In this article, an attempt was made to epidemiologically study chronic obstructive diseases of the lung, particularly chronic bronchitis, in Yachiho, a rural village in Nagano Prefecture. The findings reveal that the incidence of chronic bronchitis among inhabitants from 40 to 69 years of age stands at 9.8% for males and 5.7% for females.This incidence is lower than in air-polluted areas but higher than in the non-polluted areas in Japan. The cause to this phenomenon is presumably attributable to the influences of threshing work in paddy fields. The repeated recurrence of Dakkoku Kikanshien (bronchitis for which threshing is responsible) once in a year is associated to a great extent with incidence of chronic bronchitis or its deterioration. Another conceivable factor is the inadequacy of household facillities against the cold weather in this village.
A hematological study has been carried out for 1074 inhabitants aged 40 to 79 years in Ueno village, Gunma Prefecture.(Response rate 81.5%) 1) Anemia (Hb value below 13.0 gram per 100ml) was found in 10.3% of 484 males. 2) Anemia (Hb value below 12.0 gram per 100ml) was highly found in 19.2% of 590 females. 3) The mean values of Hemoglobin concentration, Hematocrit and serum iron in the males were 14.5±1.5 gram per 100ml, 43.4±3.6%, 107.3±39.4 microgram per 100ml and in the females 13.0±1.4 gram per 100ml, 38.8±3.8%, 85.1±30.8 microgram per 100ml. 4) The incidence of the low serum iron level below 70 microgram per 100ml was 16.5% of the males and 32.2% of the females. 5) Mean value of MCHC of females was smaller than that of males. 6) The incidence of Hemoglobin concentration above 12.0 gram per 100ml and serum iron value below 70 microgram per 100 ml was 22.6% of the females examined. 7) Hemoglobin level of 128 males showed significant increase from 13.7±1.4 gram per 100ml in 1968 to 14.8±1.7 gram per 100ml in 1971. These results of highly incidence of anemia and serum iron deficiency in a rural population suggest some implication of their poor environmental factors.