could be prevented nor that these levels were safe. Its effect on corn yields has been estimated from 1% to 8%, with 3–4% being the conclusion of one economics review. In another study looking at combined data from 236 university corn field trials from 1986–2005, atrazine treatments showed an average of 5.7 bushels more per acre than alternative herbicide treatments. Effects on sorghum yields have been estimated to be as high as 20%, owing in part to the absence of alternative weed control products that can be used on sorghum. Atrazine was invented in 1958 in the Geigy laboratories as the second of a series of 1,3,5-triazines. Atrazine is prepared from cyanuric chloride, which is treated sequentially with ethylamine and isopropyl amine. Like other triazine herbicides, atrazine functions by binding to the plastoquinone-binding protein in photosystem II, which animals lack. Plant death results from starvation and oxidative damage caused by breakdown in the electron transport process. Oxidative damage is accelerated at high light intensity. Atrazine's effects in humans and animals primarily involve the endocrine system. Studies suggest that atrazine is an endocrine disruptor that can cause hormone imbalance.