Randomized controlled trials in environmental health research: ethical issues.

Randomized controlled trials (RCTs) are becoming increasingly common in environmental health research. Like all studies involving human subjects, environmental health RCTs raise many ethical challenges, ranging from obtaining informed consent to minimizing risks to protecting privacy and confidentiality. One of the most important issues raised by these studies is whether it is ethical to withhold effective environmental health interventions from research subjects in order to satisfy scientific objectives. Although environmental health investigators usually do not have professional obligations to provide medical care to research subjects, they have ethical obligations to avoid exploiting them. Withholding interventions from research subjects can be ethical, provided that it does not lead to exploitation of individuals or groups. To avoid exploiting individuals or groups, investigators should ensure that research subjects and study populations receive a fair share of the benefits of research.