Atrazine is the most commonly used herbicide in the U.S. and probably the world. It can be present at several parts per million in agricultural runoff and can reach 40 parts per billion (ppb) in precipitation. We examined the effects of atrazine on sexual development in African clawed frogs (Xenopus laevis). Larvae were exposed to atrazine (0.01–200 ppb) by immersion throughout larval development, and we examined gonadal histology and laryngeal size at metamorphosis. Atrazine (>0.1 ppb) induced hermaphroditism and demasculinized the larynges of exposed males (>1.0 ppb). In addition, we examined plasma testosterone levels in sexually mature males. Male X. laevis suffered a 10-fold decrease in testosterone levels when exposed to 25 ppb atrazine. We hypothesize that atrazine induces aromatase and promotes the conversion of testosterone to estrogen. This disruption in steroidogenesis likely explains the demasculinization of the male larynx and the production of hermaphrodites. The effective levels reported in the current study are realistic exposures that suggest that other amphibian species exposed to atrazine in the wild could be at risk of impaired sexual development. This widespread compound and other environmental endocrine disruptors may be a factor in global amphibian declines.

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Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically relevant doses.

The industrialization of the agricultural sector has increased the chemical burden on natural ecosystems. Pesticides are agrochemicals used in agricultural lands, public health programs and urban green areas in order to protect plants and humans from various diseases. However, due to their known ability to cause a large number of negative health and environmental effects, their side effects can be an important environmental health risk factor. The urgent need for a more sustainable and ecological approach has produced many innovative ideas, among them agriculture reforms and food production implementing sustainable practice evolving to food sovereignty. It is more obvious than ever that the society needs the implementation of a new agricultural concept regarding food production which is safer for man and the environment, and to this end, steps such as the declaration of Nyeleni have been taken.

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Chemical Pesticides and Human Health: The Urgent Need for a New Concept in Agriculture.

The herbicide atrazine is one of the most commonly applied pesticides in the world. As a result, atrazine is the most commonly detected pesticide contaminant of ground, surface, and drinking water. Atrazine is also a potent endocrine disruptor that is active at low, ecologically relevant concentrations. Previous studies showed that atrazine adversely affects amphibian larval development. The present study demonstrates the reproductive consequences of atrazine exposure in adult amphibians. Atrazine-exposed males were both demasculinized (chemically castrated) and completely feminized as adults. Ten percent of the exposed genetic males developed into functional females that copulated with unexposed males and produced viable eggs. Atrazine-exposed males suffered from depressed testosterone, decreased breeding gland size, demasculinized/feminized laryngeal development, suppressed mating behavior, reduced spermatogenesis, and decreased fertility. These data are consistent with effects of atrazine observed in other vertebrate classes. The present findings exemplify the role that atrazine and other endocrine-disrupting pesticides likely play in global amphibian declines.

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Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis)

https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=1370&context=bin_facpub

Demasculinization and feminization of male gonads by atrazine: Consistent effects across vertebrate classes

Atrazine is a common agricultural herbicide with endocrine disruptor activity. There is evidence that it interferes with reproduction and development, and may cause cancer. Although the U.S. Environmental Protection Agency (EPA) approved its continued use in October 2003, that same month the European Union (EU) announced a ban of atrazine because of ubiquitous and unpreventable water contamination. The authors reviewed regulatory procedures and government documents, and report efforts by the manufacturer of atrazine, Syngenta, to influence the U.S. atrazine assessment, by submitting flawed scientific data as evidence of no harm, and by meeting repeatedly and privately with EPA to negotiate the government's regulatory approach. Many of the details of these negotiations continue to be withheld from the public, despite EPA regulations and federal open-government laws that require such decisions to be made in the open.

European Union Bans Atrazine, While the United States Negotiates Continued Use

The effects of atrazine exposure on testicular sperm number, epididymal sperm number and motility and α-glucosidase activity in the epididymis were studied in Fischer rats. Histological changes in the testicular tissue were followed by light and electron microscopy. Groups of adult animals were treated i.p. with 60 and 120 mg atrazine kg−1 body wt. twice a week over 60 days. The results indicate a decrease in the body weight and relative weights of pituitary and ventral prostate vs control, measured on the last day of treatment in both treated groups. Testicular sperm number (expressed as number of sperm per 500 Sertoli cells) in atrazine-treated groups increased with the treatment time due to the reduced sperm motility. Therefore atrazine treatment provoked a significant decrease in sperm number and motility in epididymis, measured after the last day of treatment. α-Glucosidase activity in the epididymis, after the last day of treatment, showed a decrease in both treated groups vs control values. Histological analysis of testicular tissue from treated rats showed the cell disorganization and cell clusters together with spermatocytes. Electron microscopy presented differently vacuolated cytoplasm, collagen fibre was reduced, Leydig cells were of irregular shape with unequal form and cisternae of rough endoplasmic reticulum were accentuated and softly widened. In Sertoli cell cytoplasm, atrazine treatment provoked degenerative changes. According to the results obtained, it is evident that atrazine exerted morphological changes and a toxic effect on sperm and their motility. Copyright © 2000 John Wiley & Sons, Ltd.

Tomljenović A

Papers

Disorders of male rat reproductive tract under the influence of atrazine