Tanning beds have always been controversial. Now, an influential cancer advisory group is saying they're not just risky; they're "carcinogenic."

The International Agency for Research on Cancer (IARC), the World Health Organization's leading source for information about cancer, announced Tuesday it has moved tanning devices up to its highest cancer risk category, group 1: "carcinogenic to humans."

Until now, sunlamps and tanning beds were classified as "probably carcinogenic to humans," or group 2A.

The IARC researchers, led by noted oncologist Dr Fatiha El Ghissassi, issued their report after reviewing studies that found consistent evidence of a link between tanning beds and the skin cancer melanoma as well as a form of eye cancer called ocular melanoma.

"A comprehensive meta-analysis concluded that the risk of skin melanoma is increased by 75 per cent when use of tanning devices starts before 30 years of age," the authors write in a special report in the August edition of The Lancet Oncology.

"Additionally, several case-control studies provide consistent evidence of a positive association between the use of UV-emitting tanning devices and ocular melanoma. Therefore, the Working Group raised the classification of the use of UV-emitting tanning devices to Group 1, 'carcinogenic to humans'."

The group also moved ultraviolet radiation as a whole into group 1 from group 2A.

Ultraviolet radiation, from sunlight exposure or an artificial source such as tanning beds, can damage the DNA in the nuclei of skin cells and can affect the ability of cells to repair the various forms of UV-induced DNA damage.

The IARC group says they are most concerned about the link between tanning beds and melanoma, a form of skin cancer that's expected to be diagnosed in 5,000 Canadians this year and kill about 940 Canadians.

"I think the Lancet study gives a bit more validity and increases the amount of concern patients should have with respect to ultraviolet radiation, especially artificial sources such as sunning beds," Dr. Ronald Vender, a dermatologist at St. Joseph's Healthcare Hamilton, told CTV Toronto in reaction to the IARC's move.

"The bottom line is, there is no such thing as a safe tan."

Tanning industry dismisses report

The Joint Canadian Tanning Association offered their response to the IARC study by noting that the report "presents no new data, ignores confounding information, and attempts to reach a new conclusion with no new information."

"While it remains prudent for individuals to avoid sunburn, it should be noted that there is no research suggesting that non-burning UV exposure is a significant risk factor for humans. None," JCTA President Doug McNabb said in a statement emailed to CTV News.

"Further, it is more clear now than ever that humans NEED regular UV exposure as the only true natural way to make vitamin D. It is called "The Sunshine Vitamin" for a reason -- you make more vitamin D simply getting a tan in a non-burning fashion than you would from drinking 100 glasses of whole milk.

"We are very concerned that the politics of anti-UV groups is misrepresenting the balanced message about sunlight that a true, independent evaluation of the science supports. If a pharmaceutical company sold you sunshine, we wouldn't be having this discussion right now."

Group calls for ban on tanning beds for teens under 18

Just three weeks ago, doctors attending the Canadian Dermatology Association's annual meeting in Vancouver noted the worrying rise of melanoma among young patients.

They said young people aged 15 to 29, especially women, seem to be particularly vulnerable to melanoma, noting that is has become the third most common form of cancer in young Canadian women.

The Canadian Dermatology Association contends that no one under the age of 18 should use a tanning bed, a position the World Health Organization has taken since 2005.

 The CDA has been lobbying provincial governments to ban tanning beds for those younger than 18 yet there have been little action from government to regulate the industry. Only New Brunswick bans teens under 18 from using the beds.

In 2005, Health Canada issued voluntary guidelines for tanning salon owners and users which suggest that salon operators not allow youth under 16 to tan. But a 2007 survey by the Ontario division of the Canadian Cancer Society found that 60 per cent of tanning facilities did not ask the age of young tanners.

The Canadian Cancer Society says it isn't just youth who should stay away from tanning salons. Anyone who is fair-skinned, has freckles or moles or burns easily should also never use a tanning bed. Neither should anyone who's ever had skin cancer or a family history of skin cancer.