Herbicides And Birth Defects

After years of acceptance as a safe and effective weed killer, a popular herbicide is facing the guillotine as teratogenic—it causes malformations in an embryo or fetus. Initial investigations (in the 1970’s) into the safety record of the chemical, glyphosate, indicated that its safety to humans was guaranteed.  An organization called Earth Open Source has now indicted the chemical as a serious risk to public health while accusing the herbicide industry of hiding the truth for decades.

“Reports of neural defects and craniofacial malformations from regions where glyphosate-based herbicides (GBH) are used led us to undertake an embryological approach to explore the effects of low doses of glyphosate in development,” said researchers from the University of Buenos Aires, in Argentina (Paganelli 2010).  But even prior to this, sequestered research from 2007 showed that glyphosate induced fetal malformations in lab animals and “adverse reproductive effects in the male offspring of a certain kind of rat.” (Huffington Post 2011)  The basis for such concern is the interruption of retinoic acid signaling in the development of vertebrate embryos, where Pagnelli et al found that embryos of selected amphibians and chickens demonstrated “…a gradual loss of rhombomere domains, reduction of the optic vesicles, and microcephaly.”

First of all, the terms need description.  Rhombomeres are tiny parts of the neural tube that will become the central nervous system.  Optic vesicles are tiny sacs from which will develop the parts of the eye that actually see things.  Microcephaly is abnormal smallness of the head.  Now that we understand that these characteristics may befall an amphibian or a chicken, must we be concerned that the same could happen to a human embryo?  Could it happen to you or to one of your family from long-term exposure to glyphosate or a related substance?

One of the troublesome things about laboratory experiments is the deliberate exposure of lab animals to doses of chemicals at levels that are unlikely to contact a human.  However, it is a springboard for prudent conjecture, for it introduces the potential “what ifs” of the process.  Related animal testing in Brazil showed that exposure to large amounts of glyphosate caused death in half the study population (Dallegrave 2003), accompanied by severe developmental retardation of fetal skeletons.  A sensible question asks why this data has been kept under wraps for nearly a decade.  The sensible answer is that the chemical industry didn’t want this info to go public for fear of boycott and reprisal that would inflict fiduciary pain.  The industry response is to say that the test results remain unclear, but that might just depend on whose spectacles are covered with petroleum jelly.  After all, testing poisons directly on humans is not, well, um, human.

The EPA, a watchdog that some say wears an eye patch, evaluates biocides every fifteen years in a process called registration review.  Lots can happen in that time.  Glyphosate works on weeds and other plants that are not genetically modified to tolerate it.   That tells the consumer that wherever it is used, the food it protects against weed infiltration is probably a GMO, the long-term effects of which are yet unknown.  When the Argentine government pulled that nation out of recession in the 1990’s it relied on GMO soy to help.  Shortly thereafter, residents near those soy farms—where glyphosate was used—experienced adverse health they had not experienced before.  High rates of birth defects and cancer were among them.  But also, there was destruction of non-tolerant crops and livestock from drifting of the overspray.  Argentine officials were implored by a group of environmental lawyers to ban the glyphosate spray, but the ban was never adopted nation-wide, although several provinces restricted spraying near populated areas.

There is speculation that plants immune to glyphosate develop bacterial infections novel to their species, and that these bacteria pose a threat to animal husbandry by initiating miscarriages.  Corn and soy, the two most heavily genetically modified crops, suffer the most bacterial rampage.  There is a possibility that humans could be affected.  Don Huber, a retired plant pathologist from Purdue, told the agriculture department of these concerns early in 2011, but was offered no comment from the government, while being summarily dismissed by the maker of glyphosate in the United States.  Over a hundred glyphosate formulations are on the market, many made in Asia.  The glyphosate industry labels independent studies as bogus, incomplete, and short-sighted.  They do, however, offer their own research as alternatives.

So, what does retinoic acid have to do with this?  Retinoic acid is the metabolite of Vitamin A that controls growth and development.  If stymied, as happens in the presence of glyphosate, reproductive chaos ensues as hypogonadism and infertility.  We should feel comforted knowing that the glyphosate industry has everything under control.

http://www.huffingtonpost.com/2011/06/24/roundup-scientists-birth-defects_n_883578.html Chem Res Toxicol. 2010 Aug 9. Glyphosate-Based Herbicides Produce Teratogenic Effects on Vertebrates by Impairing Retinoic Acid Signaling. Paganelli A, Gnazzo V, Acosta H, López SL, Carrasco AE. Laboratorio de Embriologia Molecular, CONICET-UBA, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 3 degrees piso (1121), Ciudad Autonoma de Buenos Aires, Argentina.

Toxicol Lett. 2003 Apr 30;142(1-2):45-52. The teratogenic potential of the herbicide glyphosate-Roundup in Wistar rats. Dallegrave E, Mantese FD, Coelho RS, Pereira JD, Dalsenter PR, Langeloh A. Department of Pharmacology, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Sarmento Leite 500 sala 202, 90046-900 Porto Alegre, RS, Brazil. elianed@vortex.ufrgs.br http://www.reuters.com/article/2011/02/24/us-monsanto-roundup-idUSTRE71N4XN20110224

Environ Mol Mutagen. 1998;31(1):55-9. 32P-postlabeling detection of DNA adducts in mice treated with the herbicide Roundup. Peluso M, Munnia A, Bolognesi C, Parodi S.

Environ Health Perspect. 2005 Jun;113(6):716-20. Differential effects of glyphosate and roundup on human placental cells and aromatase. Richard S, Moslemi S, Sipahutar H, Benachour N, Seralini GE. Laboratoire de Biochimie et Biologie Moleculaire, USC-INCRA, Université de Caen, Caen, France