S1, E3: New science is revealing breasts in a way that weve never seen them before. For years we've been seeking perfection. Gradually we are beginning to understand the wondrous biochemistry and evolution of the breast. But now some scientists believe breasts may be a hidden toxic waste ground, living time-bombs that might endanger not only their owners, but also those who suckle at them. Putting actual breast tissue - and breast milk - to the test we investigate if these wonderful life-giving organs are under threat from the modern world, and, if so, what we can do to save them.