Bisphenol A (BPA) is a type of chemical used in certain plastics. Exposure to BPA is linked with reproductive disorders, birth defects, and even cancer. If you'd like to avoid getting exposed to this chemical, it's important to know which products contain BPA, especially ones that contain or come in contact with food or beverages. Most manufacturers of canned goods use BPA-lined cans--this stems from a time before the dangerous health effects were known. It's still difficult to get canned foods without BPA linings, even in organic products. One of the few manufacturers which does use cans without BPA is Eden Foods, except for their highly acidic tomato products. Learn more about BPA at Plastic Albatross.
BPA Danger may be greater from Tin Cans than Water Bottles article from Treehugger
A Survey of Bisphenol A in canned foods by the Environmental Working Group