Olfactory dysfunction among gas station employees exposed to fuel vapors using digital odor identification testing

Gas station employees are chronically exposed to fuel vapors containing benzene, toluene, ethylbenzene, and xylene (BTEX), and other volatile organic compounds (VOCs), raising occupational concerns about olfactory function. In this cross-sectional study, 116 Brazilian gas station employees (86 men and 30 women; median age, 37.5 years; range, 19–58) completed a questionnaire and underwent objective olfactory assessment with the MultiScent-20 digital odor identification test. Overall, 58.6% had olfactory dysfunction, including 46.6% with hyposmia and 12.1% with anosmia, whereas only 23.3% reported that their work affected their sense of smell. Longer employment duration was associated with lower olfactory scores (Spearman's ρ = −0.41; p < 0.001) and independently increased the odds of dysfunction (odds ratio [OR] = 1.15 per additional year; 95% confidence interval [CI], 1.06–1.26; p = 0.003). These findings support incorporating olfactory assessment into occupational health surveillance for workers chronically exposed to fuel vapors.