Abstract
The levels of 144Ce, 137Cs, 125Sb, and 90Sr in the open waters of the Great Lakes were measured over the period 1973–81. The levels were found to be very low. 144Ce was detected only up to 1975 after which it dropped below the detection limit. The data indicate that the concentrations of the remaining three radionuclides have decreased with time. 90Sr and 137Cs provide essentially all of the radiological dose from drinking Great Lakes water. The dose equivalant commitments have been calculated from these measurements and found to be well within the Great Lakes Water Quality Agreement's water quality objective for radioactivity.