Statistical analysis

Values reported were expressed as means ± SEM. Two-way ANOVA was performed using SigmaPlot (version 12.3; Systat Software Inc., San Jose, CA, USA) to determine individual main effects (i.e. Mn exposure effect and H67D effect) and an interaction effect between HFE mutation and olfactory Mn exposure. Post-hoc multiple comparisons were performed by the Holm-Sidak method. Differences were considered significant at p < 0.05.