Narrator: This is Science Today. How do you study cigarette smoke without having someone actually smoke cigarettes? That was the dilemma faced by Kent Pinkerton and his fellow researchers at the University of California, Davis, who wanted to study the effects of second hand smoke. Their solution:

Pinkerton: We've designed and constructed a machine that automatically smokes the cigarettes for us.

Narrator: The machine smokes every cigarette in precisely the same manner. The cigarettes are special research cigarettes.

Pinkerton: The reason we use research cigarettes is that we want to have them precisely the same composition today, tomorrow and next year when we're doing these studies.

Narrator: Pinkerton needs all that consistency because he wants results that other researchers can reproduce. Outside the lab, that's hard to get. People smoke different cigarettes in different places and different ways.

Pinkerton: So it would be very difficult to really understand what the effects are if the conditions are constantly changing.

Narrator: For Science Today, I'm Steve Tokar.