Studies in Humans

Publisher Summary This chapter deals with techniques applicable to volunteers. Special emphasis is placed on studies in volunteers because this kind of study is less used and less well understood. It also comments selectively on pesticides that have been studied in humans, whether in connection with cases of poisoning, use as drugs, exposure of workers, or investigations in volunteers. The reason for performing some studies on humans rather than limiting them to animals is that species are not identical. For a given compound, the species factor is likely to involve a greater quantitative difference than any other factor in toxicity except dosage. Furthermore, species differences may be qualitative as well as quantitative. Since humans are unique in their response to chemical exposure, the introduction of a biologically active chemical into commercial use without first submitting it to careful observation in a limited number of people exposed to it under conditions controlled as carefully as possible has been questioned. There have been many changes in the nearly two decades since Dr. Hayes defined the ethics and methodology for using volunteers to study pesticides in humans, but the information in this chapter remains applicable and relevant for conducting such studies today. However, the EPA has recently addressed some of the issues and principles that were covered in the Hayes material, and there are now formal laws and regulations for some of these issues.