A.Cigarettes Units Marijuana Tobacco (85mm) (85mm) Average Weight (mg) 1115 1110 Mositure (%) 10.3 11.1 Pressure Drop cm 14.7 7.2 Static Burning rate mg/s 0.88 0.80 Puff Number 10.7 11.1

B.Mainstream Smoke I. Gas Phase Units Marijuana Tobacco Carbon Monoxide % 3.99 4.58 mg 17.6 20.2 Carbon Dioxide % 8.27 9.38 mg 57.3 65.0 Ammonia mcg 228 199 HCN mcg 532 498 Cyanogen (CN)2 mcg 19 20 Isoprene mcg 83 310 Acetaldehyde mcg 1200 980 Acetone mcg 443 578 Acrolein mcg 92 85 Acetonitrilebenzene mcg 132 123 Benzene mcg 76 67 Toluene mcg 112 108 Vinyl chloride ng 5.4 12.4 Dimethylnitrosamine ng 75 84 Methylethylnitrosamine ng 27 30 pH, third puff 6.56 6.14 fifth puff 6.57 6.15 seventh puff 6.58 6.14 ninth puff 6.56 6.10 tenth puff 6.58 6.02

II. Particulate phase Units Marijuana Tobacco Tl particulate - dry mg 22.7 39.0 Phenol mcg 76.8 138.5 o-Cresol mcg 17.9 24 m- and p-Cresol mcg 54.4 65 Dimethylphenol mcg 6.8 14.4 Catechol mcg 188 328 Cannabidiol mcg 190 D9 THC mcg 820 Cannabinol mcg 400 Nicotine mcg 2850 N-Nitrosonornicotine ng 390 Naphthalene mcg 3.0 1.2 1-Methylnaphthalene mcg 6.1 3.65 2-Methylnaphthalese mcg 3.6 1.4 Benz(a)anthracene ng 75 43 Benzo(a)pyrene ng 31 21.1

"The smoke from any burning plant contains hundreds of chemicals that may have biological effects . . .""Cannabis smoke is similar to tobacco smoke in that it is a mixture of very small particles and a gas-vapor phase. Both the particulate and vapor phases contain many identified and probably some still unidentified constituents that, based on clinical experience with tobacco smoke, must be assumed to be potentially harmful. The amounts of some materials in tobacco cigarete and marijuana cigarette smoke are compared in Table 3. Toxic substances, such as carbon monoxide, hydrogen cyanide, and nitrosamines occur in similar concentrations in tobacco and marijuana smoke; so do the amounts of particulate material known collectively as "tars"." (pg 15)[Editorial comment by Jon Gettman: The cancer risk in the most part comes from the smoke, not from the cannabinoids. This is an artifact of the delivery system, not the drug (it comes from burning the plant material, not the cannabinoids). As many of you know, THC has a lower vaporization temperature than the plant material it is contained in, and as Lester Grinspoos and others often point out, a vaporizer could be designed to vaporize the cannabinoids without burning the plant material and producing smoke filled with tars and other particulate matter. Also, the composition of the plant and its smoke has been known since the 1970's, and this didn't prevent Leo Hollister and the National Academy of Sciences from noting that marijuana has therapeutic potential.]Strange Abbr: mcg: microgram C? : known Carcinogen (X means yes)Hofmann, D., Brunnemann, K.D.,Gori,G.B. and Wynder, E.L. On the carcinogenicity of marijuana smoke, pp 63-81. In Runeckles, V.C. (ed) Recent Advances in Phytochemistry New York: Plenum Publishing Corp., 1975.Hoffmann, D., Patrianakos, C., Brunneman, K.D., et al. Chromatographic determination of vinyl chloride in tobacco smoke. Anal Chem 48:47-50, 1976.Brunnemann,K.D., Lee, H.C., and Hoffmann, D. Chemical studies on tobacco smoke. XLVII. On the quantitative analysis of catechols and their reduction. Anal. Lett. 9:939-955, 1976.Brunnemann, K.D., Yu, L., and Hoffmann, D. Chemical Studies on tobacco somke. XLIX. Gas chromotographic determination of hydrogen cyanide and cynogen in tobacco smoke. J Anal. Toxicol. 1:38-42, 1977.