New research presented at the European Respiratory Society International Congress has revealed how e-cigarettes can put smokers at a higher risk of respiratory problems, especially for those who smoke e-cigs alongside traditional tobacco cigarettes.
The two separate studies were carried out by researchers from Umeå University, Sweden, and the University of Crete, Greece, with the findings presented at the Congress, which is currently taking place in Milan, Italy, (from September 9 to 13).
Dr Constantine Vardavas (MD, PhD), from the University of Crete presented his research on the content of e-cigarette refills, which analyzed exactly which chemicals were present in e-cigarette liquids, and in what quantities, from the most popular brands on sale in Greece, Spain, Germany, The Netherlands, the U.K., Hungary, Romania, Poland and France.
The study looked at 122 of the most commonly sold e-cigarette liquids in total and included a variety of different flavors and nicotine strengths.
They found that every liquid tested contained at least one substance that is classified as a health risk according to the United Nations (UN) classification system.
According to their classification, some of these substances "may cause allergy or asthma symptoms or breathing difficulties if inhaled," while others are "able to cause respiratory irritation."
In another study presented at the congress, Dr. Linnea Hedman from Umeå University, Sweden, revealed that after surveying more than 30,000 people in Sweden about their smoking habits, use of e-cigarettes and respiratory symptoms, the team found that those who use both tobacco and e-cigarettes experience more respiratory problems symptoms, such as a persistent cough, wheezing and coughing up mucus.
Among non-smokers 26 per cent experienced at least one respiratory symptoms, compared with 34 per cent among those using only e-cigarettes, 46 per cent among those only smoking conventional cigarettes, and 56 per cent among dual users.
The results showed that e -cigarette use was also more common among people who currently smoke conventional cigarettes (9.8 per cent), compared to former smokers (1.1 per cent) or non-smokers (0.6 per cent).
"The possible health effects of e-cigarettes are far from established and it will take some years before the long-term effects will be revealed," commented Dr. Hedman, "However, this research adds to the evidence that e-cigarettes cannot yet be marketed as a safe alternative to conventional cigarettes."
In another much smaller study presented at the Congress, Dr. Magnus Lundbäck from Danderyd University Hospital, Karolinska Institute, in Stockholm, Sweden, revealed that after looking at 15 young and healthy participants, the team also found for the first time that e-cigarettes with nicotine can cause a stiffening of the arteries in humans, an important finding as arterial stiffness is associated with an increased risk of heart attacks and strokes in later life.
