Narrator: This is Science Today. For fifteen years, researchers at the University of California, Davis have been studying how air pollution affects lung structure and function. Kent Pinkerton, director of the UC Davis Center for Health and the Environment, is particularly interested in understanding how particles are deposited in the lungs, how they change location and what their fate may be over time.

Pinkerton: And especially, how that may impact on a rapidly growing lung system in the neonatal stage and I think this is an area where we can do a tremendous amount of research.

Narrator: In fact, Pinkerton's research group recently described in unprecedented anatomical and biochemical detail how cigarette smoke can damage the lungs of unborn and newborn children. In particular, Pinkerton found that environmental tobacco – or secondhand smoke – affects a critical period of lung development, when millions of tiny cells called alveoli are being formed. For Science Today, I'm Larissa Branin .