Estimation of rate constant for dissolution of radioactive fuel particles

Some theoretical of the experimental investigation of solubility of radioactive aerosols were examined. Filters, which were exposed during October-November 1987 in Pripyat town, were studied. Measurements on 22 November 1987 showed that an activity in the air was 12.1-20.8 mBq/m3 for 137Cs, 34.9-89.3 mBq/m-3 for 144Ce, 24.3-30.5 mBq/m-3 for 106Ru. Disperse structure of aerosol hot particles and the number of hot particles on each filter fragment was estimated by radiography. To determine a dissolution rate constant a static system with two 0.14 micron pore size membrane MFE filters (Dubna, Russia) enclosing fragments of Petryanov filters was selected. The composition was held in Gamble's solution lung fluid anf then in 0.1 mol/l HCl as dastic juice simulation. The activity of 90Sr, 238Pu, 239 + 240Pu, 241Am and 244Cm in aerosol filters and solutions was measured by radiochemical methods. It was shown that leaching of radionuclides from aerosol hot particles in lung fluid simulation decreases in line 137Cs > 90Sr > 239 + 240Pu > or = 241Am, depending om particle diameter and time. Dissolution constants were presented. Dissolution of aerosol particles in 0.1 mol/l HCl is also shown (dissolution time was 3 days). A radionuclide transition to HCl solution decreases in line 90Am 241Am > 137Cs > 239 + 240Pu. A transition degree reached 21% for 90Sr and extraction of 241Am was 3-17%.     

Plutonium,241Am,90sr,and137cs concentrations in some antarctic matrices

A radioecological survey in Antarctica shows that the^239+240Pu,²³⁸Pu,²⁴¹Am,⁹⁰Sr, and¹³⁷Cs activities were detectable in nearly all the samples. The activity level of^239+240Pu,²⁴¹Am, and¹³⁷Cs in antarctic sediments was about 5–20 times lower than in the northern Adriatic Sea sediments, but the²³⁸Pu activities were relatively high. It was interesting to note that the⁹⁰Sr concentrations in all the sediments tended to be low, which could be the result of the easier exchangeable behavior of⁹⁰Sr in water. High concentrations were detected in mosses and lichens and their activity levels were comparable to those in central Italy. The radionuclide ratio analyses show that the major part of^239+240Pu,²⁴¹Am,⁹⁰Sr, and¹³⁷Cs was a result of nuclear weapon tests. The higher²⁴¹Am/^239+240Pu ratio was observed and it could perhaps be the result of fallout of nuclear weapon tests prior to 1962. The²³⁸Pu/^239+240Pu ratio in the antarctic matrices was about seven times higher than in the Northern hemisphere and it could be inferred that the major part of²³⁸Pu was originating from the SNAP-9A satellite accident.     

Radioactive aerosols released from the Chernobyl Shelter into the immediate environment

The release of radioactive particles through large gaps in the containment of the destroyed Chernobyl reactor was assessed during two measurement periods. In 1996–1999, a total radionuclide flow rate of 274 Bq s⁻¹ or 8.64 × 10⁹ Bq year⁻¹ was determined. These releases were predominantly due to ¹³⁷Cs (78.5%), ⁹⁰Sr (21.1%), and ^239+240Pu (0.4%). The mean activity concentration in the aerosol measured directly at the gaps was about 240 mBq m⁻³ with an activity median aerodynamic diameter (AMAD) of 2.4 μm for ¹³⁷Cs, 120 mBq m⁻³ with an AMAD in the range 3.1–13 μm for ⁹⁰Sr, 1.8 mBq m⁻³ with an AMAD in the range 3.5–11 μm for ^239+240Pu, and 2.0 mBq m⁻³ with an AMAD of 1.5 μm for ²⁴¹Am. The resulting total inhalation dose rate calculated close to the gaps was about 100 nSv h⁻¹. In the near environment, the mean ¹³⁷Cs activity in the aerosol was 2.2 mBq m⁻³ with an AMAD of 2.2 μm, which gave rise to an inhalation dose rate of about two orders of magnitude lower than the corresponding dose rate at the gaps. Occasionally, however, dose levels were measured in the near environment that were similar to those at the gaps. In 2000–2003, lower activity concentrations were observed. The decrease was more pronounced at the gaps than in the near environment. The results indicate that effective dose due to inhalation must be considered for the dose assessment of construction workers who will be deployed at the Chernobyl site to reconstruct the old or to build the new Shelter, in the future.     

Influence of clay mineral type and organic matter content on the uptake of239Pu and241Am by plants

Summary The uptake of²³⁹Pu and²⁴¹Am from different clay mineral-organic matter-sand mixtures simulating contrasting soil types was examined in growth chamber experiments. The mixtures represented various combinations of organic matter (0, 5 and 10%), kaolinite (11 type) and montomorillonite (21 type) clay minerals, each at the levels of 5, 10 and 25%, and purified quartz sand (as filler).Results indicated a marked reduction in uptake of both²³⁹Pu and²⁴¹Am with increase in organic matter as well as clay content of the mixtures. The Pu Concentration Ratios (CRs) ranged from (2.5–7.0)×10^–3 in the case of kaolinite-organic matter mixtures, and from (0.9–5.5)×10^–3 in the case of montmorillonite-organic matter mixtures. The corresponding values of Am Concentration Ratios (CRs) obtained were (1.9–725.4)×10^–3 in the case of kaolinite-organic matter mixtures, and between (0.7–3.5)×10^–3 for the montmorillonite-organic matter mixtures.Reduction in the uptake of²⁴¹Am with increasing clay content was more pronounced in the montmorillonite clay-organic matter mixtures as compared to that in the case of kaolinite-organic matter mixtures. While similar qualitative reduction in²³⁹Pu CRs with increasing clay content was observed, the reduction was less marked than in the case of²⁴¹Am. The values for Am CRs were higher than the corresponding Pu CRs in kaolinite based mixtures whereas in the case of montmorillonite-organic matter mixtures Pu CRs exceeded the Am CRs.Increasing organic matter content and its interaction with both kaolinite and montmorillonite clay minerals were found to be equally effective in reducing the uptake of²³⁹Pu as well as²⁴¹Am by plants.     

Long-term development of the radionuclide exposure of murine rodent populations in Belarus after the Chernobyl accident

As a determinant of the associated health risks, the behavior of radionuclides in natural ecosystems needs to be better understood. Therefore, the activity concentration of various long-lived radionuclides released due to the Chernobyl accident, and the corresponding contributions to the whole-body dose rate, was studied as a function of time in mammalian indicator species inhabiting the natural forest ecosystems of Belarus, the bank vole (Clethrionomys glareolus) and the yellow-necked mouse (Apodemus flavicollus). The activity concentrations of ¹³⁷Cs, ¹³⁴Cs, ⁹⁰Sr, ²³⁸Pu, ^239,240Pu, ²⁴¹Pu and ²⁴¹Am in soil and in animals were measured at five monitoring sites with different ground deposition of radionuclides at different distances from the destroyed reactor. The observed temporal pattern of the radionuclide activity concentration in the studied animal populations reflects the changes in biological availability of these isotopes for biota, mostly due to fuel particle destruction and appearance of dissolved and exchangeable forms of radionuclides. The time course of ^134+137Cs activity concentrations in animal populations appeared as a sequence of increase, peak and decrease. Maximal levels of radiocesium occurred 1–2 years after deposition, followed by an exponential decrease. Concentrations of incorporated ⁹⁰Sr increased up to the tenth year after deposition. The activity concentrations of transuranic elements (²³⁸Pu, ^239,240Pu, ²⁴¹Pu and ²⁴¹Am) were much lower than those of the other radionuclides, in the studied animals. A considerable activity of ²⁴¹Am in animals from areas with high levels of contamination was firstly detected 5 years after deposition, it increased up to the tenth year and is expected to increase further in the future. Maximal values of the whole-body absorbed dose rates occurred during the year of deposition, followed by a decrease in the subsequent period. Generally, this decrease was monotonic, mainly determined by the decrease of the external γ-ray dose rate, but there were exceptions due to the delayed maximum of internal exposure. The inter-individual distributions of radionuclide concentrations and lifetime whole-body absorbed doses were asymmetric and close to log-normal, including concentrations and doses considerably higher than the population mean values.     

Organic forms of artificial radionuclide compounds in soil solutions from natural biogeocenosis

The date on the distribution of the main radiologicaly important polutants of biosphera (90Sr, 137Cs, 239 + 240Pu, 238Pu, 241Am) over the molecular mass fractions of organic matter in the soil solutions of natural environments are presented. Molecular mass constitution and radionuclide content in the fractions are dependent on radionuclide nature and type of soil and change along the soil profile. The major portion of 238Pu, 239 + 240Pu and 241Am (72-98%) was bound with organic matter in the soil solutions. In the case of organic horizons, these radionuclides were selectively connected with the fractions of high molecular masses (MMw > or = 2000). Radiostrontium is present principally in the fraction of inorganic compounds (19-100%) and in the low molecular mass fraction of organic matter (MMw = 350-500). A selective interaction of 137Cs with organic matter of definite molecular masses was not observed. The radionuclide was found in the "organic" fractions of a wide range of molecular masses (MMw from 350-500 to > or = 18,000) (34-97%) as well as in the fraction of inorganic compounds. The data obtained can provide the theoretical basis for explanation of higher mobility of 90Sr in soil profiles compared to other radionuclides.     

Bioavailability of 239+240Pu and 137Cs in aerosols and deposited dusts: a comparative study by fractional extraction

The bioavailability of ¹³⁷Cs and ^239+240Pu in soil, dust and aerosols has been determined by applying a fractional extraction procedure. In aerosols, 47–57% of ¹³⁷Cs was found to be easily exchangeable. This differs significantly from soil and deposited dust samples collected on a nearby street as well as on grassland where ¹³⁷Cs was quantitatively found in the acid-soluble fraction and the residue. A similar difference was observed for ^239+240Pu: 47% of ^239+240Pu in aerosols was associated with the organic fraction, while in soil and deposited dust from grassland 63–75% of ^239+240Pu was found in the acid-soluble fraction. In deposited street dust, 53% of ^239+240Pu was associated with the oxide fraction.     

Estimating Total Effective Dose Equivalents from Terrorist Use of Radiological Dispersion Devices

Radiological dispersion devices (RDDs), commonly called “dirty bombs,” utilize a conventional explosive to deliberately disperse non-fissile material as an aerosol. This analysis models total effective dose equivalent (Sv) at various locations down-wind from the detonation site subsequent to terrorists detonating a ²⁴¹Am, ¹³⁷Cs, ⁶⁰Co, ¹⁹²Ir, or⁹⁰Sr RDD. A source term for each isotope equaling 3.7 × 10¹³ Bq with an instantaneous release by either high explosives or low explosives at street level is assumed in order to evaluate total effective dose equivalent (TEDE) under various meteorological scenarios for intentional releases of non-fissile materials by terrorists. The inhalation pathway on average contributes most to TEDE. The inhalation pathway accounts for 96% (0.22 Sv) of the mean exposure estimate of 0.2321 Sv and occurs over an extremely short time frame (i.e., a few minutes). Ground shine, on average, contributes the second most to TEDE estimates accounting for approximately 4% (0.009 Sv) of the estimate. A cautionary note with regard to ground shine is warranted, however, because Hotspot estimates for this pathway are based on the assumption that a person is exposed for 4 days (96 hours). The TEDE for submersion (i.e., passing through the plume without inhaling particles) is negligible for the scenarios evaluated contributing less than 1% (5.2 × 10^?6 Sv) to the TEDE estimate averaged across all 140 model runs (5 nuclides × 2 rainfall scenarios × 2 explosive scenarios × 7 wind and atmospheric stability scenarios). The TEDE value for ²⁴¹Am from inhalation is much greater, on average, than the inhalation TEDE value for ⁶⁰Co, ¹³⁷Cs, ¹⁹²Ir, or ⁹⁰Sr. This underscores the potentially high risk to human health posed by exposure to ²⁴¹Am. Ground shine is the primary exposure pathway for ⁶⁰Co and ¹³⁷Cs due to the energetic and penetrating gamma rays those radionuclides emit. ¹⁹²Ir and ⁹⁰Sr have relatively low mean TEDE values for all of the pathways examined.     

Quantitative evaluation of 90Sr, 137Cs, 239Pu, 241Am transfer from polluted soil to gastric and intestine juice of cows

Quantitative parameters of 90Sr, 137Cs, 239Pu and 241Am transfer from solid phase of soil to gastric, intestine juice of cows as well as to imitating solutions have been estimated on the base of results of laboratory incubation experiments. A prevailing role of enzyme complex and microflora of gastrointestinal tract in radionuclides transfer from solid phase of soil to solution has been shown.     

90Sr, 137Cs, 238Pu, 239+240Pu,and 241Am radionuclides in macrophytes within the Krasnensky flood plain: species specificity of concentration and distribution in phytocenosis components

The analysis of the content of radionuclides 90Sr, 137Cs, 238Pu, 239 + 240Pu and 241Am in water vegetation of flood plain reservoirs has allowed studing features of radionuclide accumulation by various species of macrophytes and revealing bioindicators of radionuclide contamination. Thus species-specificity of radionuclide accumulation can essentially change the contribution of different species to a percentage ratio of the radionuclide content in phytomass of reservoirs in comparison with fund of higher aquatic plants.     

241Am dating of lake sediments

²⁴¹Am derived from decay of fallout ²⁴¹Pu is now frequently detected in analyses of lake sediments by low-background gamma assay, and offers an alternative to weapons test ¹³⁷Cs in dating recent sediments at those sites where the ¹³⁷Cs record has been degraded by post-depositional mobility or obliterated by Chernobyl fallout. Calculations of the in-growth of ²⁴¹Am from ²⁴¹Pu indicate a nominal distribution broadly similar to that of ¹³⁷Cs, with the maximum ²⁴¹Am activity occuring in fallout dating from 1963. Results from a number of sites suggest that ²⁴¹Am is significantly less mobile in lake sediments than ¹³⁷Cs, and that its distribution in cores reflects more closely the fallout record. Since further decay of existing weapons debris will increase ²⁴¹Am concentrations by about 24% over the next 40 years, ²⁴¹Am is likely to play an increasingly important role in assessing the validity of ²¹⁰Pb dates at sites with varying sediment accumulation rates.     

Association of Chernobyl-derived 239+240Pu, 241Am, 90Sr and 137Cs with different molecular size fractions of organic matter in the soil solution of two grassland soils

Radiocesium is normally bound only rather weakly and unspecifically by humic substances, in contrast to the actinides Pu and Am. Recently, however, it was observed that fallout ¹³⁷Cs in the soil solution from an Of-horizon of a podzol forest soil (slightly decomposed plant material) was associated essentially only with one single size fraction of the humic substances. In deeper soil layers with well humified material (AOh-horizon), radiocesium was associated with all size fractions of the dissolved organic matter (DOM). To examine whether this unexpected behaviour is also observable for DOM isolated from other soils, we determined the association of fallout ¹³⁷Cs,⁹⁰Sr,²³⁸Pu, ^239+240Pu and ²⁴¹Am with various size fractions of DOM from in situ soil solutions isolated from two layers (0–2 cm and 2–5 cm) of two grassland soils (a soddy podzolic soil and a peat soil) within the 10 km zone of the nuclear reactor at Chernobyl (Ukraine). The four size fractions of DOM as obtained by gel filtration of the soil solution were (mean nominal molecular weight in daltons): fraction I: ≥2000, fraction II: 1300; fraction III: 560, fraction IV: inorganic compounds. The results for the well humified DOM (humus accumulation horizon of podzol, deeper layer of peat soil) showed that Pu and Am are essentially associated with the high molecular weight fractions, while Sr is present only in the `inorganic' fraction. Radiocesium is found in all the size fractions separated. A quite similar pattern was also found for Pu, Am, and Sr in the soil solution from only slightly decomposed plant material (0–2 cm of peat soil), but not for radiocesium. This radionuclide was again essentially only observable in one single low molecular weight fraction of DOM. The above results thus support our recent observations in the different horizons of a forest podzol mentioned above, even though no reason for the different binding of radiocesium by well humified soil organic matter and by only slightly decomposed plant material can be given at present. The data demonstrate, however, that information on only the total amount of a radionuclide in the soil solution will not be sufficient to interpret or predict its fate adequately in the soil. Received: 13 February 1998 / Accepted in revised form: 14 July 1998     

The distribution of the radionuclides in the main components of lake ecosystems within the Chernobyl NPP exclusion zone

The results of the studies devoted to the distribution of radionuclides 90Sr, 137Cs, 238Pu, 239 + 240Pu and 241Am in 1998-2003 in main components of Glubokoe Lake and Dalekoe-1 Lake located within Krasnensky flood lands of the Pripyat River (inner exclusion zone of the Chernobyl NPP) were analysed. The data about the radionuclide content in bottom sediments, in water, in seston, in macrozoobenthos (including bivalvia molluscs), in gasteropods molluscs, in higher aquatic plants and in fish are presented.     

Radionuclide transfer to marine biota species: review of Russian language studies

An extensive programme of experiments on transfer of radionuclides to aquatic species was conducted in the former USSR starting from the early 1950s. Only a few of these studies were made available in the English language literature or taken into account in international reviews of radionuclide behaviour in marine ecosystems. Therefore, an overview of original information on radionuclide transfer to marine biota species available from Russian language literature sources is presented here. The concentration ratio (CR) values for many radionuclides and for marine species such as: ²³⁹Pu, ¹⁰⁶Ru and ⁹⁵Zr (crustacean), ⁵⁴Mn, ⁹⁰Sr, ⁹⁵Nb, ¹⁰⁶Ru, ¹³⁷Cs ²³⁹Pu, ²⁴¹Am and natural U (molluscs), and ⁵⁴Mn, ⁹⁰Sr, ¹³⁷Cs and ¹⁴⁴Ce (fish) are in good agreement with those previously published, whilst for some of them, in particular, for ³²P and ¹¹⁰Ag (crustaceans), ³⁵S (molluscs), ³²P, ³⁵S, ⁹⁵Nb, and ¹⁰⁶Ru (macroalgae) and ⁶⁰Co and ^239,240Pu (fish) the data presented here suggest that changes in the default CR reference values presented in recent marine reviews may be required. The data presented here are intended to supplement substantially the CR values being collated within the handbook on Wildlife Transfer Coefficients, coordinated under the IAEA EMRAS II programme.     

The use of fallout 137Cs and 239,240Pu for dating of lake sediments

The distribution of ¹³⁷Cs and ^239,240Pu in sediment core samples of the Finnish lakes Laukunlampi, Lovojärvi and Pääjärvi were determined. The sediment samples were collected using dry ice and liquid nitrogen freezing methods. The sediments of these lakes are annually laminated. A clear maximum concentration of ¹³⁷Cs and ^239,240Pu was found in sediment layers formed during 1962–1964, the years of maximum fallout, and the middle of the 1950's can be estimated from the ¹³⁷Cs and ^239,240Pu profiles. The highest concentrations, 11 500 and 820 pCi kg^–1 dry wt for ¹³⁷Cs and ^239,240Pu, respectively, were found in the sediment of Laukunlampi. The vertical distribution was similar for ¹³⁷Cs and ^239,240Pu in the lakes investigated. A slight migration of ^239,240Pu and ¹³⁷Cs was found and the migration of ¹³⁷Cs seems to be higher than that of ^239,240Pu. The advantages of ¹³⁷Cs dating method are rapidity and simplicity. ^239,240Pu is preferable when the sample size is small. The agreement found between ¹³⁷Cs and ^239,240Pu dates and the annual laminae show that these fallout radio isotopes can be used for dating sediments formed during the past 25 years.     

Concentration of Strontium-90 at Selected Hot Spots in Japan

This study is dedicated to the environmental monitoring of radionuclides released in the course of the Fukushima nuclear accident. The activity concentrations of β⁻ -emitting ⁹⁰Sr and β⁻/γ-emitting ¹³⁴Cs and ¹³⁷Cs from several hot spots in Japan were determined in soil and vegetation samples. The ⁹⁰Sr contamination levels of the samples were relatively low and did not exceed the Bq⋅g⁻¹ range. They were up four orders of magnitude lower than the respective ¹³⁷Cs levels. This study, therefore, experimentally confirms previous predictions indicating a low release of ⁹⁰Sr from the Fukushima reactors, due to its low volatility. The radiocesium contamination could be clearly attributed to the Fukushima nuclear accident via its activity ratio fingerprint (¹³⁴Cs/¹³⁷Cs). Although the correlation between ⁹⁰Sr and ¹³⁷Cs is relatively weak, the data set suggests an intrinsic coexistence of both radionuclides in the contaminations caused by the Fukushima nuclear accident. This observation is of great importance not only for remediation campaigns but also for the current food monitoring campaigns, which currently rely on the assumption that the activity concentrations of β⁻-emitting ⁹⁰Sr (which is relatively laborious to determine) is not higher than 10% of the level of γ-emitting ¹³⁷Cs (which can be measured quickly). This assumption could be confirmed for the samples investigated herein.     

Contrasting accumulation biokinetics and distribution of Am, Co, Cs, Mn and Zn during the whole development time of the eggs of the common cuttlefish, Sepia officinalis

Cuttlefish eggs were exposed to ²⁴¹Am, Co, Cs, Mn and Zn for different periods of time during the 50-d of the embryonic development at 17 °C. Exposures were carried out using background dissolved concentrations of the metals, using the corresponding γ-emitting radiotracers (²⁴¹Am, ⁵⁷Co, ¹³⁴Cs, ⁵⁴Mn and ⁶⁵Zn). Eggs were then placed in non-contaminating conditions. Experiments allowed assessing 1) the uptake and depuration kinetics of the selected elements and 2) their distribution among the different egg compartments (i.e. eggshell, vitellus, peri-vitelline fluid and embryo). ²⁴¹Am, Co and Zn were accumulated continuously by the eggs all along the development time, whereas Mn reached saturation after one month of exposure. Interestingly, the uptake kinetics of Cs tightly followed the weight variation of the eggs, mainly because of water influx/outflux. During the first month of the embryonic life, ²⁴¹Am, Co, Cs, Mn and Zn remained associated with the eggshell, indicating that the latter acted as an efficient shield against their penetration. Nevertheless, from this time onwards, Co, Cs, Mn and Zn accumulated more or less efficiently in the embryo according to the following order: Cs > Zn > Mn > Co. ²⁴¹Am was the only element tested that did not cross the eggshell all along the exposure time. The depuration kinetics revealed that the retention capacity of the eggs varied during the embryonic life. The contrasting accumulation biokinetics are discussed in terms of chemical and biological processes occurring during the cuttlefish egg development.     

Radiobiological effects on plants and animals within Semipalatinsk Test Site (Kazakhstan)

The Semipalatinsk Test Site (STS) was the main place of nuclear devices tests in the former Soviet Union. From 1949 to 1989 about 460 nuclear explosions have been carried out at STS. Radioactive contamination of STS territory has the extremely non-uniform character. The main dose-forming radionuclides are 137Cs, 90Sr, 152Eu, as well as 154Eu, 60CO, 239,240Pu and 241Am. The greatest specific activity of 137Cs and 239,240Pu in ground are n x 10(3) kBk/kg, 152Eu - 96 kBk/kg, 154Eu - 10.4 kBk/kg, 60Co - 20.5 kBk/kg, 241Am - 15 kBk/kg. However, up to now, within STS sites exists where gamma-dose rate comes to 60 microGy/h, that is enough for induction reliable biological effects in animals and plants. Inhabiting territory of STS plants and animals are characterized by increased level of mutagenesis, changes of morpho-anatomic indices and parameters of peripheral blood, by the increase of asymmetry bilateral indices, change of composition and structure of communities.     

Self-renewal capacity of murine hemopoietic stem cells under internal contamination with239Pu and241Am

Summary The self-renewal capacity of murine pluripotent hemopoietic stem cells (CFU-S) of vertebral bone marrow was studied under conditions of short-term and long-term internal contamination with²³⁹Pu or²⁴¹Am in female mice. Measurement of the CFU-S self-renewal capacity was carried out using double transplantation assay. To evaluate the production of differentiated progeny of stem cells average erythroblast numbers/visible spleen colony and⁵⁹Fe-uptake/colony were computed. The marrow cellularity/vertebra and the number of CFU-S/vertebra were decreased and affected more by²³⁹Pu than by²⁴¹Am. The production of erythroblasts per a single CFU-S and the⁵⁹Fe-uptake/colony were reduced, similarly the numbers of secondary spleen colonies and of secondary CFU-S in primary colonies. The above changes resulting from impaired functions of surviving CFU-S were more serious with²⁴¹Am than with²³⁹Pu. The biological effects of plutonium and americium appeared independent of the phase of contamination.     

Reconstruction and forecast of doses due to ingestion of <Superscript>137</Superscript>Cs and <Superscript>90</Superscript>Sr after the Chernobyl accident

The assessment doses due to ingestion of ¹³⁷Cs and ⁹⁰Sr for the population suffering from the Chernobyl accident was performed on the basis of the new mechanistic ecological model for assessment of radiological consequences of agricultural lands contamination (EMARC). The EMARC model allows estimation of internal doses based on ecological factors influencing the contamination of foodstuff, for the post-accidental years in the countries of the former Soviet Union. The EMARC model allows estimation of all quantities required in radiation hygiene practice. For example, the proposed analytical method may be used for both retrospective dose reconstruction and prospective estimates of annual dose and integrated “life-time” dose, for different age intervals. According to the EMARC model, estimated reference “life-time” doses for adults are between 7 and 269 μSv kBq⁻¹ m² for ¹³⁷Cs, and between 25 and 235 μSv kBq⁻¹ m² for ⁹⁰Sr. Maximal doses were estimated for persons who were 3, 9 and 11 years old, at the time of the accident and these doses exceed those for adults by a factors of 1, 5 for ⁹⁰Sr, and 1.4 for ¹³⁷Cs.