Does E Liquid Contain Heavy Metals?
One of the main objections people opposed to e-cigarettes use is that the vapour produced contains “dangerous” levels of heavy metals. Professors Sebastien Soulet and Roberto Sussman have conducted an extensive review of published work and published their findings in a paper that leading electronic cigarette advocate Clive Bates calls a “must-read”. They conclude that researchers looking into this area need to “upgrade” their current lab testing standards.
Heavy metals are a group of metals that can pollute the environment and damage brain, lungs, kidney, liver, and blood. In small quantities, the same heavy metals are essential for the body to function. Typically, we are referring to aluminium, arsenic, cadmium, chromium, cobalt, copper, iron, manganese, nickel, lead, antimony, silicon, tin, and zinc.
Despite the presence of fears, Soulet and Sussman confidently state: “There is a broad consensus that vapers inhale substantially lower content of toxic and carcinogenic compounds in comparison with tobacco smoke.”
The reason for this is that the worriers are relying on research that, as Clive Bates says, “all experiments reporting levels above toxicological markers for some metals (e.g., nickel, lead, copper, manganese) exhibited…experimental flaws.”
Professors Soulet and Sussman says that electronic cigarettes are aimed at real life consumers, therefore it is important for researchers to bear in mind the limitations of laboratory testing. They raise the point that a lot of initial research (and a fair few latter-day studies) make the mistake of using puffing protocols (the number of puffs a machine takes per minute) that are far in excess of what real world vaping is like, “an increase of coil and mouthpiece temperatures that could be uncomfortable to end users”.
Vapers who have experienced a dry burn will be able to recognise the pair’s concerns over the matter. Such a condition clearly isn’t how we use our vape devices on a regular basis, and Soulet and Sussman recommend that researchers follow the manufacturer’s instructions when they design their experiments.
Going through the most often cited pieces of research that claim to have found high levels of heavy metals, Professors Soulet and Sussman discovered a mass of problems with their work.
- High Powered Sub-Ohm Devices
Researchers frequently used puffing protocols for mouth-to-lung devices yet DTL equipment needs larger airflows and puff volumes. “This testing of sub-ohm devices is unrealistic by failing to achieve even a minimal approximation to the real life usage of the devices,” they said.
- Pod Devices
The only papers reporting elevated readings clearly came from “a defective cartridge subjected to leaching or corrosion that could have been repellent to users”.
- Testing Old Devices: Corrosion
“Some of the studies tested devices that were acquired years before their laboratory testing,” they write. The results are therefore “irrelevant for most users typically consuming these products within the next few days after their purchase.”
- Comparison with Toxicological References
Here they identified flaws in simple maths and a lack of understanding of how volumes dilute. The level of errors here make it incredible the research papers were ever allowed to be published.
- Information Vacuum
A further flaw several researchers presented with was that they simply failed to document their devices, puffing protocols and outcomes which is a basic school-level fail.
- Aerosol Collection
Without a standardised collection method of the ecig vapour, contamination can occur from any number of sources – “It is possible that some of the reviewed studies might have reported overestimations of metal outcomes from contamination from aerosol collection methods and materials”.
Ultimately, Professors Sebastien Soulet and Roberto Sussman concluded that none of the papers they looked at held up to scrutiny and none of the claims of vapour containing heavy metals are supportable. They hope their recommendations will be taken into consideration in future pieces of work.