The people at risk for developing smell and taste disorders, probably the biggest group would be those suffering from chronic sinusitis, particularly those with nasal polyps. Nasal polyps are inflammatory lining of the nose or nasal mucosa that gets adenomatous, and they act as basically a conductive block. They won't allow odorants or other molecules to get into the olfactory grove area and allow us to perceive how things smell and taste. Additionally, those with allergic rhinitis - allergies, hay fever, and chronically suffering - will have more inflammatory lining of the nose and drainage that would also act as a conductive block. People suffering from choric allergies and chronic sinus disease as probably, as far as number-wise, those that would be most at risk for smell and taste disorders.
