Studies of prevalence of Japanese cedar pollinosis among the residents in a densely cultivated area.

Prevalence studies of Japanese cedar pollinosis in densely planted areas were performed using pollen counts, patient studies, and population surveys with questionnaires. The incidence of pollinosis was increased and appeared to be related to dispersed pollen, which resulted in high immunologic responses. Onset of symptoms was influenced by hereditary factors as well as pollution from automobile exhausts.