Marijuana is one of the most widely-used drugs around the world. Used by all demographics, its popularity is rising. According to a 2020 statistic, in the United Kingdom, 31.2% of the population of England and Wales between the ages of 16 and 59 had used cannabis at least once during their lifetime, up from 28.9% in 2001. Furthermore, 7.1% of the population in the UK had used it within the last year¹. With its strong odour and negative health effects due to second-hand smoke, cannabis is often a nuisance to roommates and neighbours. What are the dangers of second-hand cannabis smoke? How can an air purifier for cannabis help? Read on to learn more.

Second-hand cannabis smoke

A significant portion of young people believe that second-hand cannabis smoke (also known as SHCS) is less dangerous than tobacco smoke. In fact, 27% of young adults surveyed believe SHCS to be safe, according to UC Berkeley Public Health².

Which pollutants/chemicals are found in cannabis smoke?

According to one of the first studies of its kind, a paper published in 2022 analysed the effects of cannabis use using a bong in the home. The results found SHCS to be more toxic than that of tobacco smoke. It contains several hundred chemicals, many of which are carcinogenic³. This poses serious health danger to both first-hand marijuana smoke and second-hand smokers. Specifically, the following air pollutants were analysed:

Particulate matter

Levels of fine particle pollution, also known as particulate matter (PM), were extremely high. PM2.5 concentrations were 10 times greater in weed smoke than the levels measured during ‘orange sky days’ caused by wildfires and Sahara desert dust. Furthermore, particles released by marijuana smoke remain in the air for much longer than PM emitted by tobacco smoke: 12 hours after cannabis smoking had ceased, PM levels still exceeded the World Health Organization (WHO)’s recommendations³.

Typical PM levels in the home are as follows:

• Non-smoking homes: 15 μg/m3
• Cigarette-smoking homes: 44 μg/m3
• Cannabis-smoking homes: 200 μg/m3
• WHO recommendations: 10 μg/m3 for PM2.5, 20 μg/m3 for PM10

Volatile organic compounds (VOCs)

A 2015 study compared urinary levels of VOCs and PAHs in cannabis smokers versus non-smokers. It found a significantly higher level of toxic byproducts of combustion (VOCs and PAHs specifically) in cannabis smokers compared to non-smokers⁴.

Some of the most common VOCs found in cigarette and cannabis smoke include formaldehyde, benzene, toluene, styrene, nitrogen oxides, xylenes, and ethylbenzene. Carbon monoxide is also found in cigarette smoke. In 2012, a list was published by the Food and Drug Administration (FDA) containing ‘harmful and potentially harmful constituents’ (HPHCs) found in cigarettes. The list includes 93 substances, 33 of which are VOCs⁵. The level of terpenes, natural compounds found in cannabis that give it its distinct marijuana odour when smoked, is one of the factors that determines the severity of exposure to HPHCs⁶.

Heavy metals and toxic gases

Marijuana smoke contains a variety of heavy metals. Cadmium, mercury, nickel, chromium, and lead are all found in cannabis smoke. Ammonia, hydrogen cyanide, nitrogen oxides, and other aromatic amines are all found in levels three to five times higher in marijuana smoke than cigarette smoke⁷.

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Is cannabis smoke bad for your health?

Cannabis smoke is a throat and lung irritant. Certain aspects of smoking marijuana put the smoker and secondary-smoker at higher risk than a tobacco smoker. For example, marijuana joints are typically less tightly packed, meaning that more smoke particles and tar are inhaled. Marijuana smokers, on average, inhale more deeply and retain the smoke inside their longs for a longer period of time than a cigarette smoker. This longer exposure time amplifies the negative effects on health that the toxic substances found in cannabis smoke have on the body. This ultimately contributes to the increased risk of the following health effects.

‘Contact high’

Under extreme, short-term conditions with little ventilation, a second-hand cannabis smoker may experience the same effects as a first-hand smoker. This may include low to moderate sedative effects, minor cognitive impairment, and difficulties concentrating⁸. This is referred to as a ‘contact high’ and may cause a person who did not directly smoke marijuana to fail a drug test.

Cancer risk

A person who experiences exposure to marijuana smoke is at risk of the same adverse health effects as second-hand tobacco smoke. The biggest risk is multiple types of cancer, especially lung cancer. A 2008 study found that the risk of lung cancer increases by 8% every year that a person smokes a joint on a daily basis⁹. The California Environmental Protection Agency has identified ‘at least 33 constituents present in both marijuana smoke and tobacco smoke’ as carcinogenic¹⁰.

Effects on immune, endocrine, cardiovascular, and respiratory systems

As with cigarette smokers, a heavy cough and chronic bronchitis are common amongst heavy marijuana users. Weed smoke is genotoxic and has negative effects on the immune, endocrine, and cardiovascular systems. A study on rats performed in 2016 found that second-hand cannabis smoke impacts blood vessels and endothelial function to an equivalent extent as tobacco smoke. However, it has an even longer-lasting effect¹¹.

Since marijuana, specifically THC (tetrahydrocannabinol, the principal psychoactive component in cannabis), is immunosuppressive, smokers may be at higher risk of lung infections in those who are immunodeficient. It may also reduce the immune response in the respiratory system and increase the likelihood of acquiring a respiratory infection. Smoking marijuana is associated with inflammation of the large airway, increased airway resistance, and hyperinflation of the lungs¹².

Minimise your exposure to the chemicals in marijuana smoke

A few tips to reduce your and your loved ones’ exposure to the harmful substances and chemicals in cannabis smoke are:

• Smoke only in places that are well-ventilated: ideally outdoors, by a window, or near a fan
• Reduce your paper usage to produce less smoke
• Clean your home regularly to avoid the build-up of third-hand smoke and residue on your furniture and carpets
• Convert to other cannabis consumption methods like edibles or vaporisation

The benefits of an air purifier for cannabis or weed

The main goal of investing in an air purifier for cannabis or weed smoke is to eliminate its smell/odours in your home and protect your health. An air purifier that is equipped with the proper air purification technology (or technologies) like activated carbon filters removes unpleasant marijuana odours that enter your home. If you are exposed to weed smoke that enters your room or your home from your neighbours who smoke it, protect your own health and well-being and that of your loved ones with an air purifier.

Reducing cannabis smoke in residential settings can not only improve indoor air quality, but it can also improve productivity. Studies have shown that in addition to all of its negative health effects, poor indoor air quality (IAQ) leads to reduced focus and concentration.

How to choose an air purifier for cannabis or weed smoke?

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If you are a cannabis smoker yourself or are exposed to cannabis smoke by family members, roommates, or neighbours, an air purifier for cannabis or weed may be exactly what you need to protect your health. But how do you choose the right device? Consider the following when making your choice.

Choose the right filter

Not all filters will combat the fine particle pollution (particulate matter) emitted by weed smoke. Be sure that your filter contains a HEPA (high-efficiency particulate air) filter which guarantees the removal of 99.97% of particles down to a size of 0.01 microns. HEPA filters do not remove harmful volatile organic compounds (VOCs) or odours from marijuana smoke, however! Your device should also contain an activated carbon filter and photocatalysis technology in order to remove both VOCs and odours found in cannabis or weed smoke from your breathing air. Activated carbon filters are one of the oldest forms of air and water filtration, and they are extremely effective at removing unpleasant smells from marijuana and VOCs.

• Even better: find a device that removes all types of air pollution. Eoleaf’s air purifiers use a proprietary 8-step technology (including both a HEPA filter and an activated carbon filter) that combats all kinds of air pollutants!
• Keep in mind that ‘HEPA-type’ filters are not guaranteed to perform the same level or quality of filtration as HEPA-certified filters are.

Consider the size of your space

Air purifiers are made to filter the air in spaces of a maximum size. If you are looking to install a device in a room in your home, be sure that you choose a device that is properly sized for optimal filtration. The devices in Eoleaf’s product range are sized as follows:

• AEROPRO 40: for rooms from 0 to 40 m² (450 ft²)
• AEROPRO 100: for rooms from 0 to 80 m² (850 ft²)
• AEROPRO 150: for rooms from 0 to 120 m² (1300 ft²)

Air purifiers are particularly useful for commercial cannabis cultivation facilities. The UK is the world’s largest exporter of legal marijuana, meaning that there are many employees working in this industry that may benefit from safer air in these facilities. Employees in the cannabis grower’s industry may be exposed to pesticides, insecticides, elevated levels of carbon dioxide (used to encourage plant growth), and even mould and spores from the high humidity environments required for large-scale plant growth.

Ensure proper placement

If you are a cannabis smoker yourself, consider the rooms in which you smoke most. Do you commonly smoke in your bedroom or living room? These are the rooms where installing an air purifier for cannabis smoke and odours would be ideal to fight against both cannabis odour/smell and its harmful effects. If you are a non-smoker but are exposed to marijuana smoke, place your air purifier as close to the points of entry as possible. Be sure that your device is unimpeded by furniture, walls, or other obstacles.

For more questions on combatting first- or second-hand marijuana smoke or other indoor air pollutants in your home, don’t hesitate to reach out to our team of air purification experts. We are here to help you find the perfect device for your situation. We also encourage you to refer to our in-depth Buying Guide that helps you consider all of the factors that need considering before purchasing an air purifier.

References

¹ Clark, D. (2023, February 28). Cannabis use in England and Wales 2021. Statista. https://www.statista.com/statistics/976850/cannabis-use-in-the-uk/

² Proulx, E. (2022, April 1). First-of-its-kind research shows dangers of secondhand cannabis smoke. UC Berkeley Public Health. https://publichealth.berkeley.edu/news-media/research-highlights/first-of-its-kind-research-shows-dangers-of-secondhand-cannabis-smoke/

³ Nguyen PK, Hammond SK. Fine Particulate Matter Exposure From Secondhand Cannabis Bong Smoking. JAMA Netw Open. 2022;5(3):e224744. doi:10.1001/jamanetworkopen.2022.4744

⁴ Wei B, Alwis KU, Li Z, Wang L, Valentin-Blasini L, Sosnoff CS, Xia Y, Conway KP, Blount BC. Urinary concentrations of PAH and VOC metabolites in marijuana users. Environ Int. 2016 Mar;88:1-8. doi: 10.1016/j.envint.2015.12.003. Epub 2015 Dec 12. PMID: 26690539; PMCID: PMC5024567.

⁵ Pazo DY, Moliere F, Sampson MM, Reese CM, Agnew-Heard KA, Walters MJ, Holman MR, Blount BC, Watson CH, Chambers DM. Mainstream Smoke Levels of Volatile Organic Compounds in 50 U.S. Domestic Cigarette Brands Smoked With the ISO and Canadian Intense Protocols. Nicotine Tob Res. 2016 Sep;18(9):1886-94. doi: 10.1093/ntr/ntw118. Epub 2016 Apr 25. PMID: 27113015; PMCID: PMC5687062.

⁶ Meehan-Atrash J, Luo W, McWhirter KJ, Dennis DG, Sarlah D, Jensen RP, Afreh I, Jiang J, Barsanti KC, Ortiz A, Strongin RM. The influence of terpenes on the release of volatile organic compounds and active ingredients to cannabis vaping aerosols. RSC Adv. 2021 Mar 23;11(19):11714-11723. doi: 10.1039/d1ra00934f. PMID: 35423635; PMCID: PMC8695911.

⁷ Moir D, Rickert WS, Levasseur G, Larose Y, Maertens R, White P, Desjardins S. A comparison of mainstream and sidestream marijuana and tobacco cigarette smoke produced under two machine smoking conditions. Chem Res Toxicol. 2008 Feb;21(2):494-502. doi: 10.1021/tx700275p. Epub 2007 Dec 7. PMID: 18062674.

⁸ Herrmann ES, Cone EJ, Mitchell JM, Bigelow GE, LoDico C, Flegel R, Vandrey R. Non-smoker exposure to secondhand cannabis smoke II: Effect of room ventilation on the physiological, subjective, and behavioral/cognitive effects. Drug Alcohol Depend. 2015 Jun 1;151:194-202. doi: 10.1016/j.drugalcdep.2015.03.019. Epub 2015 Apr 6. PMID: 25957157; PMCID: PMC4747424.

⁹ Aldington S, Harwood M, Cox B, Weatherall M, Beckert L, Hansell A, Pritchard A, Robinson G, Beasley R; Cannabis and Respiratory Disease Research Group. Cannabis use and risk of lung cancer: a case-control study. Eur Respir J. 2008 Feb;31(2):280-6. doi: 10.1183/09031936.00065707. PMID: 18238947; PMCID: PMC2516340.

¹⁰ Tomar, R. S., Beaumont, J., & Hsieh, J. C. (2009, August). Evidence on the carcinogenicity of marijuana smoke. Reproductive and Cancer Hazard Assessment Branch Office of Environmental Health Hazard Assessment. https://oehha.ca.gov/media/downloads/proposition-65/chemicals/finalmjsmokehid.pdf

¹¹ Wang X, Derakhshandeh R, Liu J, Narayan S, Nabavizadeh P, Le S, Danforth OM, Pinnamaneni K, Rodriguez HJ, Luu E, Sievers RE, Schick SF, Glantz SA, Springer ML. One Minute of Marijuana Secondhand Smoke Exposure Substantially Impairs Vascular Endothelial Function. J Am Heart Assoc. 2016 Jul 27;5(8):e003858. doi: 10.1161/JAHA.116.003858. PMID: 27464788; PMCID: PMC5015303.

¹² NIDA. 2023, July 28. What are marijuana's effects on lung health?. Retrieved from https://nida.nih.gov/publications/research-reports/marijuana/what-are-marijuanas-effects-lung-health on 2023, October 25