Although indoor tanning devices are already linked to the most deadly form of skin cancer, melanoma, researchers say they also trigger other damaging forms of the disease.
Researchers, led by Professor Eleni Linos at the University of California San Francisco, estimate that indoor tanning may account for over 170,000 cases of non-melanoma skin cancer in the US alone.
Linos and her team analysed the results of 12 studies involving 9,328 cases of non-melanoma skin cancer (7,645 basal cell carcinomas and 1,683 squamous cell carcinomas).
Using indoor tanning was associated with a 67 per cent higher risk of developing squamous cell carcinoma and a 29 per cent higher risk of developing basal cell cancer, compared with never using it.
Researchers estimated that such tanning accounts for 3.7 per cent of cases of basal cell carcinoma and 8.2 per cent of cases of squamous cell cancer.
This corresponds to 98,408 cases of basal cell cancer and 72,244 cases of squamous cell carcinoma, making 170,652 cases of non-melanoma skin cancer each year attributable to indoor tanning.
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Exposure before 25 years of age was significantly associated with an increased risk for basal cell carcinoma and showed a non-significant increased risk for squamous cell cancer.
"This suggests a critical period for exposure during early life and a potential dose-response effect," researchers said in a statement.
Researchers say their findings point to a possible causal link between indoor tanning and non-melanoma skin cancers and they estimate that indoor tanning "may account for hundreds of thousands of new cases each year in the United States alone."