Ta. Cebula et al., REVERSION PROFILES OF COOLWHITE FLUORESCENT LIGHT COMPARED WITH FAR-ULTRAVIOLET LIGHT - HOMOLOGIES AND DIFFERENCES, Photochemistry and photobiology, 61(4), 1995, pp. 353-359
General Electric and Sylvania 15 W coolwhite fluorescent lamps emit ro
ughly 6% of their total irradiance as light in the UV spectrum. Illumi
nation of sensitive Salmonella tester strains results in both lethal a
nd mutagenic activities. In contrast, comparable Philips lamps emit lo
wer levels of UV light, especially UVB, and exhibit no detectable leth
al or mutagenic effects. The spectra of mutations induced by General E
lectric coolwhite lamps in histidine-requiring base substitution mutan
ts hisG46 and hisG428 (''reversion profiles'') resemble mutagenesis by
far UV light (UVC) and differ quite markedly from the spectra of muta
tions that occur spontaneously. Coolwhite and UVC reversion profiles a
re not identical, however. The percentage of C to A transversion mutat
ions induced in hisG46 are elevated over those found after UVC treatme
nt, and a strong bias for one particular class of tandem base substitu
tions (TAA --> TGT) prevails after treatment of hisG428 with coolwhite
light, a bias not observed with UVC. Increased attention needs to be
given to minimization of exposure to UV light from fluorescent lamps c
ommonly used in homes and workplaces.