Morphological Effects on Hair Treated with Sodium Hypochlorite

Hair is one of the most frequent trace evidence in crime scene. It is known that hair structure is resistant to external factors but there are a few studies about chemical treatments. This study is about effects of Sodium Hypochlorite (NaClO) to morphological structure of the hair. In this study 10 hairs included for study group and 10 for control group. The hairs were collected by cutting from near the scalp of a Caucasian adult. The study group was treated in household bleach including <5% NaClO for 10 minutes. The other group had no treatment. All of the hairs were mounted on slides with xylene and examined by light microscopy. Colors of the NaClO treated hairs were light brown in 9 hairs and brown in one hair, while 7 of the control smooth and inner margin was distinct in control group while outer surface of the cuticle was wavy except one hair and inner margin was indefinite in NaCIO treated hairs. Moreover we observed that there were many air gaps in the cortex of the NaCIO treated hairs. No cuticular lifting was seen in the hair samples. Many air gaps and decrease of the pigment density were seen in the cortex of the NaCIO treated hairs. It was evaluated that the air gaps were a result of disruption of pigment granules. And in the cuticle; wavy form in the outer surface and becoming indistinct in the inner surface were seen in NaCIO treated hairs. When somebody detects these findings in the morphologic examination of the hair, he/she must consider NaCIO treatment in the differential diagnosis.