Communicating their individual results to participants in an environmental exposure study: insights from clinical ethics.

The objective of this study was to formulate a framework for determining what information to communicate to individual subjects of a study measuring biomarkers of exposure, consistent with the principles of ethical clinical and research practice. Methods consisted of review of the scope of environmental exposure studies, including the use of biomarker measurement in clinical medicine and environmental research and the relevant principles of clinical ethics and research practice. An exposure biomarker study is designed to elucidate constitutional, behavioral, and environmental determinants of tissue concentrations of exogenous substances. Of itself, it is not designed to measure risk relations, those being the relation between biomarker levels and health outcomes. In many settings, measured tissue biomarker concentrations fall below those known or reasonably predicted to cause disease. Ethical clinical and research practice, aiming to maximize autonomy and beneficence and to minimize harm, requires that study findings concerning the determinants of exposure be communicated to study participants. In addition, investigators should reference clinical action levels beyond which individual biomarker results are routinely communicated to participants. When biomarkers have no known relation to risk, or when levels fall below action levels, it may be preferable not to communicate individual results, if this arrangement has been formalized at the time of informed consent.