It's easy to let warnings about the risks of ubiquitous chemicals go in one ear and out the other—especially when that Franken-lipstick is the only one that doesn't come off on your Starbucks straw. Maybe we'll all take these words of caution more seriously when they roll off the tongue of Sean Penn, who narrates a new documentary called "The Human Experiment." The film attempts to draw connections between the growing number of untested chemicals we're all exposed to every day, and the increasing incidence of a wide-range of maladies, from infertility to autism. Do you think the risks of synthetic compounds have been overblown? Or is this just the tip of the iceberg? Sound off in the comments.