Prevalence rates and risk factors for allergic symptoms among inhabitants in rural districts.

In order to determine the prevalence of allergic disorders and their association with agricultural factors, a total of 3,717 inhabitants of rural districts in Kumamoto Prefecture were ashed to fill out a questionnaire concerning their allergic status. The results obtained were as follows: One or more items of allergic symptoms were reported by 44% of the subjects. The prevalence rate of each symptom was 8% for respiratory organs, 5% for delayed type of respiratory disorders, 10% for nasal mucosa, 16% for eyes, 16% for urticaria-like derma and 26% for eczema-like derma. Twenty-one percent of the subjects had past histories of allergic diseases such as asthma (3%), nasal allergy (3%), urticaria (6%), contact dermatitis (9%) and so forth. These allergic conditions were seen to be more common among farmers than non-agricultural workers, and also among subjects with allergic constitution than those without such constitution. The highest (62%) prevalence of allergic symptoms was observed in farmers engaged in poultry raising, followed by those engaged in raising flowers (58%), tobacco (58%), cortinellus shiitake (55%), cucumber in plastic greenhouse (53%) and mandarin orange (53%). Among the symptomatic subjects, 12-38% of those with each symptom gave farm work as the direct causative factor for developing the corresponding symptom. Pesticide spraying was the most common agent among those factors.