All six labs used a variety of methods to remove external contamination, however, no standardized procedure for hair sample collection and preparation exists to ensure consistency and reliability. How much of the lab results were due to external chemicals coating the hair or penetrating the hair shaft from the outside is unclear. In addition, reference ranges, which are values considered normal for a person's age, environment, and hair quality, varied widely between laboratories. Minerals and potential toxins are transported in very dilute concentrations in the blood. Since blood bathes growing hair follicles, these elements are incorporated into the structure of the hair's protein.
Toxic minerals can concentrate in the hair at several hundred times higher than blood.
Although minerals such as calcium, chromium, selenium are among the more commonly analyzed minerals, not all elements in hair are considered to accurately reflect levels in the body. Although further research may be needed to examine the validity of using the hair analysis test in different clinical situations, this study underlined the even greater need to establish standardized lab protocols and reference ranges. Barrie S. Heavy metal assessment. Textbook of Natural Medicine. Churchill Livingstone, 161-175. 2.