Biological materials have gained an irreplaceable position as a bio-indicator for environmental pollution with heavy metals. Human hair and nails have come to play an important role in this subject according to the recommendations by the World Health Organization (WHO). The levels of selected toxic and heavy metals (Pb, Zn, Cd, and Ni) in the fingernails and scalp hair of autoworkers in Saudi Arabia were estimated to study exposure to chemical pollutants metals. The samples were collected from different ages of male autoworkers (car mechanics, auto welding, repair car tires washing, and oil change services center) and office workers (control) volunteers in Hail city. The analysis was performed using inductively coupled plasma mass spectrometry (ICP-MS) after microwave acid digestion at their recommended conditions. The data obtained from office workers (control) samples were used for this purpose. A systematic analysis investigation was done for all samples taking into consideration the age and experience per year. As a result of this research, it has been revealed that there was a statistically significant relationship between the type of work (autoworkers) or workplace and the heavy metal concentration detected in fingernails and scalp hair samples, which represent a very important guide for the labor and health organizations. This result proved that fingernails and scalp hair could be used as a good biological indicator for the assessment of toxic heavy metal pollution.
