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DEMONSTRATION OF LOW COST BURDEN, EXPOSURE MONITORING STRATEGIES FOR USE IN LONGITUDINAL COHORT STUDIES - VOLUME I - FINAL REPORT AND VOLUME II - APPENDICES
Citation:
Rench, J., J. Raymer, L. Thalji, M. Spruill, C. A. Salmons, L. Michael, M. J. Pecha, E. Dean, G G. Akland, AND R C. Fortmann. DEMONSTRATION OF LOW COST BURDEN, EXPOSURE MONITORING STRATEGIES FOR USE IN LONGITUDINAL COHORT STUDIES - VOLUME I - FINAL REPORT AND VOLUME II - APPENDICES. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-04/109 (NTIS PB2006-101283), 2004.
Impact/Purpose:
The primary objective of this study is to develop and demonstrate relevant, low cost, low burden monitoring strategies that can be used in a longitudinal epidemiological study that focuses on pregnant women and young children.
Description:
The Federal Government is currently planning a large, prospective birth cohort study known as the National Children's Study that will potentially involve 100,000 children and their families. The observation period will start as close to conception as possible and will continue for 20 years after birth. Given the magnitude and expense of such a large study, sample collection methods that are amenable to acquisition of samples exclusively by the participants themselves followed by direct shipment to the analysis laboratory present a cost-effective alternative to technician-based sampling procedures. In this pilot study, the ability of participants in three age cohorts to collect environmental and biological samples according to prescribed protocols was evaluated. The cohorts consisted of parents and their children in the ages of 0-1 year, 3-5 years, and 6-8 years old. Biological and environmental samples collected during the study included urine, hair, saliva, breast milk, duplicate diet, tap water, vacuum cleaner dust, floor surface dust wipes, air samples, cotton sock dosimeters, and humidity/temperature measurements. Sample collection instructions and materials were prepared, subjected to evaluation and modification using a test population, and shipped to participants over a 12-month period. Participants were requested to collect the samples, complete questionnaires, and return the samples to the laboratory within defined time periods. Upon receipt at the laboratory, the condition of the samples was assessed by visual inspection and the details of the receipt and evaluation were logged into a computer database; queries were subsequently used to assess compliance. In some cases, chemical analysis was used to further evaluate sample integrity.
The demonstration studies generated considerable information that favorably supports sample collection by study participants and remote data collection via the web, although the studies brought forward a number of issues that can impact a large-scale study such as the NCS. Completion rates for the different on-line surveys were 73% or better. For a relatively complex survey including pesticide use, the response rate was 92%. There was a 96% response rate for completion of a time/activity diary related to the participant child's exposure to pesticides in the home. Participant compliance with sample collection instructions appeared to be good for most sample types. One hundred percent of the hair samples and vacuum cleaner dust samples, for example, were considered to be acceptable. Acceptability rates were greater than 85% for breast milk, urine and food. But the number of acceptable beverage (diet) and tap water samples was lower due to return of leaking containers. The number of acceptable samples was substantially lower for the more complex sampling methods. All of the VOC air sampling badges were returned to the laboratory, but only 56% of the samples were determined to be acceptable. Although an instructional video was included with the badge, the participants found the sample collection method to be too complex. Samples were generally returned in a timely manner, in compliance with the instructions. Results of this project are very encouraging, indicating that remote data collection by study participants is feasible. Results can be used to develop strategies that will maximize completeness of sample collection while minimizing participant burden and study costs.
The U.S. Environmental Protection Agency through its Office of Research and Development funded and managed the research described here under Contract Number 68-D-99-012 to RTI International. It has been subjected to the Agency's peer and administrative review and has been apprpoved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.