Impact of age, gender and chemical treatments on hair damage characteristics: insights for forensic analysis

This study investigates the structural characteristics of human scalp hair to understand the impact of age, gender and chemical treatments on hair damage using compound light microscopy. Hair samples were collected from both male and female which across various age groups and including subjected chemical treatments such as dyeing, rebonding and curling. The samples were analyzed at different segments (top, mid and end) to observe the damage patterns by observing the cuticle, cortex and medulla. Results revealed that younger individuals exhibited intact cuticle layers and uniform shaft morphology, while older age groups showed progressive damage such as cuticle erosion, fraying and pigments loss. Next, due to grooming habits, gender-based differences indicated more frequent surface damage in females. Chemically treated hair demonstrated the most severe structural alterations including disrupted cuticles and uneven pigmentation. These findings highlight how light microscopy and scanning electron microscopy can help forensic investigations, especially when DNA evidence is limited or unavailable by providing structural indicators of age, gender and hair treatments.