Studying the arsenic absorption by keratin protein extracted from human hair

Abstract

Elevated levels of the element arsenic in the human body cause Arsenic poisoning. A strong correlation exists between the intake of Arsenic and harmful health effects. While Arsenic exposure can occur from air, food and water, major Arsenic poisonings have been caused by water and this, in most cases is the predominant exposure route. Elevated arsenic concentrations occur naturally in deeper levels of groundwater. In consequence, removing Arsenic from water has become extremely necessary. In water it is present majorly present in trivalent and pentavalent form. The trivalent form stays as a neutral species in water, making it extremely difficult to eliminate. Before subjecting it to any other removal techniques, it is generally oxidised to pentavalent state.
Arsenic gets deposited on certain sites of the human body, such as hair, nails, skin etc. This indicates the Arsenic absorptive ability of human proteins. This remarkable property of proteins propelled us to study and analyse more.
Human hair which is normally a waste product has been used to study the Arsenic absorptive property of the keratin protein and its efficacy as a water purifier. Here we extract proteins from human hair, to create human hair matrix for the study of trivalent arsenic absorption by the de-proteinized hair. A solution of arsenic trioxide is used as test solution to ensure the presence of arsenic in trivalent form. Shindai method is used for protein extraction. The extracted protein is characterised by using several techniques such as Electrophoresis, X-Ray Diffraction, Scanning Electron Microscopy, Differential Scanning calorimetry, Fourier transform Infrared spectroscopy and Energy-dispersive X-ray spectroscopy. The increased concentration quantification and thus the absorption of Arsenic on the hair is tested by the Arsen 10 Test.