The photosensitizing action of carcinogens. I. The action of 2-naphthylamine on Escherichia coli K-12 and Paramecium caudatum.

Abstract

Cultures of Paramecium caudatum incubated with 7 × 10−7 M 2-naphthylamine were rapidly killed when exposed to light of 366 nm. Cultures not exposed to the amine were unaffected by the light; cultures kept in the dark were unaffected by the amine. Escherichia coli K-12 populations were markedly reduced after irradiation of suspensions in water containing 3 × 10−4 M 2-naphthylamine with light simulating natural sunlight in intensity and wavelength distribution. Suspensions of E. coli in deionized water were unaffected by the light and E. coli suspended in solutions of the amine but kept in the dark were also unaffected. Since 2-naphthylamine is a known water pollutant these results may be of ecological importance.