Articles published between January 2012 and October 2020 were considered if it had information regarding marijuana toxicity and medicinal properties. Further searches were conducted in google search engine by including general terms such as; marijuana toxicity, cancer, carcinogenicity, dangers, intake methods, throat cancer, smoking, cigarettes and cessation. Where there was need, the search outputs were saved in databases and the authors received notifications for searches that met the search criteria from science direct, PubMed, cross-ref and google scholar.There exists three major cannabis delivery techniques including inhalation, oral and topical, that have been frequently applied for use in different occasions with each method having various designed techniques that offer unique functions and results.Smoking and vaporization are the most prevalent ancient customary inhalation methods that are commonly used and involves the use of hand pipes, water pipes, paper rolls , hooker and shisha.

On the other hand, vaporization technique encompass the usage of vaporizers that steadily heat up cannabis herbs to temperatures high enough to extract THC, CBD and other cannabinoids but too low to expedite the release of harmful toxins such as benzene and toluene as well as odor,which are emitted thereby presumably, lowering the associated health risks throughout the marijuana smoking duration .This technique is widely used and differs from the traditional smoking habit,given that it does not involve combustion. For this reason therefore, vaporization method can be considered safer because it minimizes exposure to the potentially harmful marijuana smoke effluents that could be carcinogenic and toxic to the health of both active and passive smokers . Vaporized cannabis includes the use of vape pens, dab rigs and desktop vaporizers such as volcano medic vaporizer. In comparison, vaporized and smoked THC have similar pharmacokinetic profiles but on the contrary, vaporizers produce higher THC concentrations compared to smoked cannabis resulting to greater THC concentrations in blood, drug effects, mouth dryness and dry irritated eyes when same doses are smoked and vaped.For instance,marijuana edibles include drinks, foods and lozenges which have been infused with THC while tinctures include liquid cannabis extracts consumed by placing 3 – 4 drops under the tongue and gets immediately absorbed into the body system.

Consequently, marijuana products are classified as liquids , soft solids , and hard solids .A range of marijuana ingestion methods and their popularity is reported in Table 1. A good number of scientific researches have extensively identified the chemical composition of marijuana smoke and evidently noted that there exists a close association in chemical composition between second hand marijuana smoke,and tobacco smoke. The outstanding differences lies in the component concentrations variation with remarkably similar chemicals such as nitric oxides and aldehydes which have been proven to cause detrimental health effects .There is substantially little scientific research that has explored the chemical characterization of marijuana cigarette smoke but most of the available studies have focused on determining cannabinoids in marijuana smoke and reported it to contain most toxins, irritants and carcinogens commonly present in tobacco smoke . For instance, when smoked, marijuana releases more tar accompanied by substantially higher concentrations of carcinogens such as benzopyreneas compared to tobacco smoke, and consequently it has been classified as a secondary carcinogen that possesses approximately 50% to 70% more carcinogenic polycyclic aromatic hydrocarbons such as benzoanthracene, benzene and phenols in alongside toxic gases and reactive oxygen species that are 20 times higher in concentration than they are in tobacco .

Notably, these variations in carcinogenic compound concentration in marijuana enhance its probability of causing lung cancer in the same way tobacco does, which has been credited as the leading cause of lung cancer in various researches. Nevertheless,it can be presumed that smoking of marijuana is a precursor for respiratory disease and cancer similar to those caused by tobacco smoking, but on the other hand, there is minimal literature demonstrating that marijuana smoking causes cancer. Additionally, it has been suggested that marijuana smoke comprises of particulate matter that is harmful and carcinogenic when inhaled because it contains potent compounds such as volatile organics and aromatic amines .A range of toxic molecular compounds isolated from marijuana and their classification are presented in Table 2. Marijuana smokers are motivated by its psychotropic effects characterized by a pleasurable feeling, euphoria and relaxation which result in psychotic symptoms,cognitive changes, panic reactions and anxiety which have been reported as severe side effects .