Abstract: A five-year monitoring program was conducted for the radionuclide ⁹⁰Sr in the seawater of the coastal areas of three prefecture-level cities in western Guangdong, namely Zhanjiang, Maoming and Yangjiang, as well as the sea area adjacent to the Yangjiang Nuclear Power Base. The distribution characteristics of this radionuclide were analyzed. The monitoring results show that the activity concentration of ⁹⁰Sr in seawater of the three coastal cities in western Guangdong ranged from 0.25 to 0.98 mBq/L, while that in the sea area around the Yangjiang Nuclear Power Base ranged from <0.15 to 1.2 mBq/L. Spatially, there was no significant difference in the activity concentration of ⁹⁰Sr (P>0.05). Temporally, no significant trend was observed in the activity concentration of ⁹⁰Sr in seawater over the past five years. The activity concentration of ⁹⁰Sr in seawater of western Guangdong was lower than the limit (4 Bq/L) specified in the Sea Water Quality Standard (GB 3097—1997), and showed no significant difference from that in coastal seawater across China.

Key words: seawater in western Guangdong, ⁹⁰Sr, activity concentration, monitoring