welcome back. there's a new report out concerning the dangers of secondhand smoke. researchers at the harvard school of public health found 6% of kids under 12 live with a smoker and those kids are more likely to have behavior problems such as attention deficit hyperactivity disorder. robert bizell is nbc news's chief health correspondent. did this look at secondhand smoke before health, during childhood or all of the report. >> that's one of the problems, exposure in the woom or household, but it gets down to thomas the fact that cigarette smoking is awful, it's awful obviously for the person who is taking it in but bad for the kids and it has not just wosk behavioral affects but affects future risk for cancer. one of the things we've come to appreciate in the last few