Figure 3

Quantitative model describing DNA damage processes. UV radiation directly causes DNA damage by the formation of thymine dimers or the generation of ROS radicals (red circles) at bacteria by UV radiation, which damages DNA. The rates of DNA damage are described as follows: Γ₀ (cm²/mJ): UV radiation directly causes DNA damage by the formation of thymine dimers, Γ₁ (cm³/s): ROS radicals damage DNA, Γ₂ (cm²/mJ): ROS radicals are generated at the bacteria by UV radiation, Γ₃ (s⁻¹): lifetime of ROS radicals, and Γ₄ (cm³/s): mutual destruction of ROS radicals.