RESUMO
The effects of artificial alum bathing and sodium bicarbonate bathing on the surface tension of skin and sweat were examined.<br>Before and after partial bathing in distilled water (control), alum solution, or sodium bicarbonate solution at 40°C for 10 minutes, the critical surface tension of skin was measured in a room in which the ambient temperature was maintained at 23°C and relative humidity at 50%. The mean value of critical surface tension decreased after the alum bathing at concentrations of 10, 100, and 1, 000ppm., but did not change after the control and sodium bicarbonate bathing.<br>Alum solution, sodium bicarbonate solution, or sodium hydroxide solution was added to the sweat collected from the arm skin surface. Its surface tension was then measured in the same room as mentioned above. The mean value of surface tension increased after the sodium bicarbonate preparation and the sodium hydroxide preparation accompanying the increase in the pH value, but did not change after the alum preparation. The surface tension of sweat at pH 7.0 was significantly higher in the sodium bicarbonate preparation than in the sodium hydroxide preparation (p<0.05).<br>These findings suggest that the alum bathing lowers the wettability of the skin surface and that the sodium bicarbonate bathing lowers the surface activity of sweat. It is suggested that both of these bathings change the skin surface condition and cutaneous function.
