Technical and Scientific Developmentsin Exposure Marker Methodology

Recent advancesin techniquesto measuremarkersof exposure to environmentaltoxicants in humans are changingthe ways inwhichenvironmental scientists, epidemiologists, and policymakerscharacterizeand interpretsuchexposure.In thisarticlewe reviewsomemajor technicalandscientific developments inexposuremarker methodologyfor estimatinginternaldose, with special referenceto studies conductedat the US Centers for DiseaseControland Prevention.We considerimportant characteristics of laboratorymethods,advancesin laboratorytechnology, analyticalstandards,andqualityassurance of laboratorymeasurements; comparisons with indirect methods for estimating exposures, such as exposureindicesand questionnaires; humanpharmacokineticdata; samplingproblems;surveillanceof human exposuresto toxicants;and interpretationof measurements.Witha viewto increasing the reliability ofexposure assessment,we make recommendations for obtaining moredata on humanexposureto toxicants.