Your body is probably home to a chemical called bisphenol A, or BPA. It’s a synthetic estrogen that United States factories now use in everything from plastics to epoxies — to the tune of six pounds per American per year. That’s a lot of estrogen.More than 92 percent of Americans have BPA in their urine, and scientists have linked it — though not conclusively — to everything from breast cancer to obesity, from attention deficit disorder to genital abnormalities in boys and girls alike. Now it turns out it’s in our food.