text: Project GABRIEL was an investigation to gauge the impact of nuclear fallout resulting from nuclear warfare. The United States Atomic Energy Commission surmised that the radioactive isotope strontium-90 (Sr-90) presented the greatest hazard to life globally, which resulted in the commissioning of Project SUNSHINE: which sought to examine the levels of Sr-90 in human tissues and bones (with a special interest in infants) gathered from around the world.