People who like to bask in the blue glow of indoor tanning beds could double their risk of developing melanoma -- the deadliest form of skin cancer, new research has found.

The study found people who have tanned indoors have on average a 74 per cent higher risk of developing melanoma than people who have never tried it. And the more that people tan and the longer they tan, the more the risk increases.

The research, published in the journal Cancer Epidemiology, Biomarkers & Prevention, found that those who frequented tanning salons for more than 10 years, or who logged more than 100 sessions, were about 2.5 times more likely to develop melanoma compared to those who had never tried indoor tanning.

Those who spent more than 50 hours under the lights in their lifetime were three times more likely to develop the cancer.

The study looked at 1,167 people in Minnesota who had developed melanoma from 2004 through 2007, along with 1,101 people who did not have skin cancer. The researchers conducted interviews and had patients complete questionnaires about their indoor tanning practices, when they began tanning, for how long, and the devices used.

They found that among those with melanoma, almost two-thirds (63 per cent) had used tanning beds. And among those who used tanning beds, the risk for developing melanoma rose 74 per cent.

The risk for melanoma was significant whether the tanning beds used both UVA and UVB rays or UVA rays only.

"It had been previously thought that those tanning with UVB, rather than UVA, radiation would be at increased risk for melanoma. Our study shows that there is no such thing as a safe device," Lazovich said in a news release.

She noted that what was most remarkable about her team's results was that they were consistent across both genders, all ages, by where the cancer was found, or by what device they used.

The International Smart Tan Network (Smart Tan), an industry group representing indoor tanning retailers, says the study is flawed and overstates the risks of indoor tanning. It notes that the risk of melanoma is low, regardless of a person's tanning practices.

"In suggesting that tanners double their risk of melanoma, the authors mention only relative risk figures in the paper, ignoring that more telling figure that the absolute risk of melanoma is quite low for both tanners and non-tanners," the groups said in a news release.

Melanoma is the least common, but most serious, type of skin cancer. It is estimated that 5,300 new cases of melanoma will be diagnosed in Canada in 2010. About 1,000 of those people will die of the disease.