“…Although several techniques for identifying individual exposures have been developed and tested, and although more and more xenobiotics have been recognized to have teratogenic and mutagenic potential, "essentially no specific biomarkers are currently available to indicate that exposure to a given xenobiotic is directly associated with a cellular, subcellular, or pharmacodynamic event" (6). The paradox continues, despite continuing advancements in laboratory science and the growing recognition of the need for biological markers to improve exposure measurement in the field ofenvironmental epidemiology (3,4,(7)(8)(9).…”