PM2.5 exposure and olfactory functions

Abstract

Growing evidence indicates that air pollution can negatively impact cognitive functions. The olfactory system is interesting in this context as it is directly exposed to pollutants and also associated with cognitive functions. The aim of this study was to investigate long- and short-term PM2.5 exposure in association with olfactory functions. Scores from odor tests were obtained from the Betula project–a longitudinal cohort study. Estimates of annual mean PM2.5 concentrations at the participants’ residential address were obtained from a dispersion-model. Daily mean PM2.5 concentrations were obtained from a measuring station close to the test location. We found a positive association between long-term PM2.5 exposure and odor identification, i.e. exposure was associated with a better ability to identify odors. We also found an interaction effect between PM2.5 and age on odor identification. We found no associations between any PM2.5 exposure and odor detection or between short-term PM2.5 exposure and olfactory functions.