• Air dose rates measured at the beaches in Fukushima Prefecture were 0.02-0.06 μSv/h. The values are same as the air dose rates before the accident of the Fukushima Daiichi Nuclear Power Station.
• The concentration of radioactive cesium (¹³⁴Cs and ¹³⁷Cs) in seawater was lower than the detection limit.
• Radioactivities were also investigated at beaches in Miyagi Prefecture in 2024. No radioactive cesium was detected.

Reference： Results of radioactivity monitoring survey at swimming beach(in FY2024) (Fukushima Prefecture, The nuclear emergency response headquarters)

Table　Results of radioactivity monitoring survey at swimming beach in Fukushima Prefecture

No.	Beach	City	Classification	Air dose rate at lakeshore or sea shore (µSv/h)				Concentration of radioactive materials in lake water or seawater（Bq/L）
				Observation date	Ground surface (1 cm height)	50 cm height	1 m height	Sampling position	Radioactive cesium		Total β-ray	3H
									134Cs	137Cs
Beach that will be open in this summer
1	Sakkahama	Aizuwakamatsu City	Lake beach	4/22	0.04	0.03	0.03	Surface layer	N.D.	N.D.	-	-
2	Nakadahama			4/22	0.03	0.03	0.03	Surface layer	N.D.	N.D.	-	-
3	Koishigahama			4/22	0.06	0.04	0.04	Surface layer	N.D.	N.D.	-	-
4	Nagahama	Inawashiro Town		4/22	0.06	0.05	0.05	Surface layer	N.D.	N.D.	-	-
5	Tenjinhama			4/22	0.03	0.03	0.03	Surface layer	N.D.	N.D.	-	-
6	Shidahama			4/22	0.05	0.05	0.05	Surface layer	N.D.	N.D.	-	-
7	Joukohama			4/22	0.07	0.06	0.06	Surface layer	N.D.	N.D.	-	-
8	Hamajihama	Koriyama City		4/15	0.03	0.03	0.03	Surface layer	N.D.	N.D.	-	-
9	Yokozawahama			4/15	0.03	0.03	0.04	Surface layer	N.D.	N.D.	-	-
10	Tatehama			4/15	0.04	0.04	0.04	Surface layer	N.D.	N.D.	-	-
11	Funatsuhama			4/15	0.05	0.06	0.05	Surface layer	N.D.	N.D.	-	-
12	Funatsu Park			4/15	0.05	0.04	0.03	Surface layer	N.D.	N.D.	-	-
13	Seishogahama			4/15	0.04	0.03	0.03	Surface layer	N.D.	N.D.	-	-
14	Akiyamahama			4/15	0.03	0.02	0.02	Surface layer	N.D.	N.D.	-	-
15	Tsurushihama	Shinchi Town	Sea beach	4/19	0.03	0.03	0.03	Surface layer	N.D.	N.D.	0.01	N.D.
16	Haragama Obama	Soma City		4/19	0.04	0.04	0.03	Surface layer	N.D.	N.D.	0.01	N.D.
17	Kitaizumi	Minamisoma City		4/19	0.04	0.04	0.04	Surface layer	N.D.	N.D.	0.02	N.D.
18	Ukedo	Namie Town		4/26	0.05	0.05	0.04	Surface layer	N.D.	N.D.	-	-
19	Iwasawa	Naraha Town		4/26	0.04	0.05	0.04	Surface layer	N.D.	N.D.	0.02	N.D.
20	Hisanohama Hattachi	Iwaki City		5/8	0.04	0.04	0.04	Surface layer	N.D.	N.D.	0.03	N.D.
21	Yotsukura			5/8	0.04	0.04	0.04	Surface layer	N.D.	N.D.	0.03	N.D.
22	Shinmaiko beach			5/8	0.06	0.05	0.05	Surface layer	N.D.	N.D.	-	-
23	Usuiso			5/8	0.05	0.04	0.04	Surface layer	N.D.	N.D.	0.03	N.D.
24	Toyoma			5/8	0.05	0.04	0.04	Surface layer	N.D.	N.D.	-	-
25	Nagasaki			5/8	0.04	0.04	0.03	Surface layer	N.D.	N.D.	-	-
26	Obama			5/8	0.04	0.03	0.03	Surface layer	N.D.	N.D.	-	-
27	Nakoso			5/8	0.04	0.04	0.04	Surface layer	N.D.	N.D.	0.03	N.D.

∗N.D; Not detected.

Related articles

• How is the concentration of radioactive cesium in seawater and marine sediment changing?
• Does contamination of estuaries continue due to continuous outflow of radioactive cesium from rivers?
• I heard most of the forests would not be decontaminated. Does cesium remain in the forests?
• In future, what will be radiation exposures to forest workers? Are there any methods to reduce it?
• Does the concentration in river water change before and after forest fire? How did it change by time?

Reference

1. 宮城県, “海水浴場水質測定結果（環境対策課）”, 2024-06-21.
2. 福島県, “令和元年度水浴場の環境放射線モニタリング調査結果”, 2024-06-17.