>As I understand there have been some studies that disprove this assertion. May I ask where you get your numbers from please or are you just repeating a sort of urban legend.

The actual estimated figures given were reported by the Environmental Protection Agency : 3800 deaths due to lung cancer, 46000 deaths due to other causes - so just short of 50000. No reference was given to an actual report, but the book was published in 1991.

A report from 1995, gives the following estimates : 3200 deaths due to lung cancer, 12000 deaths due to other cancers & 37000 deaths due to heart disease - so around 52000 deaths per year in the US.
http://www.lipidforum.at/Wissenschaft/Experten/kritz1.htm

Your National Institute on Drug Abuse give the following figures for 1992 : 132000 deaths from drug abuse, broken down as 107000 deaths from alcohol abuse & 25000 from other drug abuse. So alcohol claims 4 times as many lives as other drugs.
http://165.112.78.61/EconomicCosts/Chapter5.html

One estimate of deaths due to smoking in the US (other than passive smoking) is around 300000 (from same EPA report above, I believe). So (in round figures) there are around 500000 deaths in the US each year due to some form of drug abuse, 95% due to legal drugs & 5% due to illegal drugs. So maybe it is reasonable to review the legality of some (maybe all) currently illegal drugs.