I think there full of shit. My mom has smoke cigs since she was young. She just turned 71 and has lymphobic lung cancer and the dr's say it wasn't from smoking. She took care of the parks In Center ND, small town, and what there saying is that the spray she had to use for weeds and leafy spurge is where the cancer came from. The city would not provide her with the proper safety equipment and now I am losing my mom to lung cancer. So, this crap about all the tar from smoking is just shit.