I had breast cancer nine years ago. I have a strong constitution--and a strong will--and those carried me far during my diagnosis and treatment. But still it was a difficult time for me and my family. One thing that brought me comfort was this thought: better that I was sick than one of my three daughters. What parent wouldn’t want to protect their children from such a trial?

The trouble is our job of protecting our children is getting harder, particularly shielding our daughters--and ourselves--from breast cancer. Why? Because one of the most pervasive chemicals in modern life has been linked to breast cancer.