Virucidal Properties of Light and SO 2 I. Effect on Aerosolized Venezuelan Equine Encephalomyelitis Virus

Abstract

Summary

A combination of 3.6 ppm of SO₂ gas and 308 meal cm^-2 min^-1 of simulated solar radiation were highly toxic in tests employing airborne Venezuelan equine encephalomyelitis virus as a model. Under these conditions, the virus decayed more rapidly at 60% RH than at 30% RH (decay rates of 40%/min vs 25%/min, respectively). Although both pollutant and light were toxic when employed separately, the viral response to a combination of the two was much greater than the sum of the separate effects, suggesting that an interaction had occurred. Lowering the light intensity to 40 meal cm^-2 min^-1 produced a similar although decreased effect at 60% RH, At 30% RH, however, the SO₂-light combined effect was not found; in this case, SO₂ alone effected viral inactivation to a significantly greater degree than either light alone or the SO₂-light combination. The data suggest that, in this case, the low intensity of light acted upon the SO₂ directly, preventing it from attacking the virus.