should the worker be offered an equivalent job in the same industry? Or should the workplace be cleaned up to protect even the most sensitive worker?
The relationship of group and individual risk to biologic markers is crucial. It is important, therefore, to inform research-study participants in advance of the degree to which the results will be interpretable at the group level as opposed to the individual level. Participants in such studies should be given test results that are presented and discussed in the context of variability within and between people in the normal (nonexposed) population and the study group. Participants in epidemiologic studies might resist or refuse invasive techniques for obtaining markers or resist providing markers obtained by techniques perceived to be not fully safe. Although the use of urine samples for marker detection might be universally accepted, attention should not be directed away from blood, other body fluids, or tissue as reliable sources of markers; accuracy and not convenience should be the driving force. Whatever the choice, it must be economically feasible.
It is anticipated that some characteristics or markers of susceptibility will define a population at high risk for developing renal or urologic disease in response to environmental or occupational nephrotoxicants. Identification of the susceptible populations and appropriate markers may be greatly facilitated by comparative studies in animals with the understanding that in both cases it is necessary to consider precise definitions of markers of exposure, because susceptibility and exposure can be closely associated. In many cases before renal or urologic disease is clinically apparent, various markers of effect are present. These markers—which reflect cell injury, repair, growth, differentiation, or death—facilitate early intervention with the hope that disease progression can be slowed, halted, or reversed.
Chapter 2 provides information on the structure and function of the urinary tract, the diseases associated with the urinary tract, and their risk factors. In Chapter 3, relationships among exposure, susceptibility, and the associated markers are developed. The usefulness of markers in monitoring urinary diseases is discussed in Chapter 4. Chapter 5 develops a rationale based on epidemiologic studies for the use of biologic markers in protection of human health and extrapolation of data from animals to humans. New technologies and related issues are reviewed in light of research needs in Chapter 6. Chapter 7 summarizes the subcommittee's findings and recommendations.