Monuron

Past agricultural and industrial weed control; legacy residues in soil and sediment. In the U.S., pesticide registrations have been canceled, but contamination can remain where it was used [1][3].

Drinking private well water near formerly treated areas; contact with contaminated soil or dust; occupational handling or cleanup; residues on imported produce where still used [1][3].

Can irritate eyes/skin and cause nausea at high exposures; animal studies show liver and kidney effects. Not classifiable as to human cancer risk by IARC (Group 3). Can contaminate groundwater and harm fish and invertebrates [2][3][1].

Pesticide applicators and cleanup workers; people living near treated rights‑of‑way or fields; private well users in affected areas [1][3].

Test private well water for pesticides; use NSF/ANSI‑certified filters (activated carbon or reverse osmosis) that reduce pesticides; avoid using old monuron products; wash/peel produce; follow local water advisories [4][1][3].