Beryllium (Be) has been found in the hair, but documentation correlating exposure, tissue levels and hair levels is lacking. Therefore Be is measured in hair primarily for investigational purposes. Be can be toxic to humans and animals. Be is a biological antagonist of magnesium. Be has a long-term effect of inducing abnormal activity in T lymphocytes, causing immune dysregulation and hypersensitivity reactions.

In animals, Be has been shown to induce rickets and to damage liver, kidney, lungs, and skin. Be is poorly absorbed in the gastrointestinal tract but is readily absorbed by the skin and lungs. Inhalation is the primary route of exposure to Be and chronic uptake results in dyspnea, cough and pulmonary distress (Am. Rev. Respir. Dis.; 173:464-473, 1988).

Possible sources of Be are: electronic components, metal alloys used in aircraft and aerospace applications (especially aluminum-copper-beryllium alloys), bearing sleeves, optical lens coatings, and some phosphors in fluorescent lights. Tobacco contains Be, and smoking immediately increases the Be levels in the blood and urine.

A confirming test for Be exposure is urine elements analysis. Be is slowly excreted in urine and may be found elevated many months after the exposure.