This chapter discusses risk factors for building-related health and comfort complaints in detail. People-based risk factors include personal characteristics, psychosocial phenomenon, and tobacco smoking. The smoking of tobacco products in indoor environments represents a potentially significant environmental exposure and Sick building syndrome (SBS) symptom risk. A variety of personal characteristics have been evaluated as potential contributing factors to SBS symptom prevalence rates in systematic building studies. These include gender, age, marital status, atopic status, and a variety of lifestyle factors such as smoking, alcohol consumption, coffee consumption, regular exercise, use of contact lenses. Hedge et al. in their study on smoking policies, observed no significant differences among buildings with different smoking policies and SBS symptoms. Studies which have attempted to evaluate passive smoking as a risk factor for SBS symptoms have consistently shown a relationship between office workers' perception of exposure to environmental tobacco smoke and increased symptom prevalence.