Our primary exposure to estrogens is, of course, what we produce ourselves in the endocrine tissues and through peripheral aromatization of fat. However, we also obtain additional exposure from our environment, the vehicle being diet. We can divide dietary estrogen exposure into naturally occurring phytoestrogens, which you see on this side of the chart, and synthetic contaminants, shown on this side. Today’s talk will focus on the naturally occurring estrogens. We’ll leave the synthetic contaminants to the environmental epidemiologists.