Table 2.

Calculated absorbed dose rate in air from direct measurements and soil concentration.

No.a	Municipality	n	Absorbed dose rate in air (nGy h−1)				Ratio of difference
			Direct measurement		Soil concentration
			Mean ± SD	Range	Mean ± SD	Range
1	Lai Chau	6	116 ± 37	87–186	116 ± 35	63–159	1.0
2	Dien Bien	3	88 ± 24	63–110	121 ± 6	115–126	0.7
3	Lao Cai	6	81 ± 27	47–110	110 ± 39	49–155	0.7
4	Ha Giang	10	92 ± 51	44–217	118 ± 45	51–184	0.8
5	Cao Bang	6	60 ± 31	37–119	56 ± 17	27–81	1.1
6	Tuyen Quang	7	78 ± 22	49–120	107 ± 44	53–190	0.7
7	Yen Bai	5	78 ± 38	30–117	94 ± 51	16–152	0.8
8	Bac Kan	7	72 ± 17	47–100	89 ± 24	44–122	0.8
9	Lang Son	10	83 ± 29	43–131	97 ± 30	39–131	0.9
10	Thai Nguyen	6	56 ± 23	38–99	52 ± 32	27–116	1.1
11	Phu Tho	12	78 ± 19	52–113	84 ± 25	49–136	0.9
12	Vinh Phuc	3	89 ± 8	84–98	124 ± 18	108–144	0.7
13	Bac Giang	8	47 ± 10	31–64	49 ± 16	29–70	1.0
14	Quang Ninh	8	84 ± 32	44–144	76 ± 34	39–139	1.1
15	Bac Ninh	2	42 ± 1	41–43	46 ± 1	45–47	0.9
16	Son La	6	60 ± 12	43–75	93 ± 21	78–133	0.7
17	Ha Noi	3	48 ± 8	42–57	79 ± 21	55–95	0.6
18	Hai Duong	3	43 ± 4	39–46	53 ± 13	44–62	0.8
19	Hoa Binh	5	67 ± 17	48–93	75 ± 17	49–95	0.9
20	Hai Phong	2	60 ± 13	50–69	71 ± 2	69–72	0.8
21	Hung Yen	3	52 ± 10	41–61	60 ± 30	25–82	0.9
22	Ha Nam	3	43 ± 8	37–52	73 ± 29	48–104	0.6
23	Thai Binh	3	57 ± 2	56–59	84 ± 9	74–92	0.7
24	Ninh Binh	3	52 ± 4	48–56	86 ± 39	44–120	0.6
25	Nam Dinh	3	45 ± 16	32–63	52 ± 21	33–75	0.9
26	Thanh Hoa	6	69 ± 32	32–104	62 ± 21	38–98	1.1
27	Nghe An	14	78 ± 28	48–154	80 ± 36	30–144	1.0
28	Ha Tinh	4	80 ± 20	57–106	58 ± 18	39–85	1.4
29	Quang Binh	9	73 ± 23	37–98	78 ± 43	26–162	0.9
30	Quang Tri	7	76 ± 24	45–115	78 ± 39	9–116	1.0
31	Thua Thien-Hue	5	86 ± 28	62–131	94 ± 56	16–181	0.9
32	Da Nang	8	101 ± 9	89–119	83 ± 49	30–157	1.2
33	Quang Nam	14	84 ± 22	48–114	81 ± 28	45–140	1.0
34	Quang Ngai	11	116 ± 40	64–175	91 ± 35	50–163	1.3
35	Binh Dinh	11	117 ± 23	85–151	117 ± 58	41–214	1.0
36	Phu Yen	8	81 ± 22	60–114	109 ± 43	65–178	0.7
37	Khanh Hoa	19	72 ± 17	26–98	98 ± 32	49–163	0.7
38	Ninh Thuan	20	83 ± 17	56–121	93 ± 47	18–184	0.9
39	Binh Thuan	18	65 ± 19	28–107	71 ± 32	16–124	0.9
40	Kon Tum	7	79 ± 21	44–101	106 ± 39	63–146	0.7
41	Gia Lai	11	61 ± 23	33–104	98 ± 49	51–205	0.6
42	Dac Lac	11	61 ± 18	38–94	65 ± 47	20–148	0.9
43	Dac Nong	9	37 ± 17	22–73	48 ± 22	14–84	0.8
44	Lam Dong	14	80 ± 39	41–193	80 ± 36	32–151	1.0
45	Binh Phuoc	4	34 ± 19	20–62	66 ± 51	20–136	0.5
46	Dong Nai	15	56 ± 14	27–77	61 ± 17	25–85	0.5
47	Ba Ria-Vung Tau	7	48 ± 11	36–69	44 ± 20	17–73	1.1
48	Tay Ninh	20	50 ± 14	29–80	47 ± 14	14–71	1.1
49	Binh Duong	11	52 ± 10	36–68	56 ± 28	27–104	0.9
50	Ho Chi Minh	11	52 ± 11	29–74	55 ± 17	23–78	0.9
51	Long An	4	75 ± 10	61–85	85 ± 29	59–136	0.9
52	Tien Giang	5	54 ± 9	42–66	49 ± 9	43–59	1.1
53	Ben Tre	4	59 ± 8	51–66	62 ± 7	56–72	0.9
54	Dong Thap	7	61 ± 12	49–80	76 ± 47	43–156	0.8
55	An Giang	3	93 ± 10	81–99	61 ± 23	40–84	1.5
56	Vinh Long	3	59 ± 12	49–73	119 ± 42	73–156	0.5
57	Can Tho	2	48 ± 22	32–63	106 ± 67	58–153	0.5
58	Hau Giang	1	71	ー	85	ー	0.8
59	Tra Vinh	2	54 ± 3	52–56	80 ± 21	56–94	0.7
60	Soc Trang	3	67 ± 13	54–79	75 ± 42	45–123	0.9
61	Bac Lieu	2	74 ± 1	73–74	52 ± 8	46–58	1.4
62	King Giang	7	79 ± 17	54–104	43 ± 44	5–171	1.8
63	Ca Mau	4	66 ± 12	52–81	92 ± 50	47–146	0.7
64	Phu Quoc Island	10	45 ± 22	26–95	22 ± 7	10–31	2.1
All of Vietnam		462	71 ± 28	20–217	77 ± 40	5–214	0.9
Northern Vietnamb		178	73 ± 29	30–217	83 ± 37	9–190	0.9
Southern Vietnamc		284	69 ± 28	20–193	74 ± 41	5–214	0.9

^aThe numbers refer to the designations in Fig. 1a.

^bNorthern Vietnam refers to #1–#31 in Fig. 1a.

^cSouthern Vietnam refers to #32–#64 in Fig. 1a.