Hair analysis in environmental medicine.

Hair analysis comprises the determination of minerals, trace elements and drugs. It is applied in Germany with increasing frequency in the recently established field of environmental medicine for biological monitoring of the internal metal/metalloid exposure. Besides a number of advantages hair analysis is impaired by the difficulty-to distinguish between endogenous and exogenous sources of metals in hair. Except for methylmercury, there are no critical limit values for trace elements in hair available. However, valid reference values for some metals and for nicotine in hair have been recently presented in the German Environmental Survey. The significance of selected substances in hair are as follows: Aluminium in hair is of no value in environmental medicine. For assessment of cadmium and inorganic arsenic exposure hair analysis is only suitable as a screening method based on large populations. Monitoring of lead in hair is a valuable screening method also for small groups, especially for children. Based on toxicokinetics and under consideration of practicability the optimal biomarker of methylmercury exposure is the hair concentration. For other mercury compounds hair analysis is of lower significance. Nicotine and cotinine measurements in hair provide a practical and proper method for estimating environmental tobacco smoke exposure and to validate smoker status in epidemiological studies.