Vertical Distribution and Estimated Doses from Artificial Radionuclides in Soil Samples around the Chernobyl Nuclear Power Plant and the Semipalatinsk Nuclear Testing Site

Abstract

For the current on-site evaluation of the environmental contamination and contributory external exposure after the accident at the Chernobyl Nuclear Power Plant (CNPP) and the nuclear tests at the Semipalatinsk Nuclear Testing Site (SNTS), the concentrations of artificial radionuclides in soil samples from each area were analyzed by gamma spectrometry. Four artificial radionuclides (241Am, 134Cs, 137Cs, and 60Co) were detected in surface soil around CNPP, whereas seven artificial radionuclides (241Am, 57Co, 137Cs, 95Zr, 95Nb, 58Co, and 60Co) were detected in surface soil around SNTS. Effective doses around CNPP were over the public dose limit of 1 mSv/y (International Commission on Radiological Protection, 1991). These levels in a contaminated area 12 km from Unit 4 were high, whereas levels in a decontaminated area 12 km from Unit 4 and another contaminated area 15 km from Unit 4 were comparatively low. On the other hand, the effective doses around SNTS were below the public dose limit. These findings suggest that the environmental contamination and effective doses on the ground definitely decrease with decontamination such as removing surface soil, although the effective doses of the sampling points around CNPP in the present study were all over the public dose limit. Thus, the remediation of soil as a countermeasure could be an extremely effective method not only for areas around CNPP and SNTS but also for areas around the Fukushima Dai-ichi Nuclear Power Plant (FNPP), and external exposure levels will be certainly reduced. Long-term follow-up of environmental monitoring around CNPP, SNTS, and FNPP, as well as evaluation of the health effects in the population residing around these areas, could contribute to radiation safety and reduce unnecessary exposure to the public.

Evaluation of the Relationship between Current Internal 137Cs Exposure in Residents and Soil Contamination West of Chernobyl in Northern Ukraine

“…We evaluated soil contamination only from 0–5 cm in depth. A recent analysis of soil contamination in Masany, Belarus (which is 8km from the Chernobyl Nuclear Power Plant) reported that the concentration of detected 137 Cs was higher in surface soil (0–5cm) samples than in lower layers (5–10cm), and that prevalent radionuclides had accumulated mainly in the surface layer [ 19 ]. With regard to samples from the family farm, the residents have been cultivating their farm for many years to a depth of more than 20 cm with a hoe and farm tractor, and so the contamination level of soil should be the same as the depth at which crops can take root and grow.…”

Allogeneic Neural Stem/Progenitor Cells Derived From Embryonic Stem Cells Promote Functional Recovery After Transplantation Into Injured Spinal Cord of Nonhuman Primates

“…The OCT compound-embedded frozen blocks were sectioned at a thickness of 16 mm and incubated with 5% BLOCK ACE (AbD Serotac) with 0.1% saponin in 0.1 M phosphate buffer [31] for 1 hour. The sections were stained with primary anti-GFP antibody (rabbit IgG, 1:100; Medical and Biological Laboratories Co., Ltd., Nagoya, Japan, http://www.mbl.co.jp) for 72 hours and Alexa Fluor 488 and nanogold conjugated anti-rabbit secondary antibody (1:100, Invitrogen) for 24 hours at 4°C.…”

Determination of the activity concentration levels of the artificial radionuclide137Cs in soil samples collected from Qatar using high-resolution gamma-ray spectrometry

“…He and H. Kato [2][3] that the relaxation mass depth increases as the content of clay in the soil increases, 4 which is due to their high composition of aluminum silicates (anion) that easily adsorb radionuclide cations on their surface. Hence, since clay particles are characterized as fine sized grains, their surface will have also greater specific areas and accordingly will adsorb more.…”

“…Hence, since clay particles are characterized as fine sized grains, their surface will have also greater specific areas and accordingly will adsorb more. 4 Although migration of 137 Cs is relatively low in soil, 1 it has a relatively long half-life that makes long-term monitoring of the activity concentration in river water, ground water and vegetation essential, especially in an area known for its elevated levels of Cs. 1 The investigated samples in this study were collected before the 2011 Fukushima Daiichi nuclear power plant accident as a part of a comprehensive study aimed at establishing a baseline map for the natural and artificial radionuclides across the landscape of the State of Qatar.…”