The case of an e-cigarette user with a rare form of lung scarring typically found in metal workers has prompted more warnings about the dangers of vaping.
A report in the European Respiratory Journal said that an e-cigarette user in California was diagnosed with a condition known as hard-metal pneumoconiosis despite having had no known exposure to working with hard metals such as cobalt or tungsten.
The condition causes a distinctive pattern of scarring and damage to the lung tissues. The case represents the first known example linked to vaping.
Professor Kirk Jones, from the University of California, San Francisco, said: “This patient did not have any known exposure to hard metal, so we identified the use of an e-cigarette as a possible cause.”
When researchers tested the patient’s e-cigarette, which was used with cannabis oil, they found cobalt in the vapour it released, as well as other toxic metals: nickel, aluminium, manganese, lead and chromium.
It is thought the metals come from the heating coils found in vaping devices.
Dr Rupal Shah, part of the research team, said: “This is the first known case of a metal-induced toxicity in the lung that has followed from vaping and it has resulted in long-term, probably permanent, scarring of the patient’s lungs.
“We think that only a rare subset of people exposed to cobalt will have this reaction, but the problem is that the inflammation caused by hard metal would not be apparent to people using e-cigarettes until the scarring has become irreversible, as it did with this patient.”
However, other scientists say that, while cannabis oils should be avoided, vaping is still a better alternative to traditional smoking.
Professor John Britton, director of the UK Centre for Tobacco & Alcohol Studies and consultant in respiratory medicine at the University of Nottingham, suggested that the conclusions were not all they seemed.
He said there was no evidence of any cobalt particles in the lung samples and that claims made about vaping were wrong.
He added: “There is nothing in this new paper that should change advice to smokers. If you smoke, switch. If you don’t smoke, don’t vape. And just as you wouldn’t buy unlicensed alcoholic drinks, don’t vape cannabis or other bootleg products.”
Dr Nick Hopkinson, medical director at the British Lung Foundation, said this latest case linked to vaping cannabis oil was another reason to avoid it.
He said: “The higher temperature involved in vaping cannabis oil compared to normal products may increase the risk that metal from the heating element is inhaled.
“People who are vaping in the UK should only use products regulated by the MHRA. Although vaping is much safer than smoking cigarettes, people who do vape should try to quit that too in the long term – but not at the expense of going back to smoking.”