A concerning new study found that the aerosol from electronic cigarettes contains higher levels of measurable nanoparticle heavy metals than conventional tobacco smoke.
A new study published in the journal PLoS One has uncovered a concerning fact about electronic cigarettes (EC): toxic metal and silicate particles including nanoparticles are present in both the cigarette fluid and aerosol.1
Researchers at the Department of Cell Biology and Neuroscience, University of California Riverside, tested the hypothesis that electronic cigarettes (EC) contain metals from various components in EC. They employed a variety of testing methods to ascertain the level of contamination, including light and electron microscopy, cytotoxicity testing, and x-ray microanalysis. Their results were reported as follows:
The filament, a nickel-chromium wire, was coupled to a thicker copper wire coated with silver. The silver coating was sometimes missing. Four tin solder joints attached the wires to each other and coupled the copper/silver wire to the air tube and mouthpiece. All cartomizers had evidence of use before packaging (burn spots on the fibers and electrophoretic movement of fluid in the fibers). Fibers in two cartomizers had green deposits that contained copper. Centrifugation of the fibers produced large pellets containing tin. Tin particles and tin whiskers were identified in cartridge fluid and outer fibers. Cartomizer fluid with tin particles was cytotoxic in assays using human pulmonary fibroblasts. The aerosol contained particles >1 µm comprised of tin, silver, iron, nickel, aluminum, and silicate and nanoparticles (<100 nm) of tin, chromium and nickel. The concentrations of nine of eleven elements in EC aerosol were higher than or equal to the corresponding concentrations in conventional cigarette smoke. Many of the elements identified in EC aerosol are known to cause respiratory distress and disease.
The study authors concluded that "The presence of metal and silicate particles in cartomizer [atomizer/cartridge connecting to the battery] aerosol demonstrates the need for improved quality control in EC design and manufacture and studies on how EC aerosol impacts the health of users and bystanders."
Figure 1. Cartomizer anatomy, from the full PLoS One article. View Here
While e-cigarettes are rightly marketed as safer than conventional tobacco cigarettes, which contain thousands of known toxic compounds including highly carcinogenic radioactive isotopes, they have not been without controversy. In May 2009, the US Food and Drug Administration Division of Pharmaceutical Analysis found diethylene glycol, a poisonous liquid used in explosives and antifreeze, in one of the cartridges they sampled. They also discovered the cancer-causing agent, tobacco-specific nitrosamines, in a number of commonly used brands.2
The findings of this latest PLoS One study refutes proponents of e-cigarettes who claim that the health risks of smoking are eliminated with their use. Heavy metals like tin, aluminum, cadmium, lead and selenite are increasingly being recognized as carrying significant endocrine disrupting potential and belong to a class of metals known as 'metalloestrogens.'