Davis Instruments 6152C Weather Radio User Manual


 
44
UV MEDs
MED (Minimum Erythemal Dose) is defined as the amount of sunlight exposure neces-
sary to induce a barely perceptible redness of the skin within 24 hours after sun expo-
sure. In other words, exposure to 1 MED will result in a reddening of the skin. Because
different skin types burn at different rates, 1 MED for persons with very dark skin is
different from 1 MED for persons with very light skin.
Both the U.S. Environmental Protection Agency (EPA) and Environment Canada have
developed skin type categories correlating characteristics of skin with rates of sunburn.
T
ABLE A-1: EPA SKIN PHOTOTYPES
Skin Phototype Skin Color Tanning & Sunburn history
1 - Never tans,
always burns
Pale or milky white;
alabaster
Develops red sunburn; painful swelling,
skin peels
2 - Sometimes tans,
usually burns
Very light brown;
sometimes freckles
Usually burns, pinkish or red coloring
appears; can gradually develop light
brown tan
3 - Usually tans,
sometimes burns
Light tan; brown, or
olive; distinctly
pigmented
Rarely burns; shows moderately rapid
tanning response
4 - Always tans;
rarely burns
Brown, dark brown, or
black
Rarely burns; shows very rapid tanning
response