Researchers from the University of California published a study last week in JAMA showing a 500% increase in the amount of the weedkiller glyphosate in the urine of adults from California studied from 1994 to the present. Authors attribute this increase to the introduction of GMO crops resistant to the weedkiller introduced in 1994 that are now widespread. People are then exposed through food and water contaminated with the chemical.
Glyphosate, marketed as Roundup, is also the most common backyard weedkiller.
This is a good time to stop using this chemical in your yard. Consider simple alternatives like
-killing with vinegar
-covering with black plastic that suffocates the weeds and cooks the seeds (the picture is me doing this in our yard).
-using a weed torch where sensible
-outcompeting with plants or seeds of plants that you want