The pace at which developments of biomarkers occur tends to exceed the biomonitoring community’s ability to cope with its obligations to ensure proper transmission of information on the meaning of the measurements. There are increasing anecdotal stories in the mass media about the concerns of people whose blood has been found to contain more than 100 chemicals. But the fact is that the numbers of studies, subjects, and substances determined in human biomonitoring are increasing (e.g., National Health and Nutrition Examination Survey), as is the awareness of the general public of those chemicals in our bodies (e.g., Sexton et al. 2004). Consequently, there is a need for clarification of what biomarkers can and cannot be used for. Despite proper warnings to the effect that “the measurement of an environmental chemical in a person’s blood or urine does not by itself mean the chemical causes disease” (CDC 2005), people who have almost unlimited access to good and bad information about chemicals no longer appear satisfied with such general words of caution. Not only is the general population entitled to know the advantages and limitations of biomonitoring