Potent genotoxicity of halogen lamps, compared to fluorescent light and sunlight

S. De Flora, A. Camoirano, A. Izzotti, C. Bennicelli

Research output: Contribution to journalArticlepeer-review


The light emitted by halogen lamps induced mutations in Salmonella typhimurium and DNA damage in Escherichia coli, as shown by the hypersensitivity of DNA repair-deficient strains. The mutagenicity of halogen lamps was considerably higher than that of fluorescent light and of sunlight, even at much lower illuminance levels. Excision mechanisms and SOS functions were involved in repairing light-induced base-pair substitutions and frameshift errors in bacterial DNA. At variance with solar irradiation, which produces mutagenic effects over a wide UV spectrum, genotoxicity of halogen lamps was almost exclusively due to far-UV wavelengths transmissible through UV-R-250 and UV-R-280 interference filters. The main mutagenic component of fluorescent light was transmitted through the UV-R-280 filter. Far-UV wavelengths (254 nm) were almost 104-fold more mutagenic than near-UV wavelengths (365 nm). All light sources exhibited some residual mutagenicity even following filtration through various cloths. On the other hand, appropriate glass or plastic covers consistently prevented mutagenic effects. This emphasizes the urgent need for a compulsory shielding of halogen and fluorescent lamps in order to prevent unnecessary exposures to genotoxic and potentially carcinogenic UV radiations.

Original languageEnglish
Pages (from-to)2171-2177
Number of pages7
Issue number12
Publication statusPublished - 1990

ASJC Scopus subject areas

  • Cancer Research
  • Physiology
  • Statistics, Probability and Uncertainty
  • Applied Mathematics
  • Physiology (medical)
  • Behavioral Neuroscience


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