Thursday, March 18, 2010

Atrazine Changes Male Frogs Into Female Frogs

Photo courtesy: WikiVisual

Atrazine is an organic compound widely used as a herbicide. Its use is controversial due to its effects on nontarget species, such as amphibians; and, because of widespread contamination of waterways and ground drinking water. Although banned in the European Union, it is still one of the most widely used herbicides in the world. Like many herbicides, it is sold under numerous trade names.

In late August of 2009, I published a report entitled "Poisoning The Well" that revealed the levels of atrazine in USA drinking water.

Atrazine has always been suspected to be a hormone-disrupting pesticide; but, a study done by some UC Berkeley zoologists (led by Tyrone Hayes) leaves no doubt now.

The study has shown that atrazine affects the male hormones. Affected male frogs can actually become totally physically female becoming able to mate and lay viable eggs. Wow...what could cause this?

The answer is very simple. It's atrazine - a chemical the EPA (Environmental Protection Agency) has been aware of for years; conducted experiments on for years; and, is now reinvestigating the matter. Atrazine is considered by many knowledgeable people to be the most toxic herbicide in the world. It is also the second most commonly used herbicide in the world and one of the most common man-made chemicals found in USA waters.

Not surprisingly, atrazine's manufacturer, Syngenta, deny that there is any risk surrounding the trace amounts found in water - whether drinking water or not. They swear there is no risk to either people or animals from the chemical despite a growing body of evidence that supports there is an incredibly significant risk to males due to its ability to interfere with the endocrine system.

Interference with the endocrine system leads to alterations in the hormone levels. Fish, birds, rats and frogs have signs of feminization when exposed to levels of atrazine. Some have developed female traits and/or body parts.

The frogs involved in Tyrone Hayes' research have shown the most confirming evidence so far. The frightening results were that atrazine seemed to target males actually became female in everything; but, their genes. Again, not surprisingly, they were exposed at levels considered safe by Syngenta and the EPA.

Hayes and his team had taken 40 male African Clawed Frogs as tadpoles and put them into water containing 2.5 parts per billion of atrazine - the same level considered to be safe in drinking water. What happened?

Interestingly, 90% of the frogs developed low testosterone levels, suppressed mating behaviour, reduced sperm production; and, an overall decrease in fertility.

The other 10%? That's the really interesting bit. These tadpoles actually developed in "functionally female" frogs. They were female in everything; but, their genes.

These "females" were able to mate and lay eggs that hatched into a new generation of frog. The only problem with the new generation was that they were all male; not a female to be found anywhere. How could this happen? Remember those genes? Both parents had only male genes to contribute to the developing embryo; so, the tadpoles had no biological option to be anything other than male.

I'm sure there is a little group of conspiracy theorists out there somewhere claiming to all who would listen that it's some nefarious scheme to eliminate the women of the world eventually; but, I tend to doubt it. Well...maybe...

What I do know is that I don't want to drink, bathe in, shower in, cook with, or in any other way come in contact with water that can turn a male African Clawed Frog into a female impostor.

Hayes believes the atrazine is absorbed through the frogs' skin and produces an enzyme that converts testosterone into estrogen. This, in turn, floods the frogs' bodies with the wrong chemical signals. Despite concerns by environmental activists, the EPA withdrew their initial concerns surrounding atrazine a few years ago. Fortunately, they have begun to reevaluate the potential health threats again.

It turns out now that a completely separate study is now linking atrazine use with obesity. Apparently, the greater the exposure, the higher the weight.

Why can't we just ban it?


Atrazine said...

Atrazine degrades in soil by the action of microbes. The half-life of atrazine in soil is 13 to 261 days. Atrazine biodegradation can occur by two known pathways: 1) Hydrolysis of the C-Cl bond, followed by the ethyl and isopropyl groups, catalyzed by the hydrolase enzymes called AtzA, AtzB, and AtzC.

Tyrone Hayes said...

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.

Atrazine Water said...

Life without atrazine would complicate weed management in corn, especially for sweet corn growers. A study at the University of Illinois looked at 175 sweet corn fields in the Midwest to find out just how important this 50-year-old, broad-spectrum herbicide is in sweet corn grown for processing.