2. Smoking smarter?
"The "Natural American Spirit" cigarette, marketed here as "100% Chemical Additive-Free Tobacco." American Spirit cigarettes contain 36 percent free-base nicotine, compared with 9.6 percent in a Marlboro, 2.7 percent in a Camel, and 6.2 percent in a Winston."
Freebase nicotine - SourceWatch
"To freebase nicotine, cigarette companies add ammonia, usually in the form of diammonium phosphate. The addition of ammonia, a base, de-protonates nicotine, making it cross through membranes in the body much more easily. This makes the drug more "bioavailable" to the lungs, brain and tissues. Because ammonia is also a base (negatively charged), it strips away protons from nicotine, turning it into "freebase" form. Scientists have collected the nicotine in cigarette smoke with filters, exposed it to ammonia, and measured how different concentrations of ammonia affect the ratios of protonated to "freebase" nicotine in cigarette smoke. Studies suggest that adding ammonia has a substantial effect on the amount of freebase nicotine contained in cigarette smoke."