A study of the sources of external metal contamination of hair

Sources of external metal contamination of hair were examined experimentally by exposing hair samples to soil, hot water from a water boiler for domestic use and household dust and fumes in a kitchen. Copper concentration in the hair increased markedly only when the hair was exposed to hot water from the boiler. Iron concentration in the hair increased markedly after exposure to wet soil, and increased slightly after exposure to hot water from the boiler. There was a slight decrease in zinc in the hair after exposure to wet or moist soil, and a significant increase after exposure to hot water from the boiler. When the hair was exposed to household dust and fumes, zinc showed a slight increase but copper and iron showed no change at all. The experiments with soil demonstrated the importance of water in the movement of iron from soil to hair and the role played in this process by biological factors such as soil bacteria.