A million times more harmful than outdoor air: Hong Kong study raises e-cigarette cancer alarm

Electronic cigarettes were found to contain one million times more cancer-causing substances than outdoor air in a study by Baptist University.

Researchers also discovered a type of flame retardant that affected the reproductive system and could lead to cancer – the first such discovery in e-cigarettes.

The Hong Kong Council on Smoking and Health, which commissioned the study, called for a ban on e-cigarettes as soon as possible before they become more popular.

In analysing 13 types of e-cigarettes bought on the market, researchers found that the level of polycyclic aromatic hydrocarbons (PAHs) – a by-product of burning petroleum that is commonly detected in roadside air – ranged from 2.9 to 504.5 nanograms per millilitre.

The substance, which contains highly carcinogenic chemicals such as benzo(a)pryene, also carries various kinds of chemicals that promote growth of cancer cells.

“[Level of PAHs] in e-cigarettes is at least one million times more than roadside air in Hong Kong,” said Dr Chung Shan-shan, assistant professor in the university’s biology department.

Polybrominated diphenyl ethers(PBDEs), a flame retardant used extensively in furniture and electronic products, were detected in a range of 1.7 to 1,490ng/ml in the 13 brands of e-cigarettes.