title: Risk factors for persistent middle-ear effusions.
mesh_terms: D002648:Child; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000150:complications*; D010033:Otitis Media / Q000209:etiology*; D010034:Otitis Media with Effusion / Q000209:etiology*; D012220:Rhinitis / Q000150:complications*; D014028:Tobacco Smoke Pollution
chemical_list: D014028:Tobacco Smoke Pollution