Table 1.

Criterion for each risk factor (n = 127)

Risk factors (total range)Criteria
Sunlight-exposure time
1 d before (0–6 h/d)a≥2 h/d
2 d before (0–10 h/d)b≥2 h/d
Ratio of sunlight-exposed skin area to the whole body
1 d before (0–0.63)a≥0.2
2 d before (0–0.63)b≥0.2
Sunlight intensity
1 d before (0–59.5 mW/cm2)a>30 mW/cm2
2 d before (0–42.9 mW/cm2)b>30 mW/cm2
L*-value (lightness)
Sole (59.08–76.08)≥68
Forehead (49.52–66.29)≥63
Difference (sole minus forehead; −1.47 to 18.53)<9
Sunscreen
Never and irregular use or regular useRegular use
  • aOne day before the day of urine sample collection.

  • bTwo days before the day of urine sample collection.