Atrazine

Atrazine is prepared by reacting cyanuric chloride with ethylamine and isopropylamine .

The effect of atrazine is based on the inhibition of plant photosynthesis . It binds at the Q _B quinone binding site (the third link in the electron transfer chain of photosystem II after pheofetin and Q _A ) and interrupts electron transport. It breaks down relatively slowly in the environment, mainly due to hydrolysis.

The degree of toxicity of atrazine for different organisms is different. When exposed to humans and animals, the main impact falls on the endocrine system. Researchers suggest that it is an endocrine disruptor that causes hormonal imbalance ^[7] . Even at very low concentrations, it disrupts the ontogenesis of male frogs, turning them into hermaphrodites ^{[8] [9]} . Many researchers report that atrazine, apparently, not only reduces the production of testosterone , but also enhances the production of estrogen and, as a result, contributes to the development of breast cancer in humans ^[10] . So it was discovered that he is an agonist of the G-protein-bound estrogen receptor 1 ( GPER ) ^[11]

For birds and beneficial insects (such as bees ), as well as for soil organisms, this substance is largely safe. Atrazine practically does not accumulate in the food chain ^[12] .

In relation to humans, atrazine is a low-toxic substance. In isolated cases, irritation of the skin , eyes and respiratory tract is observed.

In countries where atrazine is still approved, it is used to selectively control weeds in the fields of corn , asparagus , potatoes and tomatoes.

Germany

The content of pesticides in groundwater is allowed no more than 0.1 μg ^[13] After the excess threshold is applied - for the long-term rehabilitation plan - this is an exception, the restriction is from 3 μg · l ⁻¹ . ^[14]

EU

Atrazine is banned in the European Union . The permissible daily dose is 0.02, the maximum permissible reference dose of 0.1 mg per kilogram of body weight per day ^[15] .

USA

EPA American Environmental Inspectorate Introduces 2007 Its Last report, believes that there is insufficient evidence of the harm of atrazine to amphibians. Since 2010, a comprehensive review was carried out taking into account the results obtained in 2007 ^[16] . This is due to the accumulation of decay products of atrazine in the drinking water of the corn belt ^[17] .

It is known that plants such as white gauze and bluegrass annual are resistant to atrazine and other herbicides from the class of triazines. This resistance is based on a point mutation in the psbA gene from the plastid genome , which encodes a Q _B binding protein. At position 264 of the peptide, glycine was replaced by serine, as a result of which the protein affinity for triazines was significantly reduced.

On October 31, 1986, about 400 liters of atrazine were discharged from Ciba-Geigy wastewater to the Rhine , which, combined with another accident involving a chemical spill as a result of an accident ( Sandoz Group in Basel ), caused a massive loss of fish in the Rhine a day later.

Since atrazine and its main decay product, desethylatrazine, seep into the groundwater and can thus contaminate drinking water , the use of atrazine in Germany has been prohibited since March 1, 1991 ^[18] , and in Austria since 1995. Nevertheless, it is still widespread in the environment; After a flood in Europe in 2002, it was increasingly found in the waters off Helgoland Island in the mussels and liver of a river flounder .

• Derivatives of triazines (1,2,4-triazinones and 1,3,5-triazinones)