Table 2.

Landmark papers establishing the principle of cumulative damage

Principle Established	Year	First author [Reference]
Repeated exposure to suberythemal doses of UV will eventually result in erythema	1981	Parrish JA [36] Kaidbey KH [34]
Chronic, low dose UV exposure lowers the MED	1981	Parrish JA [36] Kaidbey KH [34]
Threshold doses established	1981	Kaidbey KH [34]
Minimum recovery time determined	1983	Arbabi L [38]
Chronic, low dose UV exposure induces cellular changes	1995	Lavker RM [37]