The author investigated roentgenograms of wrists of babies at about 4 months with healthy appearances when medical examination was conducted in the jurisdiction of Kojiya Health Center. On that occasion, the author obseved relations between incidence of cotyloid deformation of the distal ends of the ulna and the distance between distal ends of the ulna and the proximal ends, of the metacarpal bones biochemical examination of blood, air pollution and ultraviolet ray volume in comparison with various examinations of babies living in the jurisdiction of less air polluted health centers, and especially, conducted study of cotyloid deformation of the distal ends of the ulna. The following are the results of the above studies :
1) Incidence of cotyloid deformation in babies in the heavily air-polluted jurisdiction of the Kojiya Health Center showed 4.5-11.5% (average 7.2%), while in less air-polluted jurisdictions such as Ohme and Ohshima Health Centers showed 4.3-5.2% (avearage 4.7%) .
2) Incase of cotyloid deformation (+), intervals the distal ends of the ulna and the proximal ends of the metacarpal bones were long, which indicated the delay in bone growth.
3) In case of cotyloid deformation (+), alkali-phosphatase in serum showed significantly high value.
4) More sulphurous acid gas and floting particles were found in the jurisdiction of the Kojiya Health Center where high incidence of cotyloid deformation was observed, compared with other jurisdictions.
5) The vrlue of ultraviolet ray in the Kojiya Health Center with high incidence of cotyloid deformation was no more than 1/1.8-1/2.6 of those in the Ohme and Ohshima Health Centers.
In conculsion, it is thinkable that increase in cotyloid deformation of the distal ends of the ulna are caused by defriciency in vitamin D.
