Potassium dichromate increases the micronucleus frequency in the crayfish Procambarus clarkii.

The assessment of biological effects on aquatic vertebrate and invertebrate species is frequently employed to monitor water pollution because it provides meaningful information on bioavailability and effective concentration levels. Of special concern are genotoxic agents that induce DNA alterations at subtoxic exposure levels. With the objective of developing a field-assay for the detection of genotoxic pollutants in water, we investigated the effects of hexavalent chromium in the haemolymph cells of Procambarus clarkii using the micronuclei (MN) test. The frequency of micronucleated cells significantly correlated with the amount of potassium dichromate in water and with the amount of chromium found in gills.