Olfactory disorders induced by cadmium exposure: a clinical study

The evaluation of olfaction is not only widely applied and undeniably valuable in clinical diagnostics but it is also of interest to industrial medicine. It should be borne in mind that in certain workplaces, particularly in the chemical industry, the olfactory receptor has to act as an organ which warns the worker against threatening intoxication, and this is possible only when it functions properly. Cadmium, as a highly toxic metal, found widely in industry and in the environment, is frequently included in the list of chemicals known to cause olfactory impairment. The purpose of this study was to evaluate olfaction in workers occupationally exposed to cadmium. The correlation between olfaction and concentrations of cadmium in urine, blood and in the workplace air as well as employment duration was examined in workers of the "CENTRA" S.A., an electrochemical plant in Poznań. In this plant cadmium-nickel batteries are produced, and there is chronic occupational exposure to cadmium in quantities exceeding maximum allowable concentration (MAC). A group of 73 workers aged 20 to 60 years (42.0 +/- 18.0), employed from 4 to 24 years (12.5 +/- 8.5) were examined. Of the 73 workers who completed the evaluation, 53 people (72.7%) were smokers (10-40 cigarettes per day). In addition to medical history, medical and ENT examinations, blood and urine tests were taken and olfactometry performed. Olfactometry was performed according to Elsberg and Levy's method, modified by Pruszewicz, in which natural coffee as well as aniseed, lemon and mint oils were used. The quantitative and qualitative olfactory disorders were evaluated on the basis of the established odor detection threshold (ODT) and odor identification threshold (OIT). The examinations revealed numerous cases of hyposmia (26.0%) and parosmia (17.8%) and one case of anosmia (1.4%). In the majority of people with olfactory disorders, hypertrophic changes in the nasal mucosa, dependent on the duration of employment, were identified. Statistically significant relationship between olfactory impairment and cadmium concentration in blood, urine and the workplace air was observed. However, such a relationship was not found in regard to the duration of employment. The study indicated the need to carry out routine olfactometries. The results of these examinations could be the ground to perform certain preventive and therapeutic procedures.