Smell impairment in workers occupationally exposed to cadmium

ENT and olfactometric examinations were carried out on 73 workers at an electrochemical plant involved in the production of cadmium-nickel batteries, where cadmium fumes were emitted into the workplace. Exposure levels exceeded the maximum allowable concentrations by about 1-2 times. The controls included 43 non-exposed, age- and cigarette-smoking-matched people. The olfactometric tests were carried out by the blast injection method, using natural coffee, aniseed, lemon and mint oils; two threshold measurements were assessed: maximum perceptible odour (MPO) and minimum identifiable odour (MIO). In addition, blood chemistries and urinalysis were carried out. The study revealed the smell lesion in 45.2% of the exposed group vs 4.6% of the controls. A statistically significant correlation between olfactory dysfunction and cadmium concentrations in the blood and urine was found; however, no correlation with the duration of employment was observed. It seems most likely that cigarette smoking, which is a considerable source of cadmium, may intensify this dysfunction, hence heavy smokers should not work in conditions of cadmium exposure.