Photodegradation of Hair of Different Ethnicities After One Year of Exposure to Natural Weathering in Arizona

March 2007 in “ International Journal of Cosmetic Science ”

Y. K. Kamath, S. B. Ruetsch

photodegradation hair fibers thinning scale fusion inter-fiber fusion radial cracks scanning electron microscopy UV-visible microspectrophotometry melanin photochemical degradation UV-visible spectroscopy SEM

TLDR Hair with more melanin resists weather damage better.

The study investigated the photodegradation of hair from different ethnicities after 1 year of exposure to natural weathering in Arizona. Hair fibers exhibited significant changes, including thinning, fusion of scales, and inter-fiber fusion, resulting in rigid and brittle hair with radial cracks. Scanning electron microscopy and UV-visible microspectrophotometry revealed that melanin in hair provides protection against photochemical degradation. Indian and Chinese black hair, which are rich in melanin, showed better resistance to degradation compared to European hair with lower melanin content.