Increasing biological interest in minerals has led to the search for reliable methods to quantify body levels of trace elements and toxic metals. Hair has been a prime candidate because of its ease of collection and the possibility that this body tissue might accurately reflect body loads of these substances. A vast amount of research effort has been expended to explore the value of hair-element analysis. Unfortunately, there are so many confounding factors that influence these measurements that isolated individual results cannot be relied upon. Their current value is in epidemiological studies.