Effects of cattle manure compost application on crop growth and soil-to-crop transfer of cesium in a physically radionuclide-decontaminated field

Resuming crop production in physically decontaminated fields affected by radiocesium (134Cs and 137Cs) releases is crucial for restoring impacted areas. However, surface soil excavation to reduce radiocesium may lead to lower crop yield due to the loss of fertile topsoil. This study aimed to assess the effects of cattle manure compost (CMC) application on soil properties, crop growth, and 137Cs soil-to-crop transfer in a physically decontaminated field and pot experiment. Field trials were conducted during 2018-2022, with CMC (1 and 2 kg m-2 year-1) applied alongside conventional fertilization (CMC1 and CMC2 plots, respectively) in 2018-2019 and conventional fertilization alone in 2020-2022. Additionally, a pot experiment was used to evaluate the impact of CMC application in soil (1 kg m-2 year-1 for 5 years) on 137Cs transfer. In the field trial during 2018-2019, CMC1 and CMC2 plots exhibited higher soybean shoot dry weight (DW) compared with plots receiving conventional fertilization and additional K fertilizer (+K2O). CMC application also improved soil nutrient content. The transfer factor of 137Cs (TF-137Cs: plant 137Cs activity concentration/soil 137Cs activity concentration) followed the order CMC2 < CMC1 ≈ +K2O < conventional fertilization only (CF) and was negatively correlated with soil exchangeable K (Ex-K). During 2020-2022, when all plots received conventional fertilization alone, grain yields were higher in CMC1 and CMC2 plots than in the +K2O plot, with the lowest TF-137Cs in CMC2 plot followed by CMC1, +K2O, and CF plots. The pot experiment confirmed that CMC soil had a lower TF-137Cs and higher plant DW compared with CF soil with the same Ex-K level. Additionally, the soil exchangeable 137Cs (Ex-137Cs) level was significantly lower in CMC soil than CF soil. These findings demonstrate the potential of CMC application to improve crop growth and reduce 137Cs transfer in physically decontaminated fields.

Transfer of 137Cs and 90Sr from soil-to-potato: Interpretation of the association from global fallout in Aomori to accidental release in Fukushima and Chornobyl

Ceasium-137 and 90Sr are major artificial radionuclides that have been released into the environment. Soil-to-plant transfer of radionuclides is an important route to food contamination. The radionuclide activity concentrations in crops must be quantitatively predicted for estimating the internal radiation doses from food ingestion. In this study, soil and potato samples were collected from three study sites contaminated with different sources of 137Cs and 90Sr: Aomori Prefecture (global fallout) and two accidental release areas (Fukushima Prefecture and the Chornobyl exclusion zone). The 137Cs activity concentrations in the soil and potato samples widely ranged from 1.0 to 250,000 and from 0.048 to 200,000 Bq kg-1 dry weight, respectively. The soil-to-potato transfer factor of 137Cs also ranged widely (0.0015-1.1) and decreased with increasing concentration of exchangeable K. Meanwhile, the activity concentrations of 90Sr in the soil and potato samples were 0.50-64,000 and 0.027-18,000 Bq kg-1 dry weight respectively, and the soil-to-potato transfer factor of 90Sr was 0.023-0.74, decreasing with increasing concentration of exchangeable Ca. The specific activity ratios of 137Cs/Cs and 90Sr/Sr in the exchangeable fraction were similar to those in potatoes, with a factor of 3 in the ±95 % confidence intervals over six orders of magnitude and a factor of 2 in the ±95 % confidence intervals over five orders of magnitude, respectively. According to the data, the accuracy of predicting the activity concentrations of 137Cs and 90Sr in potatoes can be improved by applying the specific activity ratios of 137Cs/Cs and 90Sr/Sr in the exchangeable fraction. This approach accounts for variable factors such as the effects of K and Ca fertilization and soil characteristics. It also emphasizes the benefit of determining the stable Cs and Sr concentrations in potatoes and other crops prior to possible future contamination.

Rapid survey of de novo mutations in naturally growing tree species following the March 2011 disaster in Fukushima: The effect of low-dose-rate radiation

The impact of low-dose-rate radiation on genetics is largely unknown, particularly in natural environments. The Fukushima Dai-ich Nuclear Power Plant disaster resulted in the creation of contaminated natural lands. In this study, de novo mutations (DNMs) in germ line cells were surveyed from double-digest RADseq fragments in Japanese cedar and flowering cherry trees exposed to ambient dose rates ranging from 0.08 to 6.86 μGy h^-1. These two species are among the most widely cultivated Japanese gymnosperm and angiosperm trees for forestry and horticultural purpose, respectively. For Japanese flowering cherry, open crossings were performed to produce seedlings, and only two candidate DNMs were detected from uncontaminated area. For Japanese cedar, the haploid megagametophytes were used as next generation samples. The use of megagametophytes from open crossing for next generation mutation screening had many advantages such as reducing exposure to radiation in contaminated areas because artificial crossings are not needed and the ease of data analysis owing to the haploid nature of megagametophytes. A direct comparison of the nucleotide sequences of parents and megagametophytes revealed an average of 1.4 candidate DNMs per megagametophyte sample (range: 0-40) after filtering procedures were optimized based on the validation of DNMs via Sanger sequencing. There was no relationship between the observed mutations and the ambient dose rate in the growing area or the concentration of ¹³⁷Cs in cedar branches. The present results also suggest that mutation rates differ among lineages and that the growing environment has a relatively large influence on these mutation rates. These results suggested there was no significant increase in the mutation rate of the germplasm of Japanese cedar and flowering cherry trees growing in the contaminated areas.

ACTIVITY CONCENTRATIONS OF RADIOCAESIUM, 90SR AND 129I IN AGRICULTURAL CROPS COLLECTED FROM FUKUSHIMA AND REFERENCE AREAS IN JAPAN, AND INTERNAL RADIATION DOSES

Significant quantities of radionuclides were released into the environment due to the 2011 TEPCO's FDNPS accident. Radiocaesium is the most important radionuclide for assessment of radiation dose, and small amounts of 90Sr and very long-lived radionuclide of 129I were also released into the environment. Spinach, potato and brown rice were collected from Fukushima, neighboring prefectures and reference areas of negligible deposition in 2018 and 2019. The activity concentration of 137Cs in crops in Hamadori (coastal side) was relatively higher than other areas. The activity concentration of 90Sr in the crops showed a similar range among four areas in Fukushima, and they were similar level of those collected throughout Japan. The activity concentration of 129I in the crops collected from Hamadori was higher than other Fukushima areas. However, the activity ratio of 129I/137Cs was lower by five to seven orders of magnitude. Internal radiation doses of radiocaesium for adult males from ingestion of local crops collected from Hamadori were 0.0046 mSv, and that of 129I were 0.00000045 mSv in 2019.

SOIL-SOIL SOLUTION DISTRIBUTION COEFFICIENT OF RADIOIODINE IN SURFACE SOILS AROUND SPENT NUCLEAR FUEL REPROCESSING PLANT IN ROKKASHO, JAPAN

The soil-soil solution distribution coefficient (Kd) of radioiodine in soil samples with various total carbon (TC) contents was measured in a batch sorption experiment using 125I tracer spiked as I-. The log values of Kd-125I and TC concentration in low-TC soils (< 10g kg-1) were positively correlated, whereas those of Kd-125I in TC rich soils (> 10 g kg-1) and dissolved organic carbon (DOC) in liquid phase were negatively correlated. The proportion of 125I in the < 3 kDa fraction in the liquid phase is negatively correlated with the log of DOC, implying that 125I is primarily combined with high-molecular-weight organic matter in soil solutions rich in DOC. The results suggest that Kd-125I in soil with high soil organic material (SOM) content is governed by DOC via the combination of 125I and DOC. In contrast, Kd-125I in soils with a low SOM content was governed by SOM because the anion exchange capacity of SOM was vital for the sorption of 125I-.

Estimation of rooting depth of 137Cs uptake by plants

Understanding the soil-to-plant transfer process of ¹³⁷Cs is essential for predicting the contamination levels of plants in contaminated areas. The rooting depth is considered one of the key factors explaining the difference in the activity concentration of ¹³⁷Cs in different plant species. In this study, the distributions of ¹³⁷Cs and ¹³³Cs in soils and plants were investigated, and the plants' rooting depth of ¹³⁷Cs uptake was estimated using the ¹³⁷Cs/¹³³Cs ratios in exchangeable fractions of soils and biological samples. The results showed that different plant species accumulate different levels of ¹³⁷Cs and ¹³³Cs. The ¹³⁷Cs/¹³³Cs ratios were fairly constant in plants of the same species. The average ¹³⁷Cs/¹³³Cs ratios in bamboo grasses and ferns were 0.015 ± 0.009 (n = 5) and 0.13 ± 0.04 Bq ng^-1 (n = 10) in Yamakiya, respectively. The percentage of ¹³⁷Cs in the exchangeable fraction of the uppermost soil layer was lower than that in the deeper soil layers. The activity concentrations of ¹³⁷Cs in the soil profiles decreased sharply with depth, whereas the depth distributions of ¹³³Cs were uniform. Therefore, the ¹³⁷Cs/¹³³Cs ratios were driven mainly by the ¹³⁷Cs activity concentrations in soil. The plants' rooting depths of ¹³⁷Cs uptake were estimated on the basis of the relationships between the averaged ¹³⁷Cs/¹³³Cs ratio in the soil layer and the ¹³⁷Cs/¹³³Cs ratio in the plant. The results indicate that the deeper-rooted species such as bamboo grasses have a lower accumulation of ¹³⁷Cs than the superficial-rooting species such as ferns. The soil-to-plant transfer factors would be determined using rooting depth by calculating the averaged activity concentration of ¹³⁷Cs within the estimated rooting depth.

Accumulation of 137Cs in aggregated organomineral assemblage in pasture soils 8 years after the accident at the Fukushima Daiichi nuclear power plant

Despite the presence of minerals that allow Cs fixation in soils, ¹³⁷Cs remains available to crops for several years after its deposition, particularly in pasture soils. Larger amounts of organic matter derived from herbage residues are accumulated in pasture soils than in tilled farmland soils. As the above-ground part of herbage crops initially received airborne ¹³⁷Cs during the accident at Fukushima Daiich nuclear power plant (FDNPP), the organic matter originated from the contaminated herbage should play an important role in the fate of ¹³⁷Cs in soils. To evaluate the role of organic matter on ¹³⁷Cs distribution between potentially mobile and immobile fractions, we compared the distribution of ¹³⁷Cs and stable ¹³³Cs, which are differently associated with organic matter, by sequential extraction and density fractionation. Soil samples were collected 8 years after the accident from Andosols in pasture fields located about 160 km southwest of FDNPP. More than 90% of ¹³⁷Cs was not extracted even after oxidative digestion of organic matter, suggesting that most ¹³⁷Cs was strongly associated with soil minerals. Density fractionation results showed that the ¹³⁷Cs/¹³³Cs ratio was highest in the density fraction of 1.6-1.8 g cm^-3, in which organic matter -including fragmented and decomposed plant detritus -was associated with minerals. Mineral-free organic matter, mostly composed of fresh plant detritus (<1.6 g cm^-3), had a higher ¹³⁷Cs/¹³³Cs ratio than that of crops harvested in the same year of soil sampling. Thus, the transfer of ¹³⁷Cs from soil to plants decreased with cultivation cycles. Our results demonstrate that plant-available ¹³⁷Cs in pasture soil decreased with aging time, not only through increased ¹³⁷Cs fixation in mineral-dominated fractions but also through its physical sequestration in aggregates.

Development of In Vitro Endothelialised Stents - Review

Endovascular treatment is prevalent as a primary treatment for coronary and peripheral arterial diseases. Although the introduction of drug-eluting stents (DES) dramatically reduced the risk of in-stent restenosis, stent thrombosis persists as an issue. Notwithstanding improvements in newer generation DES, they are yet to address the urgent clinical need to abolish the late stent complications that result from in-stent restenosis and are associated with late thrombus formation. These often lead to acute coronary syndromes with high mortality in coronary artery disease and acute limb ischemia with a high risk of limb amputation in peripheral arterial disease. Recently, a significant amount of research has focused on alternative solutions to improve stent biocompatibility by using tissue engineering. There are two types of tissue engineering endothelialisation methods: in vitro and in vivo. To date, commercially available in vivo endothelialised stents have failed to demonstrate antithrombotic or anti-stenosis efficacy in clinical trials. In contrast, the in vitro endothelialisation methods exhibit the advantage of monitoring cell type and growth prior to implantation, enabling better quality control. The present review discusses tissue-engineered candidate stents constructed by distinct in vitro endothelialisation approaches, with a particular focus on fabrication processes, including cell source selection, stent material composition, stent surface modifications, efficacy and safety evidence from in vitro and in vivo studies, and future directions.

Radiation dose rate to Japanese cedar and plants collected from Okuma, Fukushima Prefecture

After the 2011 Fukushima Dai-ichi Nuclear Power Station (FDNPS) accident, wild populations of animals and plants living in the evacuation zone received additional ionizing radiation of both internal and external radiation doses. Morphological abnormalities of pine and fir trees near the FDNPS were reported. In order to evaluate dose-effect relationships, it is necessary to quantify the radiation doses to trees and plants. In this study, the internal and external dose rates to Japanese cedar and plants collected at three sites in Okuma, approximately 4 km southwest of FDNPS were estimated applying the ERICA Assessment Tool. The activity concentrations of ¹³⁴Cs and ¹³⁷Cs in soils, cedar trunks, and plants were determined. The total dose rates to cedar ranged from 2.2 ± 1.2 to 6.1 ± 2.2 μGy h^-1. These rates were within the derived consideration reference levels (DCRLs) reported by ICRP 108 as 4-40 μGy h^-1 for pine trees. The highest estimate for plants was 7.1 ± 2.7 μGy h^-1, much smaller than the DCRLs reported for grasses and herbs (40-400 μGy h^-1). On average, the internal radiation dose rates to cedars at the two sites accounted for 5% and 29% of the external dose rates, respectively, while the value in another site was only 0.4% for cedar. This was attributed to differences in the crown area between the three sites. The trunk diameter of cedars shows a positive correlation with the ratio of internal to external radiation dose rates. It indicates that the total dose rate to cedars is easily estimated with the soil radiocaesium inventory and trunk diameter. The internal radiation dose rate to the plant varied depending on the plant species. This variation was considerably large in plants due to the presence of two species, including Solidago altissima and Artemisia indica var. maximowiczii.

Radiocaesium in the environment of Fukushima

It has been 10 years since the accident at Fukushima Daiichi nuclear power plant in 2011. Large quantities of ¹³¹I, ¹³⁴Cs, and ¹³⁷Cs were released into the environment, and 80% of ¹³⁷Cs still remains. In addition to the decrease by attenuation, the transfer of ¹³⁷Cs to plants, animals, and humans is decreasing due to movement and changing fractions with elapsed time. The activity concentration of ¹³⁷Cs in the atmosphere has decreased drastically, and the internal radiation dose due to inhalation is negligible. The activity concentration of ¹³⁷Cs in agricultural plants is decreasing due to decontamination of soil, application of potassium, and lower levels in irrigation water. The activity concentration of ¹³⁷Cs in wild animals is decreasing, and shows seasonal variation in wild boars. The activity concentration of ¹³⁷Cs in offshore seawater has decreased to 0.01 Bq l^-1. Therefore, the radiation dose is <1 mSv of the additional radiation dose.

Differentiating Fukushima and Nagasaki plutonium from global fallout using 241Pu/239Pu atom ratios: Pu vs. Cs uptake and dose to biota

Plutonium (Pu) has been released in Japan by two very different types of nuclear events - the 2011 Fukushima accident and the 1945 detonation of a Pu-core weapon at Nagasaki. Here we report on the use of Accelerator Mass Spectrometry (AMS) methods to distinguish the FDNPP-accident and Nagasaki-detonation Pu from worldwide fallout in soils and biota. The FDNPP-Pu was distinct in local environmental samples through the use of highly sensitive ²⁴¹Pu/²³⁹Pu atom ratios. In contrast, other typically-used Pu measures (²⁴⁰Pu/²³⁹Pu atom ratios, activity concentrations) did not distinguish the FDNPP Pu from background in most 2016 environmental samples. Results indicate the accident contributed new Pu of ~0.4%-2% in the 0-5 cm soils, ~0.3%-3% in earthworms, and ~1%-10% in wild boar near the FDNPP. The uptake of Pu in the boar appears to be relatively uninfluenced by the glassy particle forms of fallout near the FDNPP, whereas the ^134,137Cs uptake appears to be highly influenced. Near Nagasaki, the lasting legacy of Pu is greater with high percentages of Pu sourced from the 1945 detonation (~93% soils, ~88% earthworm, ~96% boar). The Pu at Nagasaki contrasts with that from the FDNPP in having proportionately higher ²³⁹Pu and was distinguished by both ²⁴⁰Pu/²³⁹Pu and ²⁴¹Pu/²³⁹Pu atom ratios. However, compared with the contamination near the Chernobyl accident site, the Pu amounts at all study sites in Japan are orders of magnitude lower. The dose rates from Pu to organisms in the FDNPP and Nagasaki areas, as well as to human consumers of wild boar meat, have been only slightly elevated above background. Our data demonstrate the greater sensitivity of ²⁴¹Pu/²³⁹Pu atom ratios in tracing Pu from nuclear releases and suggest that the Nagasaki-detonation Pu will be distinguishable in the environment for much longer than the FDNPP-accident Pu.

Stimulatory effect of insulin on H+-ATPase in the proximal tubule via the Akt/mTORC2 pathway

Purpose

Acid-base transport in renal proximal tubules (PTs) is mainly sodium-dependent and conducted in coordination by the apical Na+/H+ exchanger (NHE3), vacuolar H+-adenosine triphosphatase (V-ATPase), and the basolateral Na+/HCO3- cotransporter. V-ATPase on PTs is well-known to play an important role in proton excretion. Recently we reported a stimulatory effect of insulin on these transporters. However, it is unclear whether insulin is involved in acid-base balance in PTs. Thus, we assessed the role of insulin in acid-base balance in PTs.

Methods

V-ATPase activity was evaluated using freshly isolated PTs obtained from mice, and specific inhibitors were then used to assess the signaling pathways involved in the observed effects.

Results

V-ATPase activity in PTs was markedly enhanced by insulin, and its activation was completely inhibited by bafilomycin (a V-ATPase-specific inhibitor), Akt inhibitor VIII, and PP242 (an mTORC1/2 inhibitor), but not by rapamycin (an mTORC1 inhibitor). V-ATPase activity was stimulated by 1 nm insulin by approximately 20% above baseline, which was completely suppressed by Akt1/2 inhibitor VIII. PP242 completely suppressed the insulin-mediated V-ATPase stimulation in mouse PTs, whereas rapamycin failed to influence the effect of insulin. Insulin-induced Akt phosphorylation in the mouse renal cortex was completely suppressed by Akt1/2 inhibitor VIII and PP242, but not by rapamycin.

Conclusion

Our results indicate that stimulation of V-ATPase activity by insulin in PTs is mediated via the Akt2/mTORC2 pathway. These results reveal the mechanism underlying the complex signaling in PT acid-base balance, providing treatment targets for renal disease.

Effects of organic amendments on the natural attenuation of radiocesium transferability in grassland soils with high potassium fertility

Organic amendments affect the behavior of radiocesium in soil-plant systems in a complex way; they can inhibit radiocesium fixation by clay minerals by blocking selective sorption sites, whereas K supplied to the soil solution by amendments can reduce Cs uptake by plant roots. Here, we investigated the influence of inorganic and organic amendments on the transferability of radiocesium from soil to grass seedling in a humus-rich Andosol with high exchangeable K content. Soil samples were spiked with a¹³⁷Cs tracer, treated with N, N-P-K, compost (cattle manure using rice straw), or no amendment (control soil), and subjected to repeated two-week wetting and air-drying treatments for one year in an artificial climate chamber. Small-scale cultivations of orchard grass were performed four times during the experimental period to assess temporal changes of availability of ¹³⁷Cs in the soils. The ¹³⁷Cs transfer factor (TF), defined as the ¹³⁷Cs concentration in the plant divided by that in the soil, decreased with time in the control soil. The soil treated with compost showed higher TFs than the control soil in each cultivation and a slower attenuation of ¹³⁷Cs transferability. By comparing the extractability of ¹³⁷Cs, NH₄⁺, and K⁺ with the observed TFs, we show that K released from the compost was not effective in reducing root uptake of ¹³⁷Cs, but enhanced ¹³⁷Cs desorption from the soil under K-rich conditions. This result suggests that organic amendment is ineffective in reducing root uptake of radiocesium under high exchangeable K concentrations, and may instead enhance the long-term availability of radiocesium in soils.

Relationship between radiocaesium in muscle and physicochemical fractions of radiocaesium in the stomach of wild boar

After the accident at the TEPCO Fukushima Daiichi Nuclear Power Plant in 2011, it became important to study radiation dynamics, assess internal radiation exposure and specify factors affecting radionuclide variation in wildlife. Therefore, it is necessary to investigate which physicochemical fractions of radiocaesium (¹³⁷Cs) are absorbed from ingested material in species with high activity concentrations of ¹³⁷Cs, such as wild boar. This study analysed the physicochemical fractions of ¹³⁷Cs in the stomach contents of wild boar to evaluate the transfer from ingested food to muscle. The ¹³⁷Cs activity concentration in muscle showed a significantly positive relationship with the ¹³⁷Cs activity concentration in the exchangeable fraction, and the sum of the ¹³⁷Cs activity concentrations in the exchangeable and bound to organic matter fractions. Seasonal variations were also found in the ¹³⁷Cs activity concentration in the exchangeable fraction, and the sum of the ¹³⁷Cs activity concentrations in the exchangeable and bound to organic matter fractions. These findings suggest that the proportions of the physicochemical fractions of ¹³⁷Cs in the exchangeable and bound to organic matter fractions in the stomach contents are important factors affecting the increases and seasonal dynamics of the activity concentrations of ¹³⁷Cs in wild boar muscle.

Dynamics of Strontium and geochemically correlated elements in soil during washing remediation with eco-complaint chelators

In the study, the dynamics of Sr²⁺ and geochemically correlated elements (Ca²⁺, Ba²⁺, and Y³⁺) in soil with chelators in the mix (soil to chelator ratio, 1:10; matrix, H₂O) were assessed to understand chemical-induced washing remediation of radiogenic waste solids. Specifically, EDTA (2,2',2″,2‴-(ethane-1,2-diyldinitrilo)tetraacetic acid), EDDS (2-[2-(1,2-dicarboxyethylamino)ethylamino]butanedioic acid), GLDA (2-[bis(carboxymethyl)amino]pentanedioic acid), and HIDS (2-(1,2-dicarboxyethylamino)-3-hydroxy-butanedioic acid) are chelators that are used as extractants. The effect of solution pH on chelator-induced extractions of the target elements (t-Es: Sr²⁺, Ca²⁺, Ba²⁺, or Y³⁺) from soil and stability constants of the t-Es complexes with chelators were used to explain the trends and magnitudes in interactions. Pre- and post-extractive solid-phase speciation was used to define the extent of the competence of each chelator in persuading dissolution of t-Es in the soil. The effects of ultrasonic energy, admixtures of biodegradable chelators, and excess chelators in solution (1:20) were also analyzed on the extractive removal of t-Es from soil. The results indicate that the Sr²⁺ removal with biodegradable chelators significantly exceeded (approximately 70%) when compared to that of environmentally-persistent EDTA at lower solution pHs and a higher soil to chelator ratio (GLDA > HIDS > EDDS ≈ EDTA). However, the extraction of the geochemically related element was significantly lower.

SPECIATION OF IODINE IN SOIL SOLUTION IN FOREST AND GRASSLAND SOILS IN ROKKASHO, JAPAN

The behaviour of I in soil depends on its chemical form in soil solution. Stable I (127I) in the soil solution under actual soil conditions was investigated as a natural analogue of long-lived radioiodine (129I). Soil samples were collected at 5-cm depth intervals down to 20 cm from forests and grasslands in Rokkasho, where the Japanese first commercial nuclear fuel reprocessing plant is located, and the soil solution was extracted by centrifugation. Almost half of total I in the soil solution was iodide, and the other half was dissolved organic I (DOI), with iodate under the detection limit. The proportion of DOI in total I at 0-5 cm depth was larger than the proportions at 5-20 cm depth. The concentration of DOI was positively correlated with that of DOC in the soil solution, suggesting that the behaviour of DOI in the surface soil is affected by labile organic matter dynamics.

Vertical distribution of 129I and radiocesium in forest soil collected near the Fukushima Daiichi Nuclear Power Plant boundary

Three soil core samples were collected from a forest located about 1.1 km south of the Fukushima Daiichi Nuclear Power Plant (FDNPP) boundary in 2017, and the vertical profiles of ¹²⁹I from the FDNPP accident were determined by the combination of TMAH (tetramethyl ammonium hydroxide) extraction and ICP-MS/MS analysis. The humus layer above the soil layer was heavily contaminated with ¹³⁴Cs (1983-5985 Bq g^-1) and ¹³⁷Cs (1947-5902 Bq g^-1) (decay-corrected to March 11, 2011). The ¹²⁹I activity concentrations decreased sharply with the soil depth, from 1894 to 34.1, from 9384 to 78.9, and from 2536 to 51.3 mBq kg^-1, for the three sites. Downward migration of ¹²⁹I was slightly faster than the one of ¹³⁴Cs. In addition, the cumulative ¹²⁹I inventories were observed to be 43.4 ± 1.0, 71.7 ± 1.8, and 56.5 ± 1.8 Bq m^-2, respectively. Subsequently, the cumulative ¹³¹I inventories were estimated to be 1.76 ± 0.06, 2.90 ± 0.11, and 2.28 ± 0.10 GBq m^-2 (decay-corrected to March 11, 2011), respectively. Finally, the total atmospheric deposition of ¹²⁹I on the land of Japan due to the FDNPP accident was estimated to be around 1.09-1.71 kg (7.11-11.2 GBq).

Phytoavailability of 137Cs and stable Cs in soils from different parent materials in Fukushima, Japan

Weathered micaceous minerals (micas) are able to release potassium ion (K⁺) and fix caesium-137 (¹³⁷Cs), both of which reduce soil-to-plant transfer of ¹³⁷Cs. Among micas, trioctahedral micas such as biotite is expected to have a stronger ability to supply nonexchangeable K⁺ and a higher amount of Cs fixation sites than dioctahedral micas such as illite. Although biotite is predominant in granitic soils (G soils), illite is mainly dominant in sedimentary rock soils (S soils). Therefore, we hypothesized that G soils have a lower ¹³⁷Cs transfer risk than S soils because of this difference in mineralogy. The objective of the present study was to determine the transfer factor (TF) of ¹³⁷Cs and stable Cs (SCs) and to elucidate the determinant factors of TFs for G and S soils in Fukushima, Japan. Pot experiments were carried out with rice (Oryza sativa L. cv. Hokuriku 193) in G and S soils to determine the TF of ¹³⁷Cs (TF-¹³⁷Cs) and stable Cs (TF-SCs) under K-deficient conditions. TF-¹³⁷Cs and TF-SCs were highly correlated, and both were significantly lower for G soils than for S soils. Higher TF values were shown for soils with lower amounts of exchangeable and nonexchangeable K or with higher percentages of exchangeable ¹³⁷Cs (ex¹³⁷Cs). The percentage of ex¹³⁷Cs was negatively correlated with the amount of Cs fixation sites, represented by the radiocaesium interception potential. Thus, we concluded that smaller TF values for G soils were caused by a stronger ability to supply nonexchangeable K⁺ and a higher amount of Cs fixation sites. These findings will contribute to the establishment of soil screening techniques based on ¹³⁷Cs transfer risk in Fukushima prefecture.

The transfer of fallout plutonium from paddy soil to rice: A field study in Japan

Reported transfer factor (TF) values of Pu from paddy soil to rice are rather scarce, despite the radiotoxicity of Pu and the irreplaceable role of rice in Asian peoples' diets. Here, we conducted a field study to investigate the transfer of global fallout Pu from paddy soil to rice grain (hulled rice) in Japan. The ²⁴⁰Pu/²³⁹Pu atomic ratios in two rice grain samples out of 16 samples were determined and the ratios corresponded well with the global fallout value. The soil-to-rice TF_Pu in 12 Japanese prefectures ranged from 4.5 × 10^-6 to 1.2 × 10^-4 with a geometric mean of 3.3 × 10^-5. The TFs of rice obtained in this study were compatible to the TFs for the broad heading "cereals" compiled in the IAEA Technical Report Series No. 472. Weak correlations were found between the TF and the investigated soil characteristics such as soil pH and loss on ignition. Regarding the TFs for cerium (Ce) and thorium (Th) which are commonly considered as Pu analogues, we observed no significant correlations between the log(TF_Pu) and log(TF_Ce) or log(TF_Pu) and log(TF_Th). On the other hand, interestingly, a significantly positive correlation (r = 0.795, p < 0.001) was observed between log(TF_Pu) and log(TF_U). In view of the observed similarity of TF values for U and Pu from soil to rice, we thought that using the easy-to-measure TF_U to estimate TF_Pu from soil to rice might be suggested although the mechanism was unclear.

Changes in the Soil to Brown Rice Concentration Ratio of Radiocaesium before and after the Fukushima Daiichi Nuclear Power Plant Accident in 2011

Radiocaesium (^RCs) mobility in soil is initially relatively high when the nuclide first comes into contact with soil, after which the mobile fraction decreases with time due to ^RCs fixation to soil particles (aging effect). Consequently, the ^RCs activity concentration in plants grown in soil was expected to decrease with time after the Fukushima Daiichi nuclear power plant accident in 2011. In this study, we collated data on concentration ratios (CR) of ^RCs between brown rice grain and paddy soil and compared CR values reported for periods before and after the accident. For this purpose, soil and rice data were collected after the accident specifically from paddy fields that did not have additional potassium fertilizer added (for remediation purposes). The geometric mean rice/soil CR of ^RCs for all types of soil was 1.2 × 10^-2 in 2011 ( n = 62) and by 2013 the value had declined to 3.5 × 10^-3 ( n = 32), which was similar to that for 1995-2007 of 3.4 × 10^-3 ( n = 120). The comparison suggests that the mean soil-to-rice grain concentration ratio had returned to that prevailing before the accident after less than three years. It was also confirmed that CR values for rice sampled from paddy fields were lower than those obtained from pot experiments.

The 137Cs activity concentration of suspended and dissolved fractions in irrigation waters collected from the 80 km zone around TEPCO's Fukushima Daiichi Nuclear Power Station

Fifty-four samples of irrigation water were collected in 2014 from agricultural ponds, rivers, and dams within the 80 km zone around TEPCO's Fukushima Daiichi Nuclear Power Station (FDNPS). The samples were filtered with a 0.45 μm pore-size membrane filter to produce suspended and dissolved fractions. The ¹³⁷Cs activity concentration of the suspended fraction varied from 1.5 to 300 Bq g^-1 dry weight and was significantly higher than that in the soil around each sampling site. The range of ¹³⁷Cs activity concentrations in the dissolved fraction varied over three orders of magnitude at 0.0075-6.7 Bq l^-1, which was a larger range than that of the suspended fraction; the higher values for samples were from within the 20 km zone. In the dissolved fraction 87 ± 9% of the ¹³⁷Cs (n = 37) was in a monovalent cationic form (Cs⁺) and therefore potentially mobile. The distribution coefficient (Kd) ranged from 4100 to 2,100,000; the geometric mean value (110,000) was higher than that reported by the IAEA (2010). The geometric mean Kd of samples collected from the 20 km zone was 61,000 (n = 27), which was significantly lower than that collected from 20 to 80 km zone (200,000, n = 27). The Kd-value was negative correlated with the concentration of stable ¹³³Cs and the electric conductivity in the dissolved fraction. This shows relatively higher mobility of radiocaesium in irrigation waters may occur when there are higher contents of cations present.

Source analysis of radiocesium in river waters using road dust tracers

Following the Fukushima Dai-ichi Nuclear Power Station accident, regional road dust, heavily contaminated with radiocesium, now represents a potential source of radiocesium pollution in river water. To promote effective countermeasures for reducing the risk from radiocesium pollution, it is important to understand its sources. This study evaluated the utility of metals, including Al, Fe, and Zn as road dust tracers, and applied them to analyze sources of ¹³⁷Cs in rivers around Fukushima during wet weather. Concentrations of Zn in road dust were higher than agricultural and forest soils, whereas concentrations of Fe and Al were the opposite. Concentrations of Zn were weakly but significantly correlated with benzothiazole, a molecular marker of tires, indicating Zn represents an effective tracer of road dust. Al, Fe, and Zn were frequently detected in suspended solids in river water during wet weather. Distribution coefficients of these metals and ¹³⁷Cs exceeded 10⁴, suggesting sorptive behavior in water. Although concentrations of Al, Fe, Zn, and ¹³⁷Cs were higher in fine fractions of road dust and soils than in coarse fractions, use of ratios of ¹³⁷Cs to Al, Fe, or Zn showed smaller differences among size fractions. The results demonstrate that combinations of these metals and ¹³⁷Cs are useful for analyzing sources of radiocesium in water. These ratios in river water during wet weather were found to be comparable with or lower than during dry weather and were closer to soils than road dust, suggesting a limited contribution from road dust to radiocesium pollution in river water.

Soil-soil solution distribution coefficient of soil organic matter is a key factor for that of radioiodide in surface and subsurface soils

We investigated the vertical distribution of the soil-soil-solution distribution coefficients (K_d) of ¹²⁵I, ¹³⁷Cs, and ⁸⁵Sr in organic-rich surface soil and organic-poor subsurface soil of a pasture and an urban forest near a spent-nuclear-fuel reprocessing plant in Rokkasho, Japan. K_d of ¹³⁷Cs was highly correlated with water-extractable K⁺. K_d of ⁸⁵Sr was highly correlated with water-extractable Ca²⁺ and SOC. K_d of ¹²⁵I^- was low in organic-rich surface soil, high slightly below the surface, and lowest in the deepest soil. This kinked distribution pattern differed from the gradual decrease of the other radionuclides. The thickness of the high-¹²⁵I^-K_d middle layer (i.e., with high radioiodide retention ability) differed between sites. K_d of ¹²⁵I^- was significantly correlated with K_d of soil organic carbon. Our results also showed that the layer thickness is controlled by the ratio of K_d-OC between surface and subsurface soils. This finding suggests that the addition of SOC might prevent further radioiodide migration down the soil profile. As far as we know, this is the first report to show a strong correlation of a soil characteristic with K_d of ¹²⁵I^-. Further study is needed to clarify how radioiodide is retained and migrates in soil.

Regression model analysis of the decreasing trend of cesium-137 concentration in the atmosphere since the Fukushima accident

The decreasing trend of the atmospheric ¹³⁷Cs concentration in two cities in Fukushima prefecture was analyzed by a regression model to clarify the relation between the parameter of the decrease in the model and the trend and to compare the trend with that after the Chernobyl accident. The ¹³⁷Cs particle concentration measurements were conducted in urban Fukushima and rural Date sites from September 2012 to June 2015. The ¹³⁷Cs particle concentrations were separated in two groups: particles of more than 1.1 μm aerodynamic diameters (coarse particles) and particles with aerodynamic diameter lower than 1.1 μm (fine particles). The averages of the measured concentrations were 0.1 mBq m^-3 in Fukushima and Date sites. The measured concentrations were applied in the regression model which decomposed them into two components: trend and seasonal variation. The trend concentration included the parameters for the constant and the exponential decrease. The parameter for the constant was slightly different between the Fukushima and Date sites. The parameter for the exponential decrease was similar for all the cases, and much higher than the value of the physical radioactive decay except for the concentration in the fine particles at the Date site. The annual decreasing rates of the ¹³⁷Cs concentration evaluated by the trend concentration ranged from 44 to 53% y^-1 with average and standard deviation of 49 ± 8% y^-1 for all the cases in 2013. In the other years, the decreasing rates also varied slightly for all cases. These indicated that the decreasing trend of the ¹³⁷Cs concentration was nearly unchanged for the location and ground contamination level in the three years after the accident. The ¹³⁷Cs activity per aerosol particle mass also decreased with the same trend as the ¹³⁷Cs concentration in the atmosphere. The results indicated that the decreasing trend of the atmospheric ¹³⁷Cs concentration was related with the reduction of the ¹³⁷Cs concentration in resuspended particles.

Concentration of radiocaesium in rice and irrigation water, and soil management practices in Oguni, Date, Fukushima

The concentration of radiocaesium ((134) Cs and (137) Cs) in brown rice collected from Oguni, Date, Fukushima in 2011 was over 500 Bq kg(-1) , which was the provisional regulation value in 2011, and rice cultivation was prohibited in 2012. Rice culture was resumed following the application of K fertilizer as a countermeasure in 2013. The concentration of (137) Cs in soils and irrigation water in 2013 was in the range of 1200 to 4000 Bq kg(-1) (n = 31) and 0.078 to 1.1 Bq L(-1) (n = 7), respectively. The concentration of (137) Cs in the dissolved fraction in irrigation water filtered with 0.45 µm pore-size membrane filter was a relatively constant at 0.019 to 0.038 Bq L(-1) (n = 7). The concentration of (137) Cs in brown rice cultivated in the paddy fields after implementing the countermeasure was 1.1 to 24 Bq kg(-1) dry weight (n = 29), which was lower than the Standard Limits (100 Bq kg(-1) ). However, the concentration of Cs in rice cultivated under a similar agricultural management as in 2011 and prior to the Tokyo Electric Power Company Holdings' (TEPCO) Fukushima accident was over the Standard Limits. Integr Environ Assess Manag 2016;12:659-661. © 2016 SETAC.

Addressing ecological effects of radiation on populations and ecosystems to improve protection of the environment against radiation: Agreed statements from a Consensus Symposium

This paper reports the output of a consensus symposium organized by the International Union of Radioecology in November 2015. The symposium gathered an academically diverse group of 30 scientists to consider the still debated ecological impact of radiation on populations and ecosystems. Stimulated by the Chernobyl and Fukushima disasters' accidental contamination of the environment, there is increasing interest in developing environmental radiation protection frameworks. Scientific research conducted in a variety of laboratory and field settings has improved our knowledge of the effects of ionizing radiation on the environment. However, the results from such studies sometimes appear contradictory and there is disagreement about the implications for risk assessment. The Symposium discussions therefore focused on issues that might lead to different interpretations of the results, such as laboratory versus field approaches, organism versus population and ecosystemic inference strategies, dose estimation approaches and their significance under chronic exposure conditions. The participating scientists, from across the spectrum of disciplines and research areas, extending also beyond the traditional radioecology community, successfully developed a constructive spirit directed at understanding discrepancies. From the discussions, the group has derived seven consensus statements related to environmental protection against radiation, which are supplemented with some recommendations. Each of these statements is contextualized and discussed in view of contributing to the orientation and integration of future research, the results of which should yield better consensus on the ecological impact of radiation and consolidate suitable approaches for efficient radiological protection of the environment.

Simultaneous determination of radiocesium ((135)Cs, (137)Cs) and plutonium ((239)Pu, (240)Pu) isotopes in river suspended particles by ICP-MS/MS and SF-ICP-MS

Due to radioisotope releases in the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, long-term monitoring of radiocesium ((135)Cs and (137)Cs) and Pu isotopes ((239)Pu and (240)Pu) in river suspended particles is necessary to study the transport and fate of these long-lived radioisotopes in the land-ocean system. However, it is expensive and technically difficult to collect samples of suspended particles from river and ocean. Thus, simultaneous determination of multi-radionuclides remains as a challenging topic. In this study, for the first time, we report an analytical method for simultaneous determination of radiocesium and Pu isotopes in suspended particles with small sample size (1-2g). Radiocesium and Pu were sequentially pre-concentrated using ammonium molybdophosphate and ferric hydroxide co-precipitation, respectively. After the two-stage ion-exchange chromatography separation from the matrix elements, radiocesium and Pu isotopes were finally determined by ICP-MS/MS and SF-ICP-MS, respectively. The interfering elements of U ((238)U(1)H(+) and (238)U(2)H(+) for (239)Pu and (240)Pu, respectively) and Ba ((135)Ba(+) and (137)Ba(+) for (135)Cs and (137)Cs, respectively) were sufficiently removed with the decontamination factors of 1-8×10(6) and 1×10(4), respectively, with the developed method. Soil reference materials were utilized for method validation, and the obtained (135)Cs/(137)Cs and (240)Pu/(239)Pu atom ratios, and (239+240)Pu activities showed a good agreement with the certified/information values. In addition, the developed method was applied to analyze radiocesium and Pu in the suspended particles of land water samples collected from Fukushima Prefecture after the FDNPP accident. The (135)Cs/(137)Cs atom ratios (0.329-0.391) and (137)Cs activities (23.4-152Bq/g) suggested radiocesium contamination of the suspended particles mainly originated from the accident-released radioactive contaminates, while similar Pu contamination of suspended particles caused by the accident could be neglected as the (240)Pu/(239)Pu atom ratios (0.182-0.208) were within the range of global fallout.

Changes in the chemical form of exogenous iodine in forest soils and their extracts

Information about the chemical form of exogenous iodine in soil is important for predicting the mobility and behaviour of radioiodine in the terrestrial environment. In this study, soil samples collected at various depths in a pine forest in Rokkasho, Japan, were spiked with stable iodine (as iodide or iodate); after incubation of the spiked soils for 1 or 14 d, the chemical forms of iodine were investigated in both the soils and their water extracts. In surface soil and its extracts, inorganic iodine was found to have been transformed to organically bound forms after incubation for 14 d, resulting in a decrease in the amount of water-extractable iodine in the soil. In contrast, in subsurface soil, which had low organic matter content, the predominant chemical form of iodine after incubation did not differ from that in the spiked soil, and the amount of water-extractable iodine did not decrease noticeably.

The role of tissue thromboplastin in the development of DIC accompanying neoplastic diseases

Procoagulant activity of gastric cancer tissues and leukocytes obtained from various types of leukemia have been studied with special reference to TTP. The following results were obtained. Homogenates of APL leukocytes and gastric cancer tissues contained strong procoagulant activities, most of which have been identified as TTP since the activities were neutralized by a specific antibody against purified human placenta TTP, inactivated by the removal of phospholipid with heptane-butanol mixture, and inactivated by the addition of phospholipase C. The delipidated homogenates regained procoagulant activities by relipidation procedures. These results also confirmed that TTP from APL leukocytes and gastric cancer tissues have the same lipoprotein properties as those of TTP in normal tissues. Though slight proteolytic activity and fibrinolytic activity were demonstrated in the homogenate of gastric cancer tissues, it was noted that the TTP activity was different from these two activities by partial purification of TTP from gastric cancer tissues. The TTP activity of 9 homogenates of gastric cancer tissues was 301 +/- 289 (mean +/- SD) units per mg protein, being higher in homogenates of mucinous adenocarcinoma and signet-ring cell carcinoma than in those of tubular and poorly differentiated adenocarcinoma. The mean TTP activity of leukocyte homogenates from 14 patients with APL and one out of 4 patients with CML in blastic crisis was 81 +/- 76 units/10(7) cells. The TTP activity of the homogenates of leukocytes from 7 out of 18 patients with AML and another patient with CML in blastic crisis ranged from one to six units/10(7) cells with a mean of 3.3 +/- 1.2. The TTP activity of leukocyte homogenates from the other 11 cases of AML, two cases of CML in blastic crisis, 6 cases of CML, and one case each of ALL and CLL were less than one unit/10(7) cells. In leukemic patients, all cases with a value of more than 202 for the product of units of TTP activity per 10(7) cells and differential count (%) of leukemic cells in the bone marrow smear (MU value) were accompanied by DIC. The MU value of leukemic patients correlated well to the plasma fibrinogen and serum FDP levels. All patients with a MU value of more than 277 died of DIC when a sufficient amount of heparin was not administered. On the other hand, no DIC developed in any of the patients with a MU value of less than 90.(ABSTRACT TRUNCATED AT 400 WORDS)

Relationship between the adsorption species of cesium and radiocesium interception potential in soils and minerals: an EXAFS study

This study examined the radiocesium (RCs) interception potential (RIP), cation exchange capacity (CEC), total organic carbon (TOC) content, and adsorption species in soils and minerals by using extended X-ray absorption fine structure (EXAFS) spectroscopy. The RIP related to Cs(+) adsorption by frayed-edge site (FES) has often been used to measure the mobility and bioavailability of RCs in the environment. This study found that the presence of organic matter (OM) can reduce RIP to a certain extent. The adsorption amount (=Q(T)) in soil was obviously correlated to RIP at a small [Cs(+)] region, whereas a linear relationship between Q(T) and CEC was observed at a large [Cs(+)] region. Both the inner-sphere (IS) and outer-sphere (OS) complexes of Cs(+) were observed through EXAFS at a molecular scale. The linear correlation between log (RIP/CEC) and the ratio of the coordination number (CN) of IS (=CNIS) and OS (=CNOS) complexes noted as CNIS/(CNIS + CNOS) suggested that the ratio of CN is very sensitive to Cs(+) adsorption species with variable RIP and CEC. The adsorption species of Cs(+) in soil was mainly dependent on the clay mineral content of soil. RIP was affected not only by FES but also by other strong adsorption sites, such as the interlayers and cavities identified as the IS complex in EXAFS analysis. Findings indicated that the EXAFS approach is a powerful and efficient tool to explore the behavior of Cs(+) in a given environment.

Relationship between the radiocesium interception potential and the transfer of radiocesium from soil to soybean cultivated in 2011 in Fukushima Prefecture, Japan

The concentration of radiocesium ((134)Cs and (137)Cs) in agricultural fields around Fukushima Dai-ichi Nuclear Power Plant (FDNPP) was elevated after the accident in March 2011. Evaluation of soil properties that influence phytoavailability of radiocesium is important for optimal soil management to minimize radiocesium transfer to crops. In this study, soybean grain and soil samples (0-15 cm) were collected from 46 locations in Fukushima Prefecture in 2011, and (137)Cs concentrations were measured. (137)Cs concentration ranges were 11-329 Bq kg(-1)-dry in soybean grain samples, and 0.29-2.49 kBq kg(-1)-dry in soil samples. The radiocesium interception potential (RIP) values in the soil samples ranged from 0.30 to 8.61 mol kg(-1). RIP negatively correlated with total carbon content and oxalate-extractable Si and Al + 1/2 Fe in the soils, suggesting that soils rich in organic matter and poorly crystalline clays tended to have lower RIP in this region. The soil-to-plant transfer factor for (137)Cs, analyzed in relation with various soil characteristics, varied by two orders of magnitude and was significantly negatively correlated with RIP and exchangeable K concentration in soil. The results show that RIP is useful for evaluating the efficiency of radiocesium transfer from soil to plants in this region.

Time-dependent changes of phytoavailability of Cs added to allophanic Andosols in laboratory cultivations and extraction tests

Although it is well known that phytoavailability of radiocaesium is gradually lost after its deposition on the ground by fixation to soil minerals, the decreasing rates during early period after the deposition is not yet quantitatively evaluated. In this study, stable Cs was added to 5 types of soil, including Andosols, a sand-dune regosol and a smectic lowland soil, in a laboratory soil incubation experiment to assess the aging effect of radiocaesium. Aliquots of a soil sample were put into pots and incubated in an artificial climate chamber. Orchardgrass or red clover was cultivated for 28 d in soil pots containing one of the allophanic Andosol samples seven times during about 1200 d using new pots for each cultivation. The soil-to-plant transfer factors of Cs declined exponentially until about 100 d and were almost constant thereafter. The extractabilities of Cs by water and 1 M NH4OAc solution from this allophanic Andosol soil sample also decreased with time and their decreasing patterns were similar to that of the transfer factor. The temporal changes of extractabilities of Cs in other soil samples were also examined 6 times during about 600 d. Rate of decline for the extracted yield of the added Cs by 1 M NH4OAc varied widely among all the soil types. Two allophanic Andosol samples showed relatively higher extractabilities in comparison with the other soils throughout the incubation experiment, which may be attributable to the lower contribution of Cs specific sorption sites to total cation exchange capacity of the allophonic Andosol soil samples.

Radiocesium and radioiodine in soil particles agitated by agricultural practices: field observation after the Fukushima nuclear accident

Three weeks after the accident at the Fukushima Daiichi Nuclear Power Plant, we determined the activity concentrations of (131)I, (134)Cs and (137)Cs in atmospheric dust fugitively resuspended from soil particles due to soil surface perturbation by agricultural practices. The atmospheric concentrations of (131)I, (134)Cs and (137)Cs increased because of the agitation of soil particles by a hammer-knife mower and a rotary tiller. Coarse soil particles were primarily agitated by the perturbation of the soil surface of Andosols. For dust particles smaller than 10 μm, the resuspension factors of radiocesium during the operation of agricultural equipment were 16-times higher than those under background condition. Before tillage, most of the radionuclides accumulated within a few cm of the soil surface. Tillage diluted their concentration in the uppermost soil layer.

The transfer of radiocesium from soil to plants: Mechanisms, data, and perspectives for potential countermeasures in Japan

The recent events at the Fukushima Daiichi nuclear power plant, Japan, have raised questions about radiocesium (137Cs) transfer from soil to agricultural plants. This transfer has been studied extensively in Europe following the Chernobyl accident, in Soviet Ukraine in 1986. This article briefly discusses whether that transfer may be different in Japan in the aftermath of the Fukushima accident.

Early recurrence after surgical resection in patients with pathological stage I non-small cell lung cancer

INTRODUCTION

Early recurrence is observed even in patients who undergo complete resection and had pathological (p-) stage I. Therefore, we focused on early recurrence, and attempted to elucidate the relationship between early recurrence and clinicopathological factors.

METHODS

Between May 1993 and December 2005, 1201 patients with non-small cell lung cancer (NSCLC) underwent surgical treatment at our institution. Of these, 402 patients who underwent complete resection and had p-stage I NSCLC were retrospectively analyzed for clinicopathological factors. Patients were divided into four groups according to the period between surgery and recurrence (R): no recurrence (NR, n = 331), late recurrence (LR, n = 28, R > 2 years), intermediate recurrence (IR, n = 22, 1 year < R < or = 2 years), and early recurrence (ER, n = 21, R < or = 1 year).

RESULTS

The overall 5-year survival rate for patients with p-stage I was 79.9 %. The overall 5-year survival rates were 91.0 %, 55.6 %, 17.1 %, and 7.5 % for the NR, LR, IR, and ER group, respectively. Preoperative high CEA level, lymphatic permeation, and pleural invasion were proven to be independent factors for overall recurrence. Moreover, multivariate analysis showed that preoperative CEA level, pathological T factor, lymphatic permeation, vascular invasion, and pleural invasion influenced early recurrence within one year.

CONCLUSIONS

The present study demonstrated that preoperative CEA level, pathological T-factor, lymphatic permeation, vascular invasion, and pleural invasion were independent prognostic factors for early recurrence within one year, even in patients with pathological stage I. In patients with these factors, adjuvant therapy may be indicated since this may improve their survival.

Effect of the counter anion of cesium on foliar uptake and translocation

Direct deposition of radioactive material onto crops is one important pathway for safety assessment of radionuclides released from nuclear facilities. Foliar uptake of Cs by radish (Raphanus sativus L. cv. Redchim) was studied by applying droplets of Cs solution (CsCl or CsNO3) on an upper leaf surface. The uptake of Cs was strongly affected by counter anions of Cs in the applied solution. Approximately 80% of Cs was absorbed for CsCl solution, while only 20% was absorbed for CsNO3. The partition of absorbed Cs between leaf and root tuber was quite similar for both Cs compounds, which indicated that behavior of the absorbed Cs in radish was the same for both.

Uptake and distribution of iodine in rice plants

Rice (Oryza sativa L.) plants were cultivated in an experimental field and separated at harvest into different components, including polished rice, rice bran, hull, straw, and root. The contents of iodine in these components and the soil were determined by inductively coupled plasma-mass spectrometry and radiochemical neutron activation analysis, respectively. Iodine content varied by more than three orders of magnitude among the plant components. Mean concentration of iodine in the entire plants was 20 mg kg(-1) dry weight, and the concentration of iodine in the surface soil (0-20 cm depth) was 48 mg kg(-1). The highest concentration of iodine (53 mg kg(-1) dry weight) was measured in root and the lowest concentration (0.034 mg kg(-1) dry weight) in polished rice. While the edible component (polished rice) accounted for 32% of the total dry weight, it contained only 0.055% of iodine found in the entire rice plants. Atmospheric gaseous iodine (5.9 ng m(-3)) was estimated to contribute <0.2% of the total iodine content in the biomass of rice plants; therefore nearly all of the iodine in the rice plants was a result of the uptake of iodine from the soil. The content of iodine in the aboveground part of rice plants was 16 mg kg(-1) dry weight and the percentage of iodine transferred per cropping from the soil into the aboveground biomass corresponded to 0.27% (20 mg m(-2)) of the upper soil layer content.

[Surgical outcome of tracheobronchial reconstruction for lung cancer]

We retrospectively evaluated the surgical outcome after sleeve lobectomy and pneumonectomy with tracheobronchial reconstruction for lung cancer. From 1993 to 2008, 46 patients with primary lung cancer underwent these surgical procedures. Seventeen patients (37%) received induction therapy, 15 received chemotherapy, while chemoradiotherapy or radiotherapy alone were received by one patient each. Sleeve lobectomy without carinal resection was performed in 41 patients. Carinal resection with 2 sleeve pneumonectomies was performed in 5 patients. There were no operative deaths. Bronchopleural fistula occurred in one patient, who required completion pneumonectomy. One patient presented local mucosal necrosis in the anastomotic site and was managed conservatively. Two patients had bronchial strictures as late complications and successfully dilated by a balloon using bronchoscopy. Overall 5-year and 10-year survival rates were 54% and 48%, respectively. No recurrence developed at any anastomotic site. The results showed that sleeve lobectomy and pneumonectomy with tracheobronchial reconstruction can be performed with low mortality and bronchial anastomotic complication rates. As well, local control of the tumor was satisfactory.