Method description and initial results of a study to assess risks to health sector workers and environment due to chemical agents used and waste products generated in diagnostic clinical chemical laboratories, and image diagnostic testing. A survey was conducted of the methods and agents used and their toxicological classification, the number of workers exposed and an analytical profile of the waste produced. The assessment of risk to workers was based on cytogenetic tests (chromosome aberrations and micronuclei); the assessment of environmental risk from waste disposal was based on tests on plant systems.