Cigarettes, Cigars, Marijuana, and Vaping

Tobacco products are found to contain lead, cadmium, nickel, chromium, arsenic, and mercury. Different products and different brands have varying concentrations of each.

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LEVELS OF HEAVY METALS IN POPULAR CIGARETTE BRANDS AND EXPOSURE TO THESE METALS VIA SMOKING

This study confirms that tobacco is a notable source of many heavy metal pollutants particularly Cd and Pb. The amount of Cd inhaled from smoking one pack of 20 cigarettes of different cigarette brands is estimated to be 1.40–2.70 μg. This value is comparable with the values from UK cigarettes (1.32–2.64 μg) and Korean cigarettes (1.54–3.08 μg). The small variation could be possibly attributed to Cd soil content, type of tobacco, growth conditions, and tobacco treatment process. The amount of Pb inhaled from smoking one pack of 20 cigarettes of the brands studied is estimated to be 1.98–3.37 μg, and this value is nearly 4 times higher compared with the UK cigarettes (0.22–0.65 μg) and 3.5 times that of Korean cigarettes (0.4–1.19 μg). Smoking of 20 cigarettes per day has been estimated to result in the inhalation of 2–4 μg Cd and 1–5 μg Pb, or even more.

Ashraf, Muhammad Waqar. “Levels of heavy metals in popular cigarette brands and exposure to these metals via smoking.” TheScientificWorldJournal vol. 2012 (2012): 729430. doi:10.1100/2012/729430

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REVIEW OF CIGARS AND CIGAR-TYPE PRODUCTS AS POTENTIAL SOURCES OF CONSUMER EXPOSURE TO HEAVY METALS

Among the heavy metals, the following contents of elements in tobacco were recorded in cigars: Fe (420–2200 µg/g), Mn (100–370 µg/g), Zn (14–180 µg/g), Cu (15–140 µg/g), Pb (not detected–32 µg/g), Cd (nd–19 µg/g), Ni (nd–13 µg/g), Cr (nd–10 µg/g), Co (0.65–1.0 µg/g), As (nd–0.66 µg/g), Hg (18–25 ng/g). Importantly, the values often differ between cigars of different origins and types, indicating the need for more extensive research.

Hać, Paweł Jacek et al. “Review of cigars and cigar-type products as potential sources of consumer exposure to heavy metals.” Journal of environmental science and health. Part C, Toxicology and carcinogenesis vol. 40,2 (2022): 172-196. doi:10.1080/26896583.2022.2052708

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TOXIC METAL CONCENTRATIONS IN CIGARETTES OBTAINED FROM U.S. SMOKERS IN 2009: RESULTS FROM THE INTERNATIONAL TOBACCO CONTROL (ITC) UNITED STATES SURVEY COHORT
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Cigarettes obtained from a sample of smokers in the United States were found to contain metals that could potentially be harmful to human health. The average metal concentrations observed per gram of unburned tobacco were comparable to amounts found in cigarettes on the US, Canadian, and Brazilian markets, but less than those found in cigarettes purchased in China.

Caruso, Rosalie V et al. “Toxic metal concentrations in cigarettes obtained from U.S. smokers in 2009: results from the International Tobacco Control (ITC) United States survey cohort.” International journal of environmental research and public health vol. 11,1 202-17. 20 Dec. 2013, doi:10.3390/ijerph110100202

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METAL CONCENTRATIONS IN E-CIGARETTE LIQUID AND AEROSOL SAMPLES: THE CONTRIBUTION OF METALLIC COILS

Our findings indicate that e-cigarettes are a potential source of exposure to toxic metals (Cr, Ni, and Pb), and to metals that are toxic when inhaled (Mn and Zn). Markedly higher concentrations in the aerosol and tank samples versus the dispenser demonstrate that coil contact induced e-liquid contamination.

Olmedo, Pablo et al. “Metal Concentrations in e-Cigarette Liquid and Aerosol Samples: The Contribution of Metallic Coils.” Environmental health perspectives vol. 126,2 027010. 21 Feb. 2018, doi:10.1289/EHP2175

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UNTESTED, UNSAFE? CANNABIS USERS SHOW HIGHER LEAD AND CADMIUM LEVELS

Cannabis belongs to a class of plants known as hyperaccumulators because their tissues can accumulate metals from soil, water, fertilizers, and other sources at levels hundreds or thousands of times greater than is normal for most plants.

Researchers with Columbia University reviewed data from the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018 representing 7,254 participants who completed a drug use questionnaire and provided single samples of blood and urine. In their analysis, the researchers adjusted for factors that may affect exposure to metals and their excretion. These included race/ethnicity, age, sex, education, tobacco use, and seafood consumption.
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They found that survey participants who reported using marijuana but no tobacco in the previous 30 days had higher levels of cadmium and lead in their blood and urine than did those who had used neither marijuana nor tobacco. Users had cadmium levels on average 22% higher in blood and 18% higher in urine than nonusers. Lead levels were higher by 27% in blood and 21% in urine. None of the 15 other elements evaluated—including arsenic, cobalt, manganese, mercury, and uranium—showed a clear association with cannabis use.

Seltenrich, Nate. “Untested, Unsafe? Cannabis Users Show Higher Lead and Cadmium Levels.” Environmental health perspectives vol. 131,9 (2023): 94001. doi:10.1289/EHP13519

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METAL/METALLOID LEVELS IN ELECTRONIC CIGARETTE LIQUIDS, AEROSOLS, AND HUMAN BIOSAMPLES: A SYSTEMATIC REVIEW

Numerous metals/metalloids—Al, Sb, As, Cd, Co, Cr, Cu, Fe, Pb, Mn, Ni, Se, Sn, and Zn—were present in e-cigarette samples in the studies reviewed. For most metals/metalloids, levels were heterogeneous according to sample (e-liquid, aerosol), source of the sample (bottle, cartridge, open wick tank), and device type (cig-a-likes and tank). Studies of biosamples support the hypothesis that e-cigarettes are a source of metals/metalloids because most metal/metalloid biosample levels, with the exception of Cd, were similar or even higher in e-cigarette users in comparison with conventional cigarette users, and higher in comparison with cigar users. The direct comparison of metal/metalloid aerosol levels to human biosample levels also provides direct support for the hypothesis that aerosol metals/metalloids are inhaled and absorbed by the e-cigarette user.
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In comparison with conventional cigarettes, e-cigarette aerosols may result in less exposure to Cd but not to other toxic metals/metalloids found in tobacco. 

Zhao, Di et al. “Metal/Metalloid Levels in Electronic Cigarette Liquids, Aerosols, and Human Biosamples: A Systematic Review.” Environmental health perspectives vol. 128,3 (2020): 36001. doi:10.1289/EHP5686