[en] The use of tanning booths as a substitute for natural sunlight is becoming increasingly popular. However, unless careful attention is paid to proper design and maintenance, the radiation field inside a tanning booth can be highly anisotropic. The use of simple, inexpensive ultraviolet radiation meters to measure dosage can lead to serious overexposure. Since the ultraviolet radiation inside a tanning booth has a greater proportion of short wavelengths (less than 300 nanometers) than natural sunlight, the amount of skin cancer-inducing radiation received for a tan may be twice that received for a natural suntan