When negative ions are applied to the body, the calcium and sodium circulating in the body are ionized. This changes the blood pH into an alkaline state and has an overall effect on the body. The normal pH of human arterial blood is approximately 7.40 (normal range is 7.35-7.45), a weak alkaline solution. Blood, which has a pH below 7.35, is considered “acidic”, while blood pH above 7.45 is alkaline. Proper blood pH is essential for optimal health. Negative ions applied to the body are helpful at regulating the blood pH.