Environmental Exposure Assessment in Children: Understanding the Challenges

Pediatric environmental health is an emerging field driven by mounting concern for the long term consequences of a child's exposure to a dramatically changing environment and the increase in chronic diseases in developed countries that cannot be explained by genetics alone. This article will look at some of the challenges that surround environmental exposure assessment in children by reviewing the history of pediatric environmental health, health indicators, science-policy issues, principles and methodology. Children have unique characteristics and developmental stage-specific vulnerabilities which affect exposure from chemical environmental contaminants. Children display differences to adults not only in physical size, but in anatomy, physiology, metabolism, toxicokinetics and behavior, all of which will influence intensity, frequency and duration of exposure to the toxicant. Most importantly, the timing of the environmental exposure can have significant sequelae. The effect of chronic, low dose exposure to chemicals over the lifetime of a child remains an unknown factor as do the health implications from exposure to a mixture of chemicals. A broad introduction to the types of chemical hazards which threaten childrens' health is followed by a discussion of tools which are used in exposure assessment with emphasis on the use of biomarkers as an internal dose measurement. Advances in technology are beginning to address some of the challenges in developing biomarkers relevant to the various developmental specific stages in children and therefore lead the way to improved exposure assessment, modeling and risk assessment of chemicals in children.