Table 1. Estimated frequencies of DNA lesions caused by endogenous and common environmental sources of DNA damage.

Adapted from Friedberg, 2006; Lindahl, 1993; Sander et al., 2005; Sears and Turchi, 2012; Mouret et al., 2006.

Endogenous DNA adducts
DNA lesion	DSB	Cytosine deamination	Cyclopurine adducts	Depyrimidination	8-oxoG	Malondialdehyde adducts	Alkylation adducts	Depurination	SSB
Frequency per cell per day	101	102	102	102	103	103	103	104	104
DNA adducts caused by environmental exposures
Genotoxin	Sunlight	Background radiation			Ionizing radiation therapy		Oxaliplatin cancer therapy
Lesion	Photodimers	Damaged bases	SSB	DSB	Damaged bases	SSB	Intra- and interstrand crosslinks
Frequency per cell per day	102 in skin cells only	10	2–5	0.25	103	103	103