Fig. 1. Wavelength characteristics of the Exo Terra Repti Glo® fluorescent light bulbs
(Terra, Mansfield, MA) designated 2.0 (low UV-B) and 10.0 (high UV-B) 26-watt
fluorescent UV-B emitting bulbs. The spectra of the 2.0 and 10.0 bulbs were measured
using a Stellarnet model EPP2000 spectrometer (Tampa, FL) equipped with a
fiber-coupled, quartz diffuser fore optic. The weighted irradiance energy or intensity
of radiation of the 2.0 or ‘low UV-B’ bulbs and 10.0 or ‘high UV-B’ bulbs was
3.12 mW/m2 and 22.1 mW/m2, respectively, estimated using the erythemal action
spectrum of McKinlay and Diffey (1987) used to measure the carcinogenic effectiveness
on human skin. The erythemal action spectrum is useful in comparing the
relative effectiveness of different wavelengths producing a biological response. The
lamps used here differ in their spectra at longer wavelengths. The higher energy
UV-B portion, which carries the greatest weighting, is assumed to be most effective
at eliciting a reaction.