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Atrazine: the DDT of the new Millenium?


 
AQOB has been reporting on Atrazine since 2008.
February 2008: Croaking it - a new threat from Atrazine
June 2009: Atrazine update 2009    

 
Play  Atrazine: food chain reaction  wsaw9feb16.mp3  
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Dr Arthur White, from the NSW Frog and Tadpole Study Group (FATS) brings news of a herbicide that affects frogs – atrazine. This chemical is a commonly used herbicide in America and Australia, it being effective and relatively cheap. Atrazine was banned in Europe in 2003 because of the high rates of prostate cancer and breast cancer among people who lived in areas where it had been used. While a lot of it enters plants (it is a herbicide) some of it is washed into creeks, streams and in some cases town drinking water. 

 
There has been a lot of research in America recently because it has been discovered that atrazine has an undesirable effect on frogs. Tadpoles that lived in agricultural areas where atrazine has been used grew into frogs but produced tadpoles that had major sexual anomalies. This manifested itself in sterility, secondary sexual malformations and a gender imbalance. This was first discovered when a population of frogs was investigated because it was dying out. It was found that there were no males at all!

 
Eggs were collected and grown in a laboratory, the eventual tadpoles being both male and female. If, however, they were raised by the lab in the pond water where they were born, all of the tadpoles became female. An analysis of the water showed that the main pollutant was atrazine, even though it was present in very low concentrations (2-3 parts per billion). There have since then, been epidemiological studies done in these American agricultural areas, that have shown that the incidents of prostate cancer and breast cancer are higher in these areas. The US Environmental Protection Authority (EPA) has indicated it would like atrazine banned but vested government and vested commercial interests take the opposite view. The EPA has now begun a plebiscite in the form of forums to bolster their case, even though they are taking on the big chemical producers.

 
While it was thought that the low concentrations of atrazine would have no effects, the all-female frog populations are proving otherwise. Laboratory tests now show that atrazine also affects human embryological tissue but without a groundswell of support for a ban, the chemical will continue to be used in America – and Australia is following America’s lead.
High concentrations of atrazine do not adversely affect frogs or humans which is why it passed clinical trials. It is at the very low concentrations that atrazine is most potent on frogs (and humans).
These low concentrations are at the limit of sensitivity of our measuring devices and were assumed to be too low to be biologically active. This assumption was clearly false and raising questions about how the trial of such chemicals should be constructed in the future.
In America, atrazine is mainly used for crops like maize, sorghum and sweetcorn. 

 
Atrazine kills competing weeds but spraying results in atrazine also coming in contact with the crop plants. Traces of atrazine have been detected in these crops as well as in cattle that are fed on crop leftovers. Atrazine has also been found in sweetcorn sold to humans. Thus it seems that atrazine is causing a reaction in the food chain (?indeed - a food chain reaction).
Those who oppose the banning of atrazine in the USA argue that it would be commercial suicide to do this as there is no suitable alternative herbicide for the large-leaved broadacre crops.

 
Those arguing for it to be banned highlight that Europe has continued to produce these crops without atrazine and that human health is being relegated to second place behind the profits of multi-national chemical companies. 
As the arguments rage, more frogs perish, more humans succumb to cancers, growth defects and sterility. 



Dr Arthur White was interviewed for A Question of Balance by Ruby Vincent and supplied all images included on this page. Summary text by Victor Barry, February 2016. 

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