Radiocaesium activity concentrations in parmelioid lichens within a 60 km radius of the Fukushima Dai-ichi Nuclear Power Plant

Abstract

Radiocaesium activity concentrations ((134)Cs and (137)Cs) were measured in parmelioid lichens collected within the Fukushima Prefecture approximately 2 y after the Fukushima Dai-ichi Nuclear Power Plant accident. A total of 44 samples consisting of nine species were collected at 16 points within a 60 km radius of the Fukushima Dai-ichi Nuclear Power Plant. The activity concentration of (134)Cs ranged from 4.6 to 1000 kBq kg(-1) and for (137)Cs ranged from 7.6 to 1740 kBq kg(-1). A significant positive correlation was found between the (137)Cs activity concentration in lichens and the (137)Cs deposition density on soil (n = 44), based on the calculated Spearman's rank correlation coefficients as r = 0.90 (P < 0.01). The two dominant species, Flavoparmelia caperata (n = 12) and Parmotrema clavuliferum (n = 11), showed strong positive correlations, for which the r values were calculated as 0.92 (P < 0.01) and 0.90 (P < 0.01) respectively. Therefore, Flavoparmelia caperata and Parmotrema clavuliferum are suggested as biomonitoring species for levels of radiocaesium fallout within the Fukushima Prefecture.

Temporal variations of 7Be, 40K, 134Cs and 137Cs in epiphytic lichens (genus Usnea) at the Sakhalin and Kunashir islands after the Fukushima accident

“…from Northern Finland in 2011-2013. Within the same time period (2011-2013), elevated activity concentrations of 137 Cs, ranging from 1096±27 Bq kg -1 to 1740000±20000 Bq kg -1 , were found in several species of epiphytic lichens at Honshu Island in Japan (Table 6) [10,12,13]. The maximum activity concentration of 137 Cs was reported for the foliose lichen Parmotrema clavuliferum from the Fukushima prefecture, and the maximum 137 Cs deposition density on soil for the study area was estimated as 2920 kBq m -2 [10].…”

“…Within the same time period (2011-2013), elevated activity concentrations of 137 Cs, ranging from 1096±27 Bq kg -1 to 1740000±20000 Bq kg -1 , were found in several species of epiphytic lichens at Honshu Island in Japan (Table 6) [10,12,13]. The maximum activity concentration of 137 Cs was reported for the foliose lichen Parmotrema clavuliferum from the Fukushima prefecture, and the maximum 137 Cs deposition density on soil for the study area was estimated as 2920 kBq m -2 [10]. Almost all 137 Cs in the epiphytic lichens in Russia and Japan was apparently derived from the FDNPP [12,24], while in the samples in Finland, the radionuclide origin could be mostly attributed to the Chernobyl accident and the atmospheric nuclear weapons tests conducted in the 1950-1960s.…”

“…The nuclear reactor accident at the Fukushima-Dai-ichi Nuclear Power Plant (FDNPP) in Japan in 2011 (for review see e.g., [9]) has triggered a new wave of research on the lichens ability to intercept and retain the fallout 137 Cs and 134 Cs [10,11,12,13]. Specifically, Dohi et al [10] demonstrated that activity concentrations of 137 Cs in some epiphytic lichens (Parmeliaceae, Ascomycota) were positively correlated with the 137 Cs deposition density on soil. The study by Dohi et al [10] was conducted in Japan at those areas that had been heav-ily contaminated by Fukushima fallout (up to 3000 kBq m -2 of 137 Cs ground deposition).…”

“…Specifically, Dohi et al [10] demonstrated that activity concentrations of 137 Cs in some epiphytic lichens (Parmeliaceae, Ascomycota) were positively correlated with the 137 Cs deposition density on soil. The study by Dohi et al [10] was conducted in Japan at those areas that had been heav-ily contaminated by Fukushima fallout (up to 3000 kBq m -2 of 137 Cs ground deposition). At the same time, some epiphytic (Bryoria sp.…”

Horizontal and vertical distributions of 137Cs in seabed sediments around the river mouth near Fukushima Daiichi Nuclear Power Plant

“…Understanding the features of 137 Cs transport from contaminated mountain forests to coastal sinks is key to the revitalization of marine industries. Therefore, evaluations of forest ecosystems and fluvial and lacustrine environments have been conducted (e.g., Funaki et al 2014;Yamaguchi et al 2014;Kitamura et al 2014;Kurikami et al 2014;Yamada et al 2015;Dohi et al 2015;Niizato et al 2016). 137 Cs distribution in shallow seas, which are major settlement areas for particle-sorbed 137 Cs, is a very important factor when studying 137 Cs transport from contaminated mountain forests to coastal sinks.…”