Evaluation of Environmental Sample Analysis Methods and Results Reporting in the National Children's Study Vanguard Study.

During the initial Vanguard phase of the U.S. National Children's Study (NCS), about 2000 tap water, surface wipe, and air samples were collected and analyzed immediately. The shipping conditions, analysis methods, results, and laboratory performance were evaluated to determine the best approaches for use in the NCS Main Study. The main conclusions were (1) to employ established sample analysis methods, when possible, and alternate methodologies only after careful consideration with method validation studies; (2) lot control and prescreening sample collection materials are important quality assurance procedures; (3) packing samples correctly requires careful training and adjustment of shipping conditions to local conditions; (4) trip blanks and spiked samples should be considered for samplers with short expiration times and labile analytes; (5) two study-specific results reports should be required: laboratory electronic data deliverables (EDD) of sample results in a useable electronic format (CSV or SEDD XML/CSV) and a data package with sample results and supporting information in PDF format. These experiences and lessons learned can be applied to any long-term study.