Photodegradation of Human Hair: A Microscopy Study
January 2001
in “
Comprehensive series in photosciences
”
UV radiation hair fibers cuticle cells cuticular sheath chemical oxidation melanin granules photochemical oxidation alkaline hydrogen peroxide microfluorometry UV microspectrophotometry UV stabilizers photodegradation UV light hair strands cuticle hair sheath oxidation melanin hydrogen peroxide fluorescence microscopy UV spectroscopy UV protectants
TLDR UV radiation significantly damages hair, especially with humidity, making it more vulnerable to further damage.
This study investigated the effects of UV radiation on hair fibers using various microscopy techniques. It found that long-term UV irradiation and humidification cycling caused significant damage, including thinning and fusion of the cuticle cells and cuticular sheath. Even without humidification cycling, UV exposure at low humidity still led to similar damage upon post-treatment with water. Chemical oxidation dissolved melanin granules, while photochemical oxidation did not significantly alter them. However, UV irradiation combined with humidification made the hair more susceptible to damage from alkaline hydrogen peroxide. Techniques like microfluorometry and UV microspectrophotometry were used to quantify hair damage and assess the effectiveness of UV stabilizers, showing that uniform distribution and high uptake of stabilizers were crucial for protection against photodegradation.
