Browsing by Author "Umaly, Ruben C."
Accumulation and tissue distribution of radioiodine (131I) from algal phytoplankton by the freshwater clam Corbicula manilensis MLA Cuvin-Aralar & RC Umaly -
Bulletin of Environmental Contamination and Toxicology, 1991 - Springer VerlagRadioactive wastes discharged from establishments involved in the use of radioisotopes such as nuclear powered industries, tracer research and nuclear medicine are a potential public health hazard. Such wastes contain radionuclides, particularly Iodine-131 (131I), produced in fission with a yield of about 3%. It is a beta emitter (Bmax = 0.61MeV); it also emits gamma photons. It has a short half-life (8.04 d) (Dutton 1975), hence it is difficult to detect unless accumulated by indicator organisms. Radionuclides in waste waters are known to be taken up by molluscs such as mussels (Van der Borght and Van Puymbroeck 1970; Fowler et al. 1975; Hetherington et al. 1976; Helt et al. 1980; and Sombrito et al. 1982), oyster (Romeril 1971; Cranmore and Harrison 1975) and clams (Cuvin and Umaly 1988). This study aims to determine the uptake of 131I from algal phytoplankton (Choroococcus dispersus) fed to the freshwater clam Corbicula manillensis as well as the organ/tissue distribution. The results will be compared with our previous study on 131I uptake from water by the same clams (Cuvin and Umaly 1988).
Uptake and elimination of iodine-131 by the freshwater clam Corbicula manilensis Philippi from water MLA Cuvin & RC Umaly -
Natural and Applied Science Bulletin, 1988 - College of Arts and Sciences, University of the PhilippinesWhole body uptake of Iodine-131 by the freshwater clam, Corbicula manilensis, from contaminated water was followed using NaI scintillation counter. The bioaccumulation factor (BF) exclusive of shell was 5.44. The degree of bioaccumulation of I-131 by the different tissues is as follows: visceral remains > gills > gut > gonads > mantle > muscle > foot. The specific activities of the different tissues corresponded with their BF values. The relative distribution of I-131 in the different tissues was generally proportional to the weight ratio of each tissue. Elimination studies gave the effective half-life, Te0.5, of 4.5 days. Estimation of Te0.5 in the different tissues gave the following values: 12 d (mantle), 3.9 d (gonad and muscle), 3.6 d (gut), 3.4 d (gills), 2.4 d (foot) and 1.9 d (visceral remains).