E-Cigarettes As A Source Of Exposure To Toxic And Carcinogenic Metals

Abstract

Aims: To quantify the concentration of toxic metals in seven commercially available brands of e-cigarette liquid and to compare the metals found in e-cigarette liquid to metals found in traditional cigarettes. Background: The popularity of electronic cigarette devices is growing worldwide. The health impact of e-cigarette use, however, remains unclear. The commonly held belief regarding e-cigarettes is that they are a safe alternative to cigarettes. Traditional cigarettes contain high amounts of toxic and carcinogenic metals, namely cadmium and lead. Methods: We analyzed the liquid in 7 commercially popular brands of e-cigarettes, based on retail availability in Baltimore, MD. Liquid from 10 cartridges from each brand were extracted by centrifuging liquid-containing pads and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Results: All of the tested metals (antimony, beryllium, cadmium, chromium, lead, manganese and nickel) were found in the e-liquids analyzed. Across all analyzed brands, mean (SD) concentrations ranged from 0.29 (0.40) to 1968 (1541) μg/L for lead, 3.2 (1.4) to 2118 (5223) μg/L for chromium and 1.01 (0.27) to 22650 (24423) μg/L for nickel. Nickel and chromium are known inhalation carcinogens and levels in some brands exceeded those reported in traditional cigarettes. Antimony, beryllium and manganese are also toxic and concentrations ranged from 1.7 (1) to 738 (484) μg/L, 0.56 (0.65) to 1.6 (1.6) μg/L, and 0.21 (0.15) to 6919 (12297) μg/L, respectively. The brand with the highest cadmium concentrations ranged from 0.26 (0.04) to 0.53 (0.4) μg/device compared to reported concentrations found in cigarettes from 0.04 to 0.6 μg Cd/cigarette. As expected there is high variability between brands and high variability (up to 250%) within brands. Conclusions: E-cigarettes may be an exposure pathway for toxic metals in users. While potentially similar in cadmium as tobacco, some brands contain high levels of other carcinogenic metals.