Abstract
Concern about children's environmental health is increasing as newly characterized risks are identified. Often little data is available to guide policy decisions. Research on ambient exposures to environmental contaminants is essential to understand the magnitude and nature of risks to children's environmental health. However, the study of very young children is difficult due to logistical and societal limitations. The most successful field studies include recognition and accommodation of the study family's needs and the child's age and developmental-stage-specific characteristics. We will discuss specific elements to consider when designing and implementing field studies of pre-school children: site selection; development of the study plan and study team; screening and recruitment; informed consent; study implementation; data and sample collection; quality assurance/quality control; and study family communication.