Toxic compounds in herbicides without glyphosate

Food Chem Toxicol. 2020 Dec:146:111770. doi: 10.1016/j.fct.2020.111770. Epub 2020 Oct 4.

Abstract

Glyphosate has been banned in some herbicidal formulations. We analyse for the first time 14 marketed products in Europe where glyphosate was replaced by acetic, pelargonic, caprylic or capric acids, or even benzalkonium chloride, to be supposedly less toxic. 35 heavy metals, 16 polycyclic aromatic hydrocarbons (PAHs), and essential minerals were tested by specific mass spectrometry associated with gas chromatography or inductively coupled plasma methods in the formulations. Essential minerals do not reach toxic levels, but heavy metals are found at levels up to 39 mg/L, depending on the product, and include silicon, arsenic, lead, iron, nickel, and titanium. Their presence at up to several hundred times the admissible levels in water may be due to nanoparticles embedding pesticides. PAHs reach levels of 32-2430 μg/L in 12 of the 14 samples; for instance, the carcinogen benzo(A)pyrene was detected. It was found to be present at up to several thousand times above the norm in water, as was benzo(A)anthracene. These compounds did not add significant herbicidal effects. Low levels of glyphosate were detected in 2 samples. These variable levels of undeclared toxic chemicals violate European Union rules on pesticides and may have health and environmental consequences, especially when exposure is long-term.

Keywords: Glyphosate; Glyphosate-free herbicide; Heavy metals; Polycyclic aromatic hydrocarbons; Roundup; Toxicity.

MeSH terms

  • Environmental Monitoring / methods
  • Glycine / analogs & derivatives
  • Glycine / chemistry
  • Glycine / toxicity
  • Glyphosate
  • Herbicides / chemistry
  • Herbicides / toxicity*
  • Mass Spectrometry / methods
  • Metals, Heavy / analysis
  • Polycyclic Aromatic Hydrocarbons / analysis

Substances

  • Herbicides
  • Metals, Heavy
  • Polycyclic Aromatic Hydrocarbons
  • Glycine