Measurement of individual external doses of Tokyo Electric Power Company Holdings employees working in Fukushima Prefecture and the relationship between individual external doses and air dose rates in areas including difficult-to-return zones.

Since the Fukushima Daiichi Nuclear Power Station accident, evacuation orders have been lifted except for the difficult-to-return zones (DRZs). Within the DRZs, there has been designated a special zone for reconstruction and revitalisation (SZRR). Decontamination of the SZRR has been promoted so that evacuation orders may be lifted. Previous studies measured individual external doses in the evacuation order-lifted zones (ELZs) and other living areas where the annual additional individual external dose was overall less than approximately 5 mSv y-1. However, there have been few reports about the measurement of individual external doses in a SZRR or outside of an SZRR (O-SZRR). In SZRRs and O-SZRRs, Tokyo Electric Power Company Holdings employees work mainly outdoors. Therefore, the employees' individual external doses and air dose rates were measured in these zones from March 2020 through January 2021. Our key results were:The median (minimum to maximum) individual external doses at outdoor locations were 0.16µSv h-1(0.05-0.63µSv h-1), 0.57µSv h-1(0.15-3.92µSv h-1), and 1.36µSv h-1(0.14-11.91µSv h-1) for the ELZ, SZRR, and O-SZRR, respectively.The conversion coefficients for the air dose rate measured by airborne monitoring to individual external dose were 0.23, 0.38, and 0.50 for the ELZ, SZRR, and O-SZRR, respectively. The conversion coefficients were below 0.6, which was used in the national government model for estimating external exposure dose from air dose rate. In addition, the conversion coefficients for the SZRR and O-SZRR in air dose rates of less than 1.5µSv h-1differed from those obtained for the entire measurement range of this study.The conversion coefficient from air dose rate at a height of 1 m above ground level to individual external dose was researched across a broader and higher range of air dose rates than in the previous study (0.24-20.89µSv h-1). The conversion coefficient is confirmed to be 0.7, similar to previous studies.

Evaluation of the effect of radioactivity to the environment in wooden houses within the evacuation area at Fukushima.

The accident at Fukushima Daiichi Nuclear Power Plant caused radioactive materials to spread outside the plant. To limit exposure in the area, air dose rates have been measured. When the dose rate exceeded the acceptable upper bound, the area was decontaminated by stripping the soil and washing roads. Immediately after the accident, it was not clear how much of an effect outdoor contamination had on dose rates inside houses. This paper discusses the effect of outdoor contamination on indoor air dose rates and factors influencing those dose rates based upon actual measurements taken of a wooden house standing on flat land in the area around the power plant. In addition, the effects of indoor horizontal distribution, height distribution, and decontamination are discussed using simple model simulations. As a result, the following was found, although within the range of air dose rates and location conditions measured in this study. Horizontal variation in indoor air dose rates decreases monotonically toward the centre of the house. Once decontamination has been performed, the overall dose rate decreases and variation becomes smaller. This trend is thought to be mainly due to expansion of a low-dose area. Vertical changes in indoor air dose rates are not straightforward. It is estimated that the dose rate decreases near the ground surface, then tends to increase going higher and finally decreases even higher up. This change in dose rates is thought to be due to the effect of radioactive materials permeating the soil. Recognition of the effects of these factors is important when estimating indoor air dose rates because indoor air dose rates are affected by the degree of decontamination, house size, and degree of penetration of radionuclides into the soil.

Fan-precooling effect on heat strain while wearing protective clothing.

This study compared heat strain during walking while wearing impermeable protective suits between fan-precooling and nonprecooling conditions. Six males engaged in 60 min of walking at a moderate speed (∼2.5 km/h) in a hot environment (37 °C, 40% relative humidity). Fanning using a fan (4.5 m/s) and spraying water over the body before wearing the suits produced significantly lower rectal temperature before the walking (37.3 ± 0.1 °C vs. 37.0 ± 0.1 °C, P < 0.05). In addition, whilst walking, rectal temperature was significantly lower in the precooling condition (maximum difference: 0.4 °C at 15 min of walking; 38.0 ± 0.1 °C vs. 37.8 ± 0.1 °C at the end of walking, P < 0.05). Although skin temperature decreased during fanning, no difference was observed during walking. Heart rate was lower in the precooling condition during the early stages of walking. Thermal and fatigue perceptions whilst walking did not differ between the conditions. Body weight loss was significantly lower in the precooling condition. These results may indicate that fan precooling attenuates exertional heat strain while wearing impermeable protective clothing. The fan-cooling method is practical, convenient, and yields lower heat strain during prolonged moderate exertion.

Correlação entre métodos de avaliação da qualidade da dose de diálise / Comparison between two methods for evaluation of the dialysis dose quality / La correlación entre los métodos de evaluación de la calidad de la dosis de diálisis

Objetivo: Verificar a correlação entre o Kt/V calculado e o Kt/V-OCM. Métodos: Estudo transversal, retrospectivo, com 14 pacientes submetidos a 106 hemodiálises com a máquina Fresenius 4008S, realizado numa Unidade de Terapia Intensiva para adultos, de um Hospital de Ensino do noroeste do Paraná, no período de novembro/2007 a abril/2008. Resultados: Através do teste de Shapiro-Wilk, (p>0,05), foi constatado que não houve distribuição normal entre o "Kt/V calculado" e o "Kt/V da máquina". Conclusão: Pelo teste de Wilcoxon concluiu-se que houve diferença significativa (p< 0,0001) entre as duas medições. Sugere-se a realização de novos estudos que levem em consideração todos os fatores envolvidos no cálculo on-line da depuração de uréia para que o Kt/V-OCM possa ser utilizado.

Purpose: To compare calculated Kt/V and Kt/V-OCM methods of dialysis dose. Methods: This was a cross-sectional retrospective study with 14 patients who underwent 106 hemodialysis using Fresenius 4008S dialysis machine in the critical care unit of the "Noroeste Parana Teaching Hospital" from November 2007 to April 2008. Results: Shapiro-Wilk test indicated that there was no normal distribution between the calculated Kt/V and the machine Kt/V (p>0.05). Wilcoxon test showed a statistically significant difference between the two measurements (p <.0001). Conclusion: There is a need for further studies that consider all factors involved with the online calculation of the urea depuration for the utilization of the Kt/V-OCM.

Objetivo: Verificar la correlación entre el Kt/V calculado y el Kt/V-OCM. Métodos: Estudio transversal, retrospectivo, con 14 pacientes sometidos a 106 hemodiálisis con la máquina Fresenius 4008S, realizado en una Unidad de Cuidados Intensivos para adultos, de un Hospital Docente del noroeste del Paraná, en el período de noviembre/2007 a abril/2008. Resultados: A través del test de Shapiro-Wilk, (p>0,05), se constató que no hubo distribución normal entre el "Kt/V calculado" y el "Kt/V de la máquina". Por el test de Wilcoxon hubo diferencia significativa (p< 0,0001) entre las dos mediciones. Conclusión: Se sugiere la realización de nuevos estudios que tengan en consideración todos los factores involucrados en el cálculo on-line de la depuración de urea para que el Kt/V-OCM pueda ser utilizado.

Bioelectronic sniffer for nicotine using enzyme inhibition.

A novel bioelectronic sniffer for nicotine in the gas phase was developed with enzyme inhibition principle to butyrylcholinesterase activity. The bioelectronic devices for nicotine in the gas and liquid phases were constructed using a Clark-type dissolved oxygen electrode and a membrane immobilized butyrylcholinesterase and choline oxidase. After the assessment of the sensor performances to choline and butyrylcholine as pre-examinations, the characteristics of the biosensor and bio-sniffer for nicotine were evaluated in the liquid and gas phases, respectively. The sensor signal of the bio-devices with 300 micromol l(-1) of butyrylcholine decreased quickly following application of nicotine and reached to the steady-state current, thus relating the concentration of nicotine in the liquid and gas phases. The biosensor was used to measure nicotine solution from 10 to 300 micromol l(-1). In the gas-phase experiment, the current signal of the bio-sniffer was also found to be linearly to the nicotine concentration over the range of 10.0-1000 ppb including 75.0 ppb as threshold limit value (TLV) by American Conference of Governmental Industrial Hygienists (ACGIH).

Correlation between the pituitary size and function in patients with asthenia.

To explore the relationship between pituitary morphology and function, we performed mid-sagittal MRI and endocrinological evaluation in 38 patients with asthenia. Six patients were diagnosed as having complete empty sella (ES) and 16 patients partial empty sella (PES). BMI, blood pressure, serum Na, ACTH, cortisol, TSH and T(4) were lower in ES group and PES group than in the group with normal pituitary size. Age in the patients with ES was oldest. Multiple regression analysis revealed that serum cortisol level was independently correlated with the size of the pituitary (beta = 0.586, p = 0.0069). Other variables, including age, BMI, blood pressure, serum Na, ACTH, TSH and T(4), were not correlated with the pituitary size when multivariate analysis was employed. In conclusion, there is a close relationship between the reduction of size of pituitary gland and the degree of adrenocortical dysfunction in asthenic patients. It is suggested that the pituitary-adrenal axis is especially vulnerable in empty sella syndrome, and therefore, meticulous evaluation of the hypophysial adrenal axis is recommended in subjects with reduced pituitary size even in elderly population.