New Evidence Suggests Monsanto Larvicide Is To Blame For Birth Defects in Brazil

Zika virus may not be the culprit in huge increase in microcephaly cases but, rather, Monsanto larvicide used in Brazilian water supply.

Credit: The Odyssey Online

Credit: The Odyssey Online


A group of Argentine doctors, who call themselves Physicians in Crop-Sprayed Towns, has released a new report that is raising questions about the real cause of microcephaly in Brazil. Until now, the leading cause has been speculated and reported to be the Zika virus, a common virus spread by mosquitoes in the area, but many have questioned the validity of this claim.

The new report states that the true cause of the recent and alarming rise in cases of microcephaly, a congenital defect that causes abnormally small heads and incomplete brain development in babies, is a Monsanto larvicide that has been distributed throughout the affected areas since 2014.

The larvicide is produced and sold by Sumitomo Chemical, a partner of Monsanto’s. In an unusual fashion, since insecticides are typically sprayed on crops, the larvicide Pyriproxyfen was actually being added to Brazil’s water supply in an effort to combat the larva of mosquitos that carry the Zika virus.

Credit: Wikipedia

Credit: Wikipedia

The mosquitoes present in these regions carry a host of viruses that Brazil attempted to protect its citizens from, including dengue fever, chikungunya, and yellow fever. The presence of the larvicide stopped the development of mosquito larva in the drinking tanks to control the mosquito population. The report from Argentine doctors noted that the Brazilian Ministry of Health, who has so far maintained that Zika is to blame, failed to recognize that “a chemical larvicide producing malformations in mosquitoes has been applied for 18 months, and that this poison (pyriproxyfen) is applied by the State on drinking water used by the affected population.” This suggests that the malformations that the larvicide causes in mosquitoes is also what is causing the malformations for the human babies that are affected. Since the larvicide is in the water supply, it is highly likely that the pregnant women with the microcephalic babies were exposed to the larvicide.

One Brazilian state, Rio Grande do Sul, suspended the use of the larvicide in their water as a precaution after the Argentine report was released. The Brazilian government has denied the negative effects of Pyriproxyfen in their water and has continued to use it in the other 25 states.

Already 270 cases of microcephaly have been linked to Zika by sampling the blood, tissue, brains, and amniotic fluid of fetuses and babies diagnosed with microcephaly. Though this is significant, the amount of cases showing no link to Zika is alarming. The Washington Post reported that 4,180 alleged Zika-related microcephaly cases have been reported in Brazil since October 2015. The process to link Zika to microcephaly amongst spread out states and in poverty-stricken areas of Brazil has apparently proven to be slow and complicated, despite being called an epidemic, but after scrutinizing 732 of the present cases, over half were determined to either not be related to Zika. If the pattern of the cases remains the same for the rest of the thousands of cases, could it be that the Pyriproxyfen is the cause of the microcephaly in at least some of these babies?

Credit: Wikimedia Commons

Credit: Wikimedia Commons

bulletin published by WHO earlier this month stated that, “ZIKV has been identified in Africa over 50 years ago, and neither there nor in the outbreaks outside Africa, such an association with microcephaly has been reported. Many other potential factors need to be considered as the cause of the outbreak.” The organization also stresses that although it is being investigated, it has not been confirmed that Zika is the cause of these defects. An outbreak of Zika has also been reported in Colombia, where the water is not treated, where some 3,177 women have given birth with no cases of microcephaly being cited.

Though there have been no studies on Pyriproxyfen’s effects on human fetuses, there was a study performed on animals by the World Health Organization that indicated some effect on rabbit and rat fetuses. When rats were given high doses of Pyriproxyfen everyday, WHO reported “an increased frequency of skeletal variations … in fetuses.” In rabbits, these high doses resulted in signs of miscarriage and premature delivery.

Although the WHO found prenatal links to high doses of Pyriproxyfen, the EPA also did a study and did not find evidence of prenatal or postnatal in rats or rabbits, so the studies about the effects on fetuses are not conclusive. It seems that even if there are some prenatal effects of Pyriproxyfen, there would need to be a high dosage ingested daily to result in things like microcephaly. Ian Musgrave, an expert on neurotoxicology and pharmacology who is not associated with Monsanto, told the Huffington Post that someone would need to eat a teaspoon of the raw larvicide or drink 1,000 liters of the treated water everyday to see the defects we’re seeing today. Pyriproxyfen has also been used widely in the United States in items such as flea collars for pets with no adverse effects.

Sumitomo denies the allegations that it causes microcephaly and says there is “no scientific basis” for the Argentine doctor’s claims.

Monsanto, an agribusiness giant based in the United States, is one of the most hated corporations in the world. They are known and most hated for their production of genetically modified organisms (GMOs), distribution of herbicides, and huge influence over government because of their donations to political figures. Monsanto has lied in the past, specifically about the alleged safety of their GMOs, and it would be no surprise if they, and their subsidiary Sumitomo, were found to be lying about the effects of Pyriproxyfen in an effort to not be made liable for these birth defects. As for the need for a high concentration of the larvicide to produce any negative effects, there seems to be no dosage studies done in Brazil’s water supply to either confirm nor deny that the water had enough Pyriproxyfen to cause these defects.

What do you think about Monsanto’s possible involvement in this? Let us know what your thoughts are in the comment section below and share this article!


This article (New Evidence Suggests Monsanto Larvicide Is To Blame For Microcephaly in Brazil) is free and open source. You have permission to republish this article under a Creative Commons license with attribution to the author and TrueActivist.com.

To Top