Taste and Smell Perception among Sewage Workers

Objectives: The study investigated the functioning of the taste and smell senses in workers employed at a sewage treatment plant and waste landfill. Materials and Methods: The study population was divided into three groups: sewage workers (group 1), landfill workers (group 2), and laboratory workers (group 3). Smell sensation was assessed using the Börstein gustometry method and taste sensation the Elsberg-Levy olfactometry method. The examinations were performed before and after working hours. Results: Taste disorders were noted in nearly 20% of subjects in each study group examined before work, and in 50% (group 1), 40% (group 2), 28.4% (group 3) of workers examined after work. As regards the sweet taste, a statistically higher value of the mean taste perception threshold (TPT) could be noted in each group examined before work compared to the control group. This referred also to salty taste in groups 1 and 2 and to bitter taste in groups 1 and 3. In the examinations carried out after work, all average TPTs increased and were statistically significant in relation to the sour and bitter tastes in group 1 and to sour taste in group 2. Smell examinations before and after work showed a statistically higher value of the mean olfactory perception threshold (OPT) for each odour than in the control group. The increase in the mean OPT after work was not statistically significant and did not differ between the groups. Before work, the percentage of workers with smell disorders amounted to 31.5% in the group of sewage workers, 6.3% of laboratory workers and 21.7% of landfill workers. After the working hours, these values increased to 40%, 8% and 38.4%, respectively. Conclusions: The study results indicate a higher risk of smell and taste dysfunctions among workers at a sewage treatment plant and waste landfill. The perception of the sour taste appeared to be most sensitive after short-term exposure but this dysfunction is probably reversible in nature. Other tastes were more sensitive to chronic toxic exposure than the sour taste.