Assessment of 226 Ra and 228 Ra activity concentration in west coast of India

An investigation on the distribution of 226 Ra and 228 Ra activity concentration in coastal surface sea water from Okha in Gujarat to Ratnagiri in Maharashtra state along the west coast of India was carried out. In-situ pre-concentration technique was used to measure radium isotopes by passing 1,000 L of seawater through MnO 2 impregnated polypropylene filter cartridges at all the locations. 226 Ra was estimated using gamma ray peak of its daughter radionuclides 214 Bi and 214 Pb. 228 Ra was estimated from its daughter 228 Ac. In the coastal waters, 226 Ra and 228 Ra activity concentration were observed to be in the range of 1.5–2.9 and 2.5–8.6 Bq m −3 with a mean of 2.2 and 4.9 Bq m −3 respectively. The activity of 228 Ra was observed to be more than 226 Ra in all the locations. The variation in spatial distribution of the radium isotopes activity concentration and its ratio with respect to location is discussed in the paper. The radioactive database obtained represents reference values for coastal environment of India.