Reporting needs for studies of environmental chemicals in human milk.

Studies of environmental chemicals in human milk have been carried out in many countries, but few have been conducted in the United States. These studies are useful for monitoring population trends in exposure to chemicals, for research into the determinants of environmental chemicals in milk and relationships between the levels found and the health status of the women and their infants, and for risk assessment. This article provides practical advice on data and information reporting for such studies. Participation in these studies comes at a difficult time for the breast-feeding mothers, so it is important that the mothers support the study and its goals. A key goal of any study of environmental chemicals in human milk must be to ensure that the breast-feeding process is not disrupted by unwarranted concerns about harm to the infant from chemicals in human milk. Therefore, it is essential that reporting of information be a two-way process. Information needs to be supplied to participating mothers before, during, and after their participation in the study. Information supplied before participation is necessary to satisfy the ethical requirement for informed consent; information supplied during participation includes advice on expressing, collecting, and storing milk samples, and how to avoid sample contamination; and information supplied to each participant at the end of the study includes a report of their individual results and a summary of study results and outcomes generally. The key instrument for obtaining data from the participants is the study questionnaire. This needs to be prepared in accordance with principles of good questionnaire development, and preferably should be interviewer administered. The questionnaire content will vary according to the objectives of the study. Although studies of environmental chemicals in human milk are logistically complex and demanding, they are practicable and, with careful planning and execution, yield important data.