Iodine-131 in the thyroids of North American deer and caribou: comparison after nuclear tests

Concentrations of I(131) in the thyroids of deer from Washington, Colorado, and Maryland, and of caribou from Alaska were measured after the resumption of nuclear weapon tests by the U.S.S.R. on 1 September 161. Maximum concentrations occurred nearly 2 months after the first nuclear test and then decreased at an effective half-time of about 15 days. Thyroids from Washington and Colorado deer showed the highest concentrations, thyroids from Alaskan caribou the lowest.