The increased level of plasma and urine erythropoietic stimulatory factor in subjects exposed to high altitude is viewed as one of the early manifestations of the individual's acclimatization to the low oxygen environment. The barometric pressure on the South Polar Plateau ranges from 487 to 525 mm Hg which is the equivalent to that, at 11,000 feet of altitude. Plasma erythropoietin activity on the second, third, and fourth days ranged from 0.05 to 0.43 units of erythropoietin and urine erythropoietin values ranged from 0.32 to 73.3 units. These observations indicate that erythropoietin levels of subjects in this environment are similar to those of individuals subjected to low barometric pressure in other less hostile environments.
Whitcomb WH, Joern AT, Guenter CA, Moore M, Shurley JT, Pierce CM. Effect of the South Polar Plateau on Plasma and Urine Erythropoietin Levels. Arch Intern Med. 1970;125(4):638-645. doi:10.1001/archinte.1970.00310040062005