January 2014 in “한국미용학회지” This study observed that long-term UV-A exposure and semi-permanent dye treatment can cause significant structural damage to human hair, particularly affecting the cuticle and cortex layers.
January 2017 in “Nihon Keshouhin Gijutsushakaishi/Journal of S C C./Nihon Keshouhin Gijutsushakai kaishi” This study found that hair damage from sunlight and chemical processes like perms and bleaching varies in internal microstructure changes, suggesting that protective techniques should be tailored to the type of chemical treatment used.
18 citations
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March 2009 in “Skin pharmacology and physiology” This study found that sunlight exposure causes significant structural and chemical damage to hair, including cuticle loss, cortex damage, and discoloration, with water playing a major role in discoloration of brown hair.
January 2008 in “대한미용학회지” This study reports that prolonged UV irradiation causes progressive damage to the hair's keratin structure, leading to increased surface roughness, cuticle destruction, and decreased tensile strength in young women’s hair.
15 citations
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January 1992 in “Sen'i Gakkaishi” This study suggests that the cell membrane complex in hair cuticles contains hydrophilic regions with disulfide bonds allowing polymer uptake and hydrophobic lamella-like lipid layers.