S11-6Associations between former exposure to manganese and olfaction in an elderly population: results from the HEINZ NIXDORF recall study

BackgroundOccupational exposure to manganese (Mn) has been associated with parkinsonism. Impairment of olfaction is an early symptom of Parkinson's disease but evidence about olfactory dysfunction in Mn-exposed subjects is missing.ObjectivesThe objective of this study was to evaluate the influence of former occupational Mn exposure on olfaction within the framework of a prospective cohort among elderly men from a German industrial area.MethodsData on job tasks with recognised Mn exposure and on odour identification assessed with Sniffin' sticks were obtained during the second follow-up of the Heinz Nixdorf Recall Study. The study population consisted of 1,195 men aged 55-86 years, 310 of whom ever worked in jobs with Mn exposure. Multiple exposure measures, including at-risk occupations, cumulative airborne Mn exposure, and Mn determined in blood samples (MnB) archived at baseline, were used to estimate Mn effects on olfaction adjusted for covariates.ResultsHaving worked as welder was associated with better olfaction compared with non-exposed blue-collar workers. Cumulative exposure to Mn > 188.8 mu g/m3 years (75th percentile in exposed men) or MnB greater than or equal to 15 mu g/L (German biological reference value for workplace substances) were not associated with impaired olfaction. Next to a strong age effect, current smokers and participants with lower occupational qualification identified less odours.ConclusionsWe found no association of former Mn exposure at relatively low levels with impaired olfaction.