Olfactory impairment after chronic occupational cadmium exposure.

Disorders of olfaction affect millions of Americans, but the extent to which occupational and environmental exposures contribute to these disorders is unknown. We examined 55 workers with chronic occupational exposure to cadmium fumes in a brazing operation. We estimated cadmium body burden using urinary cadmium levels and assessed cadmium-induced renal damage by urinary beta 2-microglobulin levels. We quantified olfactory function using a standardized test that measured two components of olfaction, butanol detection threshold and odor identification, and compared workers with a reference group. Forty-four percent of the cadmium-exposed workers were mildly hyposmic, and 13% were either moderately or severely hyposmic. In the reference group, 31% were mildly hyposmic, and the rest were normosmic. The workers with both high urinary cadmium levels and tubular proteinuria had the most significant olfactory dysfunction, with a selective defect in odor detection threshold. Our findings suggest that chronic occupational cadmium exposure sufficient to cause renal damage also is associated with impairment in olfactory function.