Science And The Fracking Boom: Missing Answers

Living in the middle of a natural gas boom can be pretty unsettling. The area around the town of Silt, Colo., used to be the kind of sleepy rural place where the tweet of birds was the most you would hear. Now it's hard to make out the birds because of the rumbling of natural gas drilling rigs.

The land here is steep cliffs and valleys. But bare splotches of earth called well pads are all over the place.

"That's the one I'm worried about because it just went in," says Tim Ray.

Kay Allen had just started work, and everything seemed quiet at the Cornerstone Care community health clinic in Burgettstown, Pa. But things didn't stay quiet for long.

"All the girls, they were yelling at me in the back, 'You gotta come out here quick. You gotta come out here quick,' " said Allen, 59, a nurse from Weirton, W.Va.

Allen rushed out front and knew right away what all the yelling was about. The whole place reeked — like someone had spilled a giant bottle of nail polish remover.