THE DETECTION OF DNA ADDUCTS, DNA-BASE CHANGES AND CHROMOSOME-DAMAGE FOR THE ASSESSMENT OF EXPOSURE TO GENOTOXIC POLLUTANTS

The exposure of aquatic species to a variety of genotoxic chemicals raises the question as to the potential effects of exposure upon the health status of both current and future aquatic populations. The induction of DNA lesions in exposed species may initiate the formation of both structural and point mutations in genes, the modifications of which may lead to abnormality in both somatic and germ cells. The assessment of exposure levels of genotoxic agents and the genetic consequences requires the application of a set of inter-related techniques capable of providing both qualitative and quantitative information. In this paper we describe some methodologies available for the (a) assessment of genotoxin induced DNA adducts using the P-32-postlabelling procedure, (b) measurement of point mutations using the restriction site mutation assay and (c) the measurement of the production of chromosome structural and numerical aberrations using the micronucleus assay. This package of technologies may be optimised to use with individual species present in the aquatic environment to provide a cost effective package, capable of monitoring genotoxin exposure of individual environments.