Abstract
Traditionally, science has progressed by slow steps involving the accumulation of studies showing particular effects, leading eventually to a general consensus. However, with increasing development and industrialization, environmental problems have escalated faster than the ability to collect sufficient data to form clear consensus among scientists. Since managers require scientific information to make decisions about management, regulation, and public policy, the gap has been partially filled by two approaches: weight of evidence and the precautionary principle. I suggest that both are useful for making decisions about endocrine active substances, although few papers in the refereed literature link the precautionary principle with endocrine active substances. As with most public policy decisions, these involve an iterative process whereby scientific inquiry must continue to fill data gaps, and to determine if the decisions made by these processes are still appropriate and protective of human and ecological health. The precautionary principle is most useful when it continues to inform and help direct research to fill data gaps in our understanding of environmental problems, such as the effect of endocrine active substances on endocrine disruption.