Carbon Monoxide Headquarters





Chronic CO Poisoning:


Komatsu Occupational Study:


SUMMARY AND CONCLUSIONS

"A survey of the health condition of the workers in a factory which had the hazard of carbon monoxide escaping was carried out. The subjects of the survey were 1,074 male workers in the factory. From the subjects, 341 workers were eliminated from the examinations, since they had disease. The remaining so-called healthy 733 workers were subjected to the survey, including the record of subjective symptoms, physical examination and functional tests. For a part of the examinees carbon monoxide hemoglobin (COHb) was estimated. Environmental examination of the factory was also carried out, and according to the variety of the environments, obtained data was divided into three groups and was analyzed.

From the analysis of the data, it was confirmed that by the existence of the carbon monoxide in the respiratory air, various subjective symptoms were developed, and that in the combined attack of carbon monoxide and heat radiation as strong as 32 to 75 C, the toxic effect of carbon monoxide surpassed the influence of heat. It may be said that the survey of the subjective symptoms will be able to give the initial warning of possible poisoning. Physical signs of non-characteristic nature were also frequently found among the workers exposed to carbon monoxide. Vital capacity and strength of the back were decreased among the workers who had the prolonged and repeated exposure to carbon monoxide. These deviated conditions of health may be said that chronic poisoning of carbon monoxide. though it never be accumulated in the body."


Some Summary Points:

  • This was a survey study of 1,074 male workers of an industrial plant.
  • Mean ages of the 4 groups was approximately 32 years of age (no signif. diff.).
  • Group A1 was exposed to 50-250 ppm CO, Group A2 to 60-1370 ppm CO, Group B below 20 ppm CO, and Group C below 10 ppm CO in the course of their normal work.
  • Median COHb saturation in Group A1 was 10-15%, in Group A2 20-25%, in Groups B 1-5%, and Group C 1-5%.
  • Average frequency of health complaints was much higher from Group A1 and A2 members than for Groups B or C.
  • A large variety of subjective health complaints were made by Group A1 and especially Group A2 members. The highest reports, for example, included headache, poor hearing, chest pain, lassitude, fatigue, and forgetfulness.
  • A variety of objective health complaints were made by Group A1 and especially Group A2 members. The highest incidences, for example, included pallor, cardiac enlargement, coldness of extremities, and hyperactive patellar reflex.
  • Average vital capacity was significantly less for members of Group A at any age than for members of Groups B or C.
  • Average back strength was significantly less for members of Group A at ages 30-40 than for same age members of Group C; the difference from members of Group B was very large and signif. over the entire age ranges of the two groups.


    From: Komatsu, F., Honda, S., Murayama, N., Hashimoto, I., and Inoue, T. (1958) The effect of prolonged exposure to carbon monoxide on human health. Med. J. Shinshu Univ., 3 (3), 165-177.



    to Introduction / Study Design


    ...... last changed 02/10/02


    Back to Chronic CO Index