The pitfalls of hair analysis for toxicants in clinical practice: three case reports.
Environ Health Perspect 2002 Apr; 110(4):433-436
Hair analysis is used to assess exposure to heavy metals in patients presenting with nonspecific symptoms and is a commonly used procedure in patients referred to our clinic. We are frequently called on to evaluate patients who have health-related concerns as a result of hair analysis. Three patients first presented to outside physicians with nonspecific, multisystemic symptoms. A panel of analytes was measured in hair, and one or more values were interpreted as elevated. As a result of the hair analysis and other unconventional diagnostic tests, the patients presented to us believing they suffered from metal toxicity. In this paper we review the clinical efficacy of this procedure within the context of a patient population with somatic disorders and no clear risk factors for metal intoxication. We also review limitations of hair analysis in this setting; these limitations include patient factors such as low pretest probability of disease and test factors such as the lack of validation of analytic techniques, the inability to discern between exogenous contaminants and endogenous toxicants in hair, the variability of analytic procedures, low interlaboratory reliability, and the increased likelihood of false positive test results in the measurement of panels of analytes.
Toxins; Analytical-processes; Analytical-methods; Metal-poisoning; Metal-workers; Somatic-nervous-system
B.S. Schwartz, Division of Occupationl and Environmental Health, Johns Hopkins Bloomberg School of Public Health, Room 7041, 615 North Wolfe Street, Baltimore, MD 21205 USA
Environmental Health Perspectives
Johns Hopkins University