The controversy surrounding e-cigarettes is gaining momentum. Surprisingly, this time it’s not about nicotine. Additives are now attracting medical attention. The liquids, ie. evaporation solvents, consist of propylene glycol (food additive E 1520), glycerine (food additive E422) and water. In their quest to draw young users, manufacturers are forking out barrow-loads of options. They’re bringing “sweet” flavour trends such as “cotton candy”, “fruitsquirt”, “popcorn”, “cupcake”, “nougat” and “eggnog” into the range of sales. With around 7,000 different flavour options existing one is scarcely able to keep up with the extent of this range.
Molecules with eccentricities
Joseph G. Allen, a researcher at the Harvard TH Chan School of Public Health in Boston, has put its components under the microscope. For his study Allen acquired 51 e-cigarettes from leading US manufacturers. Allen simulated the situation which occurs during consumption by using air flow and a closed chamber. The focus of his work was carbonyl compounds such as diacetyl, acetoin and 2,3-pentanedione. At least one of these controversial molecules was able to be detected in any of 47 products. Diacetyl appeared in 39 samples; the maximum amount was 239 micrograms per cigarette. The researchers found 2,3-pentanedione and acetoin in 23 and 46 of the electric “glowsticks” respectively. Here, the maximum levels were 64 and 529 micrograms per cigarette. “Based on the association between diacetyl, bronchiolitis obliterans and other severe respiratory diseases among workers, the urgent recommendation was made to assess this potentially widespread exposure to flavoured e-cigarettes”, says Joseph G. Allen. A year earlier Konstantinos E. Farsalinos, a doctor at Greece’s Onassis Cardiac Surgery Center, Kallithea, published similar figures. He spoke about the possibility of eliminating diacetyl, without affecting flavour. Manufacturers apparently have not taken his advice. The bill is being paid by consumers, as the earliest publications indicate.
Graham Atkins and Frank Drescher from Dartmouth-Hitchcock Medical Center in Lebanon (in New Hampshire, the US state) report an unusual case. Their patient, a 60-year-old man, presented with chills, cough and breathing difficulties. Radiological examination revealed no abnormalities. Colleagues prescribed ceftriaxone plus azithromycin, and after that the nightmare was over. A month later, the scene repeated itself. This time the patient was acutely hypoxic. When looking at the lung CT, doctors found an infiltrate of unknown origin. A fresh lead appeared some time later. The man had in fact regularly consumed cigarettes whose smoke also contains diacetyl. However, on both days before admission he had consumed excessively strongly flavoured e-cigarettes containing diacetyl. Atkins and Drescher believe that bronchiolitis obliterans is probably the correct diagnosis and advised abstinence from e-cigarettes. Konstantinos Farsalinos of the University of Patras expresses doubt about the diagnosis in his blog. Rather, he suspects an exogenous allergic alveolitis (hypersensitivity pneumonitis). It should be mentioned on validity limitation grounds that Farsalinos regularly receives funds from the e-cigarette industry for research projects. The fact that diacetyl leads in the long term to lung damage is beyond doubt.
Freaks when eating
Here is an additional example from the United States. Three years ago Wayne Watson’s story travelled through the media. He was fond of popcorn from the microwave – hardly a day passed without having the delicious sweets. Over years he breathed in diacetyl during its preparation. This volatile additive guarantees delicious butter flavour. Watson’s lung function deteriorated imperceptibly until pulmonologists diagnosed a case of bronchiolitis obliterans. The 61-year-old man is now chronically ill, but richer by 7.2 million dollars. This sum had to be shelled out by the manufacturer and a supermarket because their packaging lacked the appropriate warnings. According to the National Institute for Occupational Safety and Health (NIOSH) already 15 years ago there were pieces of evidence indicating that diacetyl could lead to severe health problems.
Protection on the assembly line
This originally concerned workers in popcorn factories who had been exposed over long periods of time to synthetic flavourings (“popcorn workers lung “). Whether diacetyl in fact – as suspected in an earlier study [Paywall] – promotes amyloid beta aggregation and is connected to Alzheimer’s disease is a subject of controvery among scientists. However the pneumological aspects of the picture delivered sufficient evidence to the courts. They sentenced corporations to make payments totalling $ 100 million to sufferers. In 2007 the “Popcorn Workers Lung Disease Prevention Act” followed. Since then, the US Occupational Safety and Health Authority has set and enforced binding standards for dealing with diacetyl. Nevertheless, diacetyl remains approved in the USA – and not only as an additive to popcorn but also as a component of liquids in e-cigarettes. The situation in Europe is no different. The European Food Safety Authority (EFSA) currently has a “wait and see” stance on the matter.