Original sentence: In addition, there are also similar compounds contained in cannabis that do not exhibit any psychoactive response but are obligatory for functionality: cannabidiol (CBD), an isomer of THC; cannabinol (CBN), an oxidation product of THC; cannabivarin (CBV), an analog of CBN with a different sidechain, Cannabidivarin (CBDV), an analog of CBD with a different sidechain, and cannabinolic acid.It was found in 2007 that while tobacco and cannabis smoke are quite similar, cannabis smoke contained higher amounts of ammonia, hydrogen cyanide, and nitrogen oxides, but somewhat lower levels of carcinogenic polycyclic aromatic hydrocarbons (PAHs)
Edited sentence: A 2007 report by Health Canada however, has shown that cannabis smoke contains 20 times more ammonia than tobacco (a chemical linked to cancer), and five times as much hydrogen cyanide and nitrogen oxides (linked to heart and lung damage respectively).In addition, there are also similar compounds contained in cannabis that do not exhibit any psychoactive response but are obligatory for functionality: Cannabidiol (CBD), an isomer of THC; Cannabinol (CBN), an oxidation product of THC; Cannabivarin (CBV), an analog of CBN with a different sidechain, Cannabidivarin (CBDV), an analog of CBD with a different sidechain, and Cannabinolic acid