Can not wanting to wear a mask be rational?

I answer the question in the title by analyzing an office environment in which n?N individuals work together in an enclosed area. The ith worker wears his mask for h_i hours per day and this action involves a disutility. His health benefit from wearing a mask depends on how his mask wearing compares with the mask wearing of his co-workers. In this setting, I first compute the symmetric Nash equilibrium that describes the optimal number of hours of mask wearing by each worker. Second, I compute the Pareto efficient level of mask wearing on the part of the n workers. Finally, I explain why there is excessive mask wearing in the Nash equilibrium and then point out that it can indeed be rational to not want to wear a mask.