Hormones are in the 1 part per billion. Having glycophosphate levels of 1 part per million may be the cause in the increases in animal tumors and cancers I have observed.
Expert response from Robert H. Poppenga, DVM, PhD, DABVT
Professor of Clinical Veterinary Toxicology and Section Head, Toxicology Laboratory at the California Animal Health and Food Safety Laboratory (CAHFS), School of Veterinary Medicine, University of California at Davis
Thursday, 09/05/2019 21:15
You mention hormones being active at parts per billion concentrations. So, what I think that you are asking is - if hormones are active at parts per billion and glyphosate is present at higher concentrations (i.e., parts per million) why isn’t glyphosate causing problems? Perhaps the best answer is that the activity (either a pharmacologic action or a toxic action) of chemicals (either a naturally occurring chemical such as a hormone [yes hormones are chemicals] or man-made chemicals [such as glyphosate]) varies considerably between chemicals and is dependent on how much of a chemical reaches a target in the body and the inherent sensitivity of the target to the chemical. Hormones interact extremely well with very sensitive targets in our bodies called receptors – thus very low concentrations can be effective. For other chemicals, the interaction with a target is not as strong or not as much of the chemical actually reaches the target due to less absorption from the GI tract or breakdown of the chemical by the liver or failure of a chemical to be delivered to a potential target (for example, a chemical can’t easily cross into the brain to cause damage). So, for each chemical there is what is called a “dose-response” that varies for each chemical – some chemicals, such as hormones, cause a response at very low exposures (parts per billion) and others causes responses at much higher concentrations (parts per million, or even higher). I think that it is important to point out that a number of experts have reviewed all of the data available for glyphosate (across many “doses”) and evaluated many targets (many “responses”, including occurrence of tumors) and have concluded that glyphosate does not cause cancer.