Application of Monte Carlo track structure has been very successful in the modelling and quantification of DNA damage, clustered-damage and spectrum of DNA damage for energetic electrons and ions. However, there are paradoxical axioms in quantitative assessment of the energetics of DNA damage at very low electron energy and in the vacuum UV region. This paper, after a brief review of the parameters used in modelling of DNA damage, presents an analysis of experimental data of strand breaks in aqueous solution in the vacuum UV, the region to which little attention has been paid in spite of its fundamental importance in providing reaction parameters for radiation actions.