Urine-sampling methods for environmental chemicals in infants and young children.

This review paper examines and evaluates urine-sampling methodologies in infants and young children, to determine which methods are suitable for use in large biomonitoring surveys or studies of environmental chemicals in children younger than 6 years. Methods for non-toilet-trained children include the use of urine bags, collection pads (e.g., cotton or gauze inserts), disposable diapers, cotton diapers, and the clean catch method. In toilet-trained children, collection methods include use of a commode insert pan as well as specimen collection cups. The advantages and disadvantages of these various methods need to be evaluated with respect to the target population, timing and frequency of collection, minimum sample volume required, method of urine extraction, potential for contamination of the sample, stability of the analyte of interest, and burden on participants and research team. Collection methods must not introduce contamination or affect the integrity of the sample, should be logistically practical, and should minimize discomfort experienced by the child. Although collection of urine samples from children who are not toilet-trained is more challenging than collection from older toilet-trained children, the vulnerability of younger children to the exposure to and health effects of environmental chemicals makes finding suitable methods a priority.