Radiation Effect on Viruses
Reduction of reoviral cytotoxicity.
Radiation does not affect viral replication of some viruses and only reduces reoviral cytotoxicity. Examples of these are viruses of Reoviral family, e.g. rotavirus.
It also causes inactivation
UV rays can damage the DNA of living organisms by creating nucleic acid dimmers. However, the damages are usually not important due to low penetration of UVs through living tissues. UV rays can be used, however, to inactivate viruses since virus particles are small and the UV rays reach the genetic material, inducing the dimerization of nucleic acids. Examples of these viruses which are inactivated are; encephalitis virus, murine polyoma viruses, encephalomyocarditis virus(EMCV).
UV radiation also kills viruses
UV radiation can kill viruses by genetically modifying their genetic material DNA/RNA. The most effective wavelength for inactivation is 260nm. Example is influenza viruses which can be killed by visible light.
UV radiation cause mutagenesis
E.g. for SS DNA Parvovirus's. Mutation induction in the progeny of UV radiation virus increase linearly with the dose and can be ascribed neither to an increased number of viral replication nor to the indirect activation of an inducible cellular motor activated by the UV damaged virus
Reactivation of some viruses
Viral genomes have UV response elements that alter normal interactions between the virus and the host following the exposure to uUV radiation; example is Herpes simplex in which sunlight exposure can cause reactivation and certain papilloma virus types in which sunlight exposure can lead to the development of non melanoma skin cancer.