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.”
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.’
One of the unintended, adverse consequences of nanotechnology in general is that by making a substance substantially smaller in size than would occur naturally, or though pre-nanotech production processes, the substance may exhibit significantly higher toxicity when in nanoparticle form. Contrary to older toxicological risk models, less is more: by reducing a particle’s size the technology has now made that substance capable of evading the body’s natural defenses more easily, i.e. passing through pores in the skin or mucous membranes, evading immune and detoxification mechanisms that evolved millions of years before the nanotech era.
For example, when nickel particles are reduced in size to the nanometer range (one billionth of a meter wide) they may actually become more toxic to the endocrine system as now they are capable of direct molecular interaction with estrogen receptors in the body, disrupting their normal structure and function.3 4 5 Moreover, breathing these particles into the lungs, along with other metals, ethylene glycol and nicotine produces a chemical concoction exhibiting synergistic toxicity, i.e. the toxicity of the whole is higher than the sum of their parts. These sorts of “chemical soups” are exceedingly difficult to study, as they embody a complexity that analytical and theoretical models within toxicology are not equipped to readily handle. Nonetheless, it is likely that when taken together the harms done by e-cigarettes are significant, and will likely manifest only after chronic use when identifying ‘singular causes’ of disease is nearly impossible. Regulators will have a hard time, therefore, identifying a “smoking” gun even after a broad range of health issues do emerge in exposed populations.
Ultimately, finding a less harmful alternative to tobacco smoking is justified, but let buyer (and user) beware, the products are not without possible harm as some marketers falsely advertise.