Biomarkers in pediatric environmental health: a cross-cutting issue.

It is not yet known the extent to which the environment adversely affects the health of the developing individual. Difficulties in this determination are the problems of a) the assessment of exposure, b) the long latency of many diseases induced by the environment, c) the number of confounding exposures, and d) the extrapolation of animal models to critical stages of human development. Biomarkers have the potential to be quantitative dosimeters of exposure and biologic effective dose, as well as early warning signals of biologic effect. Biomarkers may document interindividual susceptibilities, as well as defining critical windows of exposure. To be useful, biomarkers need to be validated in terms of their specificity and sensitivity. Biomarkers are useful across all disciplines including asthma and respiratory problems, developmental neurotoxicity, childhood cancer, and endocrine disruptors. Biomarkers have not been developed nor used widely in pediatric environmental health. Research by our group and others has documented the validity of biomarkers in pediatric environmental health. Advances in the field of biomarkers may have important implications for the detection, prevention, and treatment of environmentally induced diseases in children. Ongoing validation of promising biomarkers should be a research priority.