Can atrazine turn a frog into a female?
Pesticide atrazine can turn male frogs into females. Atrazine, one of the world’s most widely used pesticides, wreaks havoc with the sex lives of adult male frogs, emasculating three-quarters of them and turning one in 10 into females, according to a new study by University of California, Berkeley, biologists.
What pesticides are killing frogs?
Atrazine, one of the world’s most widely used pesticides, wreaks havoc with the sex lives of adult male frogs, emasculating three-quarters of them and turning one in 10 into females, according to a new study by University of California, Berkeley, biologists.
Is atrazine the cause of decline in amphibians?
Though the experiments were performed on a common laboratory frog, the African clawed frog ( Xenopus laevis ), field studies indicate that atrazine, a potent endocrine disruptor, similarly affects frogs in the wild, and could possibly be one of the causes of amphibian declines around the globe, Hayes said.
Is atrazine killing the African clawed frog?
Though the experiments were performed on a common laboratory frog, the African clawed frog (Xenopus laevis), field studies indicate that atrazine, a potent endocrine disruptor, similarly affects frogs in the wild, and could possibly be one of the causes of amphibian declines around the globe, Hayes said.
What effect does atrazine have on frogs?
Extrapolating these results from mammalian cells to amphibians, Hayes argues that atrazine could feminize male frogs by promoting the conversion of male hormones to female hormones. The lowered androgens would interfere with voice box development, while increased estrogens would promote ovaries within the testes.
What does atrazine do to amphibians?
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.
What does atrazine do to men?
The study concludes that atrazine exposure interferes with and reduces the production of male hormones (androgens) while increasing the effect and production of estrogen (female hormones).
How does atrazine cause feminization?
Atrazine demasculinizes male gonads producing testicular lesions associated with reduced germ cell numbers in teleost fish, amphibians, reptiles, and mammals, and induces partial and/or complete feminization in fish, amphibians, and reptiles.
Does atrazine change gender?
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.
Can a frog change its gender?
Frogs can change their sex even in pristine, pollution free settings. Past research suggested that male-to-female sex changes happening in frogs in suburban ponds may be caused by increased levels of estrogen released into the water. They found more female frogs than males in suburban areas.
Why we should not use atrazine?
It's so dangerous to both people and wildlife that it has been banned by the European Union. Numerous studies have provided overwhelming evidence linking atrazine to significant health concerns including increased risk of prostate cancer and decreased sperm count in men, and a higher risk of breast cancer in women.
Why was atrazine banned?
Research has linked atrazine to birth defects and cancer in people, and even miniscule doses can chemically castrate frogs. It has been banned or is being phased out in more than 35 countries but is the second-most commonly used herbicide in the United States.
What are the side effects of atrazine?
Symptoms may include a runny nose. It is not considered an eye irritant but swelling or redness may occur if it gets in the eyes. Skin exposure to atrazine may cause mild irritation, redness, or swelling. Atrazine is low in toxicity if it touches the skin.
What causes male feminization?
Gynecomastia is one of the common symptoms of feminizing syndrome in males. Causes of feminizing syndrome are considered the increase of serum level of estrogen, prolactin, LH and hCG and testosterone deficiency.
How long does it take for atrazine to work?
Typically, Atrazine is a very slow-acting herbicide, and it can take up to 4 to 6 weeks after application to see desired results and death of the target weed.
Is atrazine same as Roundup?
“Atrazine is a hundred times worse than glyphosate, the active ingredient in Roundup, because it's an endocrine disruptor,” said Nathan Donley, a scientist at the Center for Biological Diversity, which has called for a complete ban of the chemical. “It can have huge impacts and should have been banned a long time ago.”
How does atrazine affect animals?
Atrazine has been shown to cause changes in blood hormone levels in animals that affected the ability to reproduce. Some of the specific effects observed in animals are not likely to occur in occur in humans because of biological differences between humans and these types of animals.
What are the dangers of atrazine?
Atrazine has a lot of adverse effect on health such as tumors, breast, ovarian, and uterine cancers as well as leukemia and lymphoma. It is an endocrine disrupting chemical interrupting regular hormone function and causing birth defects, reproductive tumors, and weight loss in amphibians as well as humans.
What is atrazine and why is it harmful if it is in the water?
Atrazine is a surface water and groundwater contaminant that can enter waterways in agricultural runoff from row crops. Atrazine may cause human health problems if present in public or private water supplies in amounts greater than the drinking water standard set by EPA.
Is atrazine still used today?
Atrazine is widely used on corn and other crops to control grass and broadleaf weeds. It is also used on residential lawns.
What did Hayes study?
Hayes's studies in the early 2000s were the first to show that the hormonal effects of atrazine disrupt sexual development in amphibians. Working with the African clawed frog, Hayes and his colleagues showed in 2002 that tadpoles raised in atrazine-contaminated water become hermaphrodites - they develop both female (ovaries) and male (testes) gonads. This occurred at atrazine levels as low as 0.1 parts per billion (ppb), 30 times lower than levels allowed in drinking water by the EPA (3 ppb).
Why are atrazine and other hormone disrupting pollutants a likely contributor to the decline in amphibians?
In last week's issue of the Journal of Experimental Biology, Hayes and colleagues published a review of the possible causes of a worldwide decline in amphibian populations, concluding that atrazine and other hormone-disrupting pollutants are a likely contributor because they affect recruitment of new individuals and make amphibians more susceptible to disease.
How much atrazine is used in corn?
Some 80 million pounds of the herbicide atrazine are applied annually in the United States on corn and sorghum to control weeds and increase crop yield, but such widespread use also makes atrazine the most common pesticide contaminant of ground and surface water, according to various studies.
What did Hayes discover about frogs?
Coincidentally, another lab in 2008 discovered a sex-linked genetic marker in Xenopus, which has allowed Hayes to confirm the genetic sex of his frogs. In Hayes' study, where 40 frogs lived for about three years after hatching in water with 2.5 ppb atrazine, about 10 percent of the frogs appeared to be resistant to the effects of the pesticide.
Why are the offspring of a castrated animal dead?
This union produced viable eggs and larvae that survived to metamorphosis and adulthood. Yet, because both animals were genetic males, the offspring were all males. (Tyrone Hayes photo) The 75 percent that are chemically castrated are essentially "dead" because of their inability to reproduce in the wild, reports UC Berkeley's Tyrone B.
Why did Roger Liu develop a line of all-male frogs?
To overcome this, Hayes' colleague Roger Liu developed a line of all-male frogs so that the genetics would be unequivocal.
What is the most widely used pesticide?
March 1, 2010. By: Robert Sanders. Atrazine, one of the world's most widely used pesticides, wreaks havoc with the sex lives of adult male frogs, emasculating three-quarters of them and turning one in 10 into females, according to a new study by University of California, Berkeley, biologists.
Atrazine changes frog sex
Research headed up by a professor at the University of California – Berkeley, has determined that exposure to the herbicide Atrazine turns male frogs into females.
Damages frog voice boxes
Dr. Hayes’ research began under the funding of Atrazine’s then-owner, Novartis in 1997. Dr. Hayes found that frogs exposed to 1/30th of the amount the EPA allows in our drinking water shrunk the voice boxes of frogs.
Are we exposed to Atrazine?
A 2009 investigation by the New York Times revealed that 33 million Americans have Atrazine in their drinking water. 2010 EPA data reveals contamination levels exceeding the federal limit in nine of ten states that monitor Atrazine levels.
REFERENCES
Hayes TB, Anderson LL, Beasley VR, de Solla SR, Iguchi T, Ingraham H, Kestemont P, Kniewald J, Kniewald Z, Langlois VS, Luque EH, McCoy KA, Muñoz-de-Toro M, Oka T, Oliveira CA, Orton F, Ruby S, Suzawa M, Tavera-Mendoza LE, Trudeau VL, Victor-Costa AB, Willingham E.
What is the most commonly used herbicide in the United States?
Atrazine is the most commonly used herbicide in the United States and probably in the world 1. Here we investigate the effects of exposure to water-borne atrazine contamination on wild leopard frogs ( Rana pipiens) in different regions of the United States and find that 10–92% of males show gonadal abnormalities such as retarded development and hermaphroditism. These results are supported by laboratory observations, which together highlight concerns over the biological effects of environmental atrazine on amphibians.
How many oocytes are in a frog's testicle?
a, Transverse histological cross-section (8 µm thick; stained with Mallory's trichrome stain) of the left gonad of a male frog collected from Carbon County, Wyoming (site 3), showing testicular oocytes (arrowheads). More than 30 oocytes are present in this section. Serial sections reveal that every lobule has at least one oocyte, and some lobules (as shown) have as many as three. Scale bar, 250 µm. b, Frequency of occurrence of gonadal dysgenesis (black; poorly developed testes that lack distinct lobules) and testicular oogenesis (hermaphroditism; red) in frogs collected from the eight different sites shown in Fig. 1. The water-borne contamination by atrazine (measured in p.p.b.) was: site 1, 0.14; site 2, 0.20; site 3, 0.20; site 4, 0.30; site 5, 0.80; site 6, 6.70; site 7, data not available; site 8, 0.5.
Does atrazine affect amphibians?
Applied to crop fields as a pre-emergent, atrazine contamination in water sources peaks with spring rains, which also coincide with breeding activity in many amphibians. Given the adverse effects of atrazine on the gonads of male frogs, this pattern of atrazine application may increase its impact on amphibian populations. In the light of growing evidence that these populations are in decline 10, the contribution of atrazine to this decline warrants further investigation.
Do authors declare competing financial interests?
The authors declare no competing financial interests.
Is site 2 or 3 more susceptible to atrazine?
It may be that intermittently exposed populations are more susceptible to atrazine- induced hermaphroditism, whereas continuously exposed populations undergo adaptive resistance.