A recent study by researchers at the University of La Plata, in Argentina, has found that most of the cotton hygiene products on the market contain the chemical glyphosate, widely used in agriculture as an herbicide. According to a recent World Health Organization statement, glyphosate is a probable carcinogen to humans.

The researchers purchased samples of cotton gauze, swabs, wipes and feminine care products including tampons and sanitary pads from stores in the La Plata area. Dr. Damian Marino, the study’s lead researcher, recounts the results: “Eighty-five percent of all samples tested positive for glyphosate and 62 percent for aminomethylphosphonic acid (AMPA), which is the environmental metabolite, but in the case of cotton and sterile cotton gauze, the figure was 100 percent.”

Marino adds, “In terms of concentrations, we saw that in raw cotton, AMPA dominates, with 39 parts per billion (PPB), followed by 13 PPB of glyphosate. While AMPA is absent in the gauze, the material contained glyphosate at 17 PPB.” The research was presented at the 2015 national Congress of Doctors of Fumigated Towns, in Buenos Aires.