Comprehensive study of radioactive background in the coastal waters of South China Sea area

The report summarizes the radioactive background measured in the coastal waters of South China Sea during recent three years. The sea area is located at 110 degree-117 degree E and 20 degree-24 degree N. The items included sea water, marine organisms and sediments. The radioactive materials for detection included: gross U, gross β, 238U, 232Th, 226Ra, 40K, 90Sr, 137Cs, 3H, etc.. The contents of radioactive materials in sea water are: gross U, (25.6-40.9) x 10-3 Bq/1; 90Sr, (2.5-4.7) x 10-3 Bq/l; 137Cs, (2.0-4.4) x 10-3 Bq/l; gross β, (55.5-87.5) x 10-3 Bq/l and 3H, 0.33-0.82 Bq/l. The contents of radioactive materials in the sediments are 238U, 51.2-99.7 Bq/kg (dry); 232Th, 38.1-62.1 Bq/kg(dry); 226Ra, 24.3-59.1 Bq/kg(dry); 137Cs, 1.5-2.4 Bq/kg(dry); 40K, 416.3-876.1 Bq/kg(dry) and gross β, 569.2-912.2 Bq/kg(dry).The contents of radioactive materials in the marine organism are 238U, 21.0-99.2 Bq/kg(dry); 232Th, 30.4-111.5 Bq/kg(dry); 226Ra, 7.1-34.7 Bq/kg(dry); 40K, 1069.2-2132.7 Bq/kg(dry); gross β, 1020.0-2492.0 Bq/kg(dry). The radioactive contents in fishes are: 238U, 4.2-12.0 Bq/kg(dry); 232Th, 4.7-57.9 Bq/kg(dry); 226Ra, 1.3-7.1 Bq/kg(dry); 137Cs, 0.4-0.9 Bq/kg(dry)