A Glyphosate-Based Formulation but Not Glyphosate Alone Alters Human Placental Integrity

Area of Science:

• Environmental Toxicology
• Reproductive Toxicology
• Cell Biology

Background:

• Glyphosate (G)-based herbicides, notably Roundup (R), are widely used pesticides with potential exposure for pregnant women.
• Formulations contain G as the active ingredient and undeclared 'inert' formulants, which may possess greater toxicity.

Purpose of the Study:

• To compare the toxicity of glyphosate alone versus a glyphosate-based formulation (Roundup) on placental function.
• To investigate the role of formulants in the observed toxicity.

Main Methods:

• Utilized an ex vivo placental perfusion model to assess placental permeability and fetal venous flow.
• Employed immunohistochemistry to evaluate fetal vessel integrity after exposure.

Main Results:

• Roundup, but not glyphosate alone, altered placental permeability and fetal venous flow rate.
• Formulants significantly decreased glyphosate transfer and caused destruction of fetal vessels.
• Evidence suggests formulants, not glyphosate, are the primary toxic agents in the formulation.

Conclusions:

• Undeclared formulants in glyphosate-based herbicides are likely responsible for significant placental and fetal toxicity.
• These findings challenge the focus on glyphosate alone and highlight the need to consider formulation components in pesticide risk assessment.
• The toxicity of formulants may contribute to adverse pregnancy outcomes in exposed mothers.