Activity Concentrations of Sr-90 and Cs-137 in Seawater and Sediment in the Gulf of Tonkin, Vietnam

Table 2

Radioactivity concentrations of Sr-90 and Cs-137 in surface seawater and sediment in the Gulf of Tonkin.

Sampling location	Sampling date	Radioactivity concentration
		Surface seawater (Bq/m^3)			Sediment (Bq/kg, dry)
		Cs-137	Sr-90	Cs-137/Sr-90	Cs-137	Sr-90	Cs-137/Sr-90
Tra Co	1 Dec. 2018	1.05 ± 0.16	1.08 ± 0.20	0.97	0.97 ± 0.17	0.44 ± 0.08	2.20
	1 Feb. 2019	1.21 ± 0.21	0.80 ± 0.15	1.51	0.44 ± 0.08	0.54 ± 0.13	0.81
	1 June 2019	1.33 ± 0.18	0.78 ± 0.16	1.71	0.51 ± 0.10	0.37 ± 0.09	1.38
	1 Oct. 2019	1.27 ± 0.17	0.85 ± 0.14	1.49	1.05 ± 0.18	0.59 ± 0.14	1.78
	Average ± SD	1.22 ± 0.12	0.88 ± 0.14	1.42 ± 0.31	0.74 ± 0.31	0.49 ± 0.10	1.54 ± 0.59
Bach Long Vi	1 Dec. 2018	1.27 ± 0.22	1.18 ± 0.24	1.08	1.17 ± 0.19	0.48 ± 0.08	2.44
	1 Feb. 2019	1.62 ± 0.25	1.11 ± 0.20	1.46	1.08 ± 0.17	0.41 ± 0.07	2.63
	1 June 2019	1.23 ± 0.13	1.24 ± 0.25	0.99	0.82 ± 0.13	0.54 ± 0.14	1.52
	1 Oct. 2019	1.58 ± 0.23	1.14 ± 0.20	1.39	0.98 ± 0.14	0.52 ± 0.12	1.88
	Average ± SD	1.43 ± 0.20	1.17 ± 0.06	1.22 ± 0.23	1.01 ± 0.15	0.49 ± 0.06	2.12 ± 0.51
Ky Anh	1 Dec. 2018	1.02 ± 0.11	0.81 ± 0.15	1.26	0.88 ± 0.15	0.56 ± 0.13	1.57
	1 Feb. 2019	1.66 ± 0.25	1.19 ± 0.24	1.39	0.69 ± 0.12	0.34 ± 0.08	2.03
	1 June 2019	1.29 ± 0.24	1.13 ± 0.21	1.15	1.00 ± 0.19	0.39 ± 0.08	2.56
	1 Oct. 2019	1.33 ± 0.17	1.23 ± 0.25	1.09	0.67 ± 0.08	0.42 ± 0.09	1.60
	Average ± SD	1.33 ± 0.26	1.09 ± 0.19	1.22 ± 0.14	0.81 ± 0.16	0.43 ± 0.09	1.94 ± 0.47

Measurement uncertainty.