Cannabis smoking (known colloquially as smoking weed or smoking pot) is the inhalation of smoke or vapor released by heating the flowers, leaves, or extracts of cannabis and releasing the main psychoactive chemical, Δ9-tetrahydrocannabinol (THC), which is absorbed into the bloodstream via the lungs. Archaeological evidence indicates cannabis with high levels of THC was being smoked at least 2,500 years ago. In addition to being smoked and vaporized, cannabis and its active cannabinoids may be ingested, placed under the tongue, or applied to the skin. The bioavailability characteristics and effects of smoking and vaporizing cannabis differ from other cannabis consumption methods in having a more rapid and predictable onset of effect. Methods Cannabis (marijuana) can be smoked in a variety of pipe-like implements made in different shapes and of different materials including hand pipes ("bowls"), water pipes ("bongs"), cigarettes ("joints"), or blunts. Solar puffing (also called solar toking, taking solar hits”, or “solar bowls” ) is the act of using the sun's rays with a magnifying lens or burning glass to heat cannabis for consumption. Hotboxing involves multiple persons smoking cannabis in an enclosed space, such as a car, with no way for smoke to escape. In addition to the primary smoke from the chosen smoking devices, second hand smoke is repeatedly inhaled and exhaled. A single user breathing in and out of a breathbonnet (breadbag) can achieve this effect. Vaporization Vaporizers (vape pens and/or stationary platform) are devices used to extract the active ingredients of cannabis, tobacco (E-cigarettes), or any plant material at lower than burning temperature, eliminating carbon monoxide and carcinogenic "tars" found hazardous in smoke. 197 °C / 385 °F is frequently mentioned as a good vaporizing temperature for favored cannabinoids. Utensils usually thought of as smoking pipes can be used to vaporize if the receptacle, or "bowl", is narrow enough to permit controlling the inward flow of heated air from a source such as a lighter which is held far enough below the opening. According to the journal Clinical Pharmacology & Therapeutics, vaporizing cannabis is a safe and more effective way (than smoking) of delivering THC to patients for medical uses. The feasibility of vaporization of THC has been demonstrated in a series of laboratory studies involving different vaporizer designs. An electric vaporizer was shown to release substantial amounts of the THC while producing no measurable amounts of benzene, toluene, and naphthalene, which are generated when