Risk of olfactory dysfunction of the workers in the automobile repair, printing, shoemaking and plating industries in Korea: a cross-sectional study

OBJECTIVES: The present study was performed to investigate the prevalence of olfactory dysfunction in workers exposed to hazardous substances in a variety of occupations in Korea. METHODS: We designed a cross-sectional study. The exposed group (n=296) consisted of Korean workers in the automobile repair, printing, shoemaking and plating industries and was compared with office workers (non-exposed group, n=99). A self-report questionnaire was administered to the subjects for demographic characteristics. In addition, olfactory function was evaluated using the Korean version of Sniffin’s Stick (KVSS) I and II test, which has been reported to be valid and reliable in Korean subjects. KVSS I score ≥7 or KVSS II score ≥30 was classified as normal, KVSS I score <7 or KVSS II score <30 was classified as oflactory dysfunction. The statistical analyses were performed with olfactory dysfunction as a dependent variable to calculate prevalence ratio (PR) of the exposed group. RESULTS: The prevalence of olfactory dysfunction was 21.2% in office, 45.1% in automobile repair, 69.7% in printing and 88.9% in shoemaking and plating workers. The adjusted PR was highest in plating (3.589, 95% CI 1.957 to 6.583), followed by shoemaking (3.136, 95% CI 1.763 to 5.579), printing (2.669, 95% CI 1.610 to 4.424) and automobile repair (1.914, 95% CI 1.105 to 3.317) workers. CONCLUSIONS: In comparison with office workers, the prevalence of olfactory dysfunction and the PR of olfactory dysfunction were very high in the four occupational groups. This finding could be an important basis for establishing the olfactory dysfunction prevention policy for workers who are exposed to hazardous substances or work in high-risk occupations.