Since cosmic radiation is absorbed by the atmosphere surrounding the Earth, people who live at high altitude receive significantly larger amounts of cosmic radiation exposure than do those who live at low altitude. The glycophorin A-based somatic mutation assay was performed on 36 blood samples from two populations of Tibet inhabitants to determine whether residents at high altitude (4,300 m) accumulate more somatic mutations than do those who live at low altitude (1,500-1,900 m). These two populations differ in estimated cumulative lifetime cosmic radiation dose, with high altitude residents having received a mean of 111 mSv while low altitude residents received a mean of 27 mSv. Results showed no significant difference in peripheral blood variant erythrocyte frequency between these two populations and no difference from results of a previous study on Finnish workers who live at very low altitude (< 500 m).
(C)1997Health Physics Society