Cobalt cardiomyopathy. A report of two cases from mineral assay laboratories and a review of the literature.

Two young men employed in the mineral assay industry developed non-inflammatory cardiomyopathy. By review of clinical findings, elicitation of occupational and environmental histories, work-site evaluations, and ascertainment of tissue cobalt levels, Nevada Public Health authorities confirmed these cases to be due to occupational cobalt exposure. Hair and heart cobalt levels were elevated for the cases, but control samples had no detectable cobalt. Excess ischemic heart disease mortality among cobalt-exposed workers may reflect misdiagnosis of cardiomyopathy.