Morphological and Physical Changes in Hair Due to UV Irradiation

This study investigated the effects of UV irradiation on the hair of women in their 20s, focusing on formal and physical changes over time. It was found that UV exposure caused the smooth surface of natural hair to become rough, with significant damage observed after 1 hour, including cuticle destruction and surface cracks. After 3 hours, the cuticle was almost completely destroyed, and by 12 hours, the cortex began to collapse and be penetrated, indicating damage to the hair's keratin. Additionally, the tensile strength of the hair decreased over time, suggesting that prolonged UV exposure negatively affected the peptide bonds, further weakening the hair structure.