Phenylurea herbicides: chemical properties and genotoxic effects.

A high number of herbicides is used to protect important crops, but an intensive use of these chemical compounds produces a general increasing of environmental pollution, and could be hazardous for human health. Thus, it is very important the identification of their mode of action, and the evaluation of their genotoxic properties, especially to assess the exposition level of people that come into contact via inhalation, skin contact, or ingestion of these compounds, and working in the areas where herbicides are used. Results concerning genotoxic activity of chemical compounds could be obtained using in vitro short term tests such as the evaluation of cytogenetic effects on exposed mammalian cell lines. Phenylurea herbicides are selective agents, widely used in agriculture for the control of weeds, belonging to C2 group of the Herbicide Resistance Action Committee (HRAC) classification, and are endowed by a mode of action that determines inhibition of photosynthesis at photosystem II complex. The genotoxic properties of some of these compounds were evaluated by a number of tests, including cytogenetic effects (chromosomal aberrations, and sister chromatid exchanges) on Chinese hamster cell lines. Here we present a review of chemical properties of the phenylurea herbicides, and their genotoxic effects evaluated with mutagenic assays.