Atrazine is a popular organic-compound herbicide used widely in the world, used heavily in the United States, but banned in the European Union.
It is an effective pre- and post-emergence weed-killer, making it attractive to larger-scale agricultural operations where profit margins are thin, though it has been shown to cause negative health effects and it has contaminated groundwater widely, where it is most used. It has been shown to be an endocrine disruptor, interfering with hormone production, it may be carcinogenic and it has been correlated in epidemiological studies with low sperm levels in men.
Some studies show that the US federal standard for maximum exposure may be too high. Atrazine has been shown in studies to worsen rates of birth defects, lower birth defects and menstrual problems for woman. A large study begun in 1998, the National Cancer Institute’s Agricultural Health Study, concluded that atrazine could not be conclusively link to causation of cancer.
Its use is supported in the US by lobbying groups that are comprised of agricultural states trade groups who refute any negative impact it may have. Agsense.org, for instance, is a lobbying website for the Triazine Network, a coalition of large statewide trade associations.
Wheat showing herbicide damage caused by the presence of residues from the application of a triazine (such as atrazine).
In amphibians, atrazine is a teratogen, causing demasculinization in male northern leopard frogs. In 2010, a study showed that atrazine made 75 percent of male frogs sterile and turned a tenth into females. A US Geological Survey the same year observed adverse effects on the reproductive abilities of fish from atrazine exposure below the federal guideline for exposure.
Right along, these studies and others have been refuted and others have deemed atrazine safe for use. The issue surrounding its application has become politicized and in the US, there is a revolving door between powerful private individuals and groups becoming government regulators regarding industries they have strong ties to and seeming conflicts of interest their stated goals in the private sector, compared with the job and standards that they are charged with upholding. Sadly, this conflict leaks into scientific study and prevents public interest from adequately being met.
The European Union, which uses a codified version of the scientific “precautionary principle,” in which the burden of proof that something is not harmful falls on those who wish to implement something, has banned atrazine, due to these inconclusive results.