The Concentration of the Potentially Toxic Metals in Human Hair, Nails, Urine, Blood, and Air, and Their Impact on Human Health: A Review

Due to fast urbanization, industrialization, the metal industry, improper waste disposal, and chemicals associated with agricultural activities (fertilizers, pesticides), potentially toxic metals are discarded in water, soil, and the atmosphere (air). These metals enter the body through food, water, and air and accumulate. Some of these metals affect biological functions and growth in the body; some disturb endocrine gland functions; and some are accumulated in one or more organs, causing serious diseases including cancer. To assess the potential health risk due to the accumulation of these metals in the human body, biomarkers are used. Hair, nails, urine, and blood are commonly used biomarkers. The review aims is to summarize the concentration of potentially toxic metals in human hair, nails, urine, and blood. The feeding habits (vegetarian or non-vegetarian), sex, age, and concentration of these metals in drinking water, air, smoking, and workplace are some factors that affect the accumulation of these metals in hairs, nails, urine, and blood. The concentration of these metals in hair, nails, and blood was higher than in drinking water. This review also shows the adverse effects of these metals on humans