[Table/Fig-1]:

Sources of DNA damage UV Rays –Ultraviolet Rays

Endogenous sources	Exogenous sources
Reactive oxygen species, a product of normal metabolic process.	Plant toxin
Estrogen metabolites	UV-rays, X-rays and gamma rays
Methylating agents, Reactive nitrogen species	Mutagenic chemicals like arsenic, mercury etc. that act as DNA intercalating agents
Hydrolysis of the glycosylic bond in DNA, and hydrolytic deamination	Chemotherapeutic agents and radiotherapy
Carbonyl stress (Reactive carbonyl species)	Viruses