Guiding principles for the use of biological markers in the assessment of human exposure to environmental factors: an integrative approach of epidemiology and toxicology. Report on a WHO consultation. WHO Regional Office for Europe.

Using biological markers can potentially improve the way in which exposure to environmental factors is assessed. At present, however, only a few valid biological markers are available that can be effectively used in epidemiological studies and the assessment of risk. Future application of biological markers requires collaboration between toxicologists and epidemiologists. To establish guiding principles in this field, the Bilthoven Division of the WHO European Centre for Environment and Health organized a consultation. The participants critically reviewed existing methods for the use of biological markers in assessing exposure, and discussed the justification and criteria for biomarker use, the limitations of biomarker-related assessments, confounder problems, aspects of study design, validation needs and ethical issues. Recommendations were made covering each of the topics discussed, and it is hoped that they will serve as guiding principles.