1.   But certain synthetic chemicals, including organochlorines, mimic estrogens.

2.   But in the uterus, instead of acting as an estrogen blocker, tamoxifen actually mimics estrogen and can stimulate tumor growth.

3.   But Kloas warns that it is often difficult to tell to what extent chemicals that mimic estrogen will disrupt sexual development.

4.   Production of Kepone, which mimics estrogen, was stopped many years ago, after epidemiological studies showed that it caused infertility in the male workers who produced it.

5.   Some scientists have theorized that chemicals that mimic estrogen, the female sex hormone, may be to blame.