The UK should rethink restrictions on nicotine levels in e-cigarettes, researchers argue, saying people using lower nicotine concentration e-liquids take longer and more frequent puffs, increasing their exposure to potentially harmful compounds.
Addressing a parliamentary inquiry into e-cigarettes last week, smoking cessation expert Dr Lynne Dawkins said there was no evidence for increased harms of nicotine at levels above the current cap of 20 mg/ml.
“[The cap] seems arbitrary to me,” said Dr Dawkins, an associate professor at the Centre for Addictive Behaviours Research at London South Bank University.
However, lower concentration nicotine e-liquids may more harmful than higher concentrations, with research from her group suggesting people compensated for the reduced nicotine by increasing puff duration and frequency.
“… [T]hat is costly financially, as you are using more e-liquid, and it may also come with a health cost if increased exposure [to carbonyl compounds] translates to long-term health risk,” she told the inquiry.
In a written submission, Dr Dawkins and colleagues explained more intensive puffing patterns can lead to the atomiser coil in the e-cigarette overheating, resulting in increased carcinogen production.
In their latest study of 20 vapers using high vs low nicotine concentrations (manuscript under review), they found urinary levels of formate – a metabolite of formaldehyde – were significantly higher when people used a low concentration e-liquid with a higher power setting.