title: [Solar exposure time for sunburn in Mexican population].
abstract: BACKGROUND
  THe minimal erythemal dose (MED) quantifies an individual's sensitivity to UV radiation (UVR). To estimate it in our population and establish the time of exposure inducing it during daily activities would allow us to calculate risk intervals.
  
  
  METHODS
  From 2005-2012, the UV solar radiation was measured with terrestrial radiometry and compared to public UV index (UVI). We determined the MED in 90 individuals with the prevalent phototypes in Mexico (III, IV, V), and estimated the time needed for the development of sunburn.
  
  
  RESULTS
  The average MED for phototype III was 39 (IC 95%: 35-42) mJ/cm2, for IV 48 (IC 95%:42-53) mJ/cm2, and for V was 84 (IC 95%:75-92) mJ/cm2 (ANOVA, p ≤ 0.001). Approximately, 80% of the daily UVR was accumulated between 10:00-16:00 h, and 77% of the annual UV dose is received between March-October. The public UVI had a high correlation with the one quantified at terrestrial level (r = 0.89; p ≤ 0.001).
  
  
  CONCLUSIONS
  Mexico receives continuously high levels of UVR. Phototype III will present sunburn after 22-33 min in a summer day, while phototype V will require over one hour of exposure. This last group is at risk of chronic exposure without considering consequences.
authors: Departamento de Dermatología, Hospital Central Dr. Ignacio Morones Prieto, Universidad Autónoma de San Luis Potosí, SLP, México. castanju@yahoo.com
authors: Juan Pablo
authors: JP
authors: Castanedo Cázares
authors: Bertha
authors: B
authors: Torres Álvarez
authors: Salvador
authors: S
authors: Sobrevilla Ondarza
authors: Adriana
authors: A
authors: Ehnis Pérez
authors: Antonio
authors: A
authors: Gordillo Moscoso
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D013471:Sunburn / Q000453:epidemiology* / Q000209:etiology*; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects; D055815:Young Adult