Abstract
Atmospheric carbon dioxide concentration was measured at several locations in Tokyo, for two weeks, in December, 1995 and 1996, and was found to be increased up to 550 ppm, while it was shown by us to be 450 ppm in December, 1994. These results demonstrate that atmospheric carbon dioxide is steadily increasing at faster rates in Tokyo than we expect, though it has been considered that the atmospheric carbon dioxide is still as much as 350 ppm. Bicarbonate concentration and pH of urine of 13 medical students in Tokyo were also measured for the same period in December of 1995 and 1996, and were found to be significantly increased compared with the values that were reported in the past. Furthermore, urinary bicarbonate and pH were extensively increased, when 4 and 5 students made 3-hour car trip in two different cars with all windows closed, where carbon dioxide was increased up to about 5000 ppm within 1 hour. These results support our previous hypothesis that the increase of atmospheric carbon dioxide may be reflected by the increase of urinary bicarbonate and pH. Our results also suggest that the environmental situation is being seriously aggravated in Tokyo, year by year, in terms of atmospheric carbon dioxide.
