Regardless of what they tell you at the tanning salon, tanning beds can and do cause skin cancer. In fact, according to new research at the University of Dundee, tanning beds are twice as likely to cause skin cancer as lying out in the sun. Scientists found that the average tanning bed in the UK is emitting harmful radiation that is twice as high as the recommended safe level.

The study correlates with the World Health Organization’s warning that tanning beds are just as dangerous as smoking cigarettes—the organization lists them as one of its most dangerous, cancer-causing habits.

This situation is unacceptable and stricter control measures must be put in place,” researcher Harry Mosely said. “The development of high-power sunlamps, along with clear failures of the sunbed industry to regulate themselves effectively, is putting young people at an even greater risk of skin cancer than we previously thought.”

In their study, which was published in the British Journal of Dermatology, researchers tested radiation emitted by tanning beds at 402 English salons. They found that 90 percent of the tanning beds were emitting radiation levels higher than the safety standards set by the European Union. One bed, in fact, was producing radiation so strong it was six times more likely to cause skin cancer than direct Mediterranean sunlight.

The study’s findings support research that shows cases of malignant melanoma in the UK have doubled in the past 10 years. According to Cancer Research UK about 13,000 British residents are diagnosed with melanoma each year, and about 2,800 die each year.

Other research has found that those older than 35 who use a tanning bed increase their risk for malignant melanoma by almost 90 percent. That doesn’t mean it’s safer for younger people, though. The Centers for Disease Control states those who begin tanning before age 35 increase their risk of melanoma by 75 percent. In fact, California, Vermont, the UK, Germany, Scotland, France and several areas of Australia have banned indoor tanning for those under the age of 18. And Brazil and one Australian state have banned the beds completely.