NATURAL RADIONUCLIDES IN THE WATER OF NARRAGANSETT BAY

The concentrations of radionuclides of the U-Th series (238U, 234Th, 234U, 230Th, 226Ra, 210Pb, 210Po, and 232Th, 228Ra, 228Th) in the water of Narragansett Bay are reported. Analysis of the total, particulate, dissolved and colloidal forms of Th isotopes reveal a consistent removal behavior which is controlled mainly by the particulate matter concentration and the sediment resuspension rate. Half-removal times of Th from solution onto particles range from 1.5 to 15 days, and settling velocities of Th containing particles range generally between 1 and 11 m/day. 210Pb and 210Po concentrations are seasonally dependent, with higher concentrations and slower removal during the early summer (half-removal times from solution onto particles of 1-5 days in winter and up to 2 months in early summer). © 1979.