March 2016

What have we learned from the ecological studies carried out overthe long term on the fauna and flora of the territories contaminatedby the Chernobyl and Fukushima accidents?
Thirty and five years respectively after the two major nuclear accidents that
occurred at the Chernobyl and Fukushima power plants, the ecological studies
carried out on the fauna and flora exposed to chronic ionising radiation deliverconclusions that are often contradictory, notably due to the complexity of themultidisciplinary approaches that need to be deployed for an unbiased
interpretation of the effects observed.
A very wide variety of biological effects have been reported in literature following observations ofplant and animal species living in contaminated territories in the Chernobyl exclusion zone (and on
a broader level, in the contaminated territories of Belarus) as well as in the evacuated areas of
Fukushima. Publications concerning invertebrate, vertebrate and plant species report either theabsence of effects or effects of varying intensity e.g. on development, growth, behaviour andreproduction. One of the finalised objectives of these studies carried out in situ mainly from the
2000s onwards for the Chernobyl exclusion zone and only a few months after the Fukushima
accident was - and remains - to produce a diagnosis and a forecast of the consequences of theseeffects on the demographics of the populations of native species exposed to chronic ionisingradiation and in fine of the existence of damage to the structure and functioning of the ecosystems.
In order to establish a definite link between exposure to ionising radiation and the effects observed,
these studies must clearly be multidisciplinary in order to prevent multiple interpretation biases(Figure 1).
State of the art in non-human species radiobiology
Logistic model

10% effect on
response compared
to control(Dose rate = 0)Abundance

Dose rate

Ecological datasets describing abundance anddiversity of species in situ

10% effect on responsecompared to control(Dose rate = 0)
EDR10

EDR10

Location and date of observation
Observed effecte.g., number of individuals, biometry, reproductive capacity
Descriptive environmental variables
e.g., temperature, time of observation, cloud cover, type of land coverCharacteristics of radioactive contamination for habitats and living organismes

Hormetic model

Response

Response

Field observations respecting
ecological standards

Dose rate

Interpretation of the relationshipbetween chronic exposure toionising radiation and ecologicaleffects observed in contaminatedterritories

Absorbed dose

Absorbed dose reconstruction forobserved individuals on the basis ofradionuclide measurements inmedia/organisms

Statitical models
To represent at best the full datasets,taking into account environmental
variables (e.g. temperature, time ofobservation, cloud cover, type of land
cover ), for the study area and thecensus period

Figure 1 - Integrated multidisciplinary approach requested for the correct interpretation of ecological observations(e.g. abundance and diversity of the species present) conducted on radio-contaminated territories.

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Morphological anomalies in pine trees are observed at Chernobyl as well as
Fukushima. The frequency of occurrence of these anomalies would appear to
be correlated with the dose absorbed by the trees, but the dosimetricestimations proposed by the authors are incomplete and do not enable solid
dose-effects relations to be established.
In the Chernobyl exclusion zone, modifications to plant communities are undeniable with, in theacute phase of the accident, the death of pines1 around the damaged reactor, followed by the
progressive establishment of new herbaceous species and deciduous trees. In the highlycontaminated areas where conifers have been able to persist, since 1993, 50-60% of young trees
aged between two and nine years present abnormal morphogenesis (Zelena et al., 2005), in
particular a loss of apical dominance (i.e. loss of the apical bud) in conjunction with the death of
the buds' meristems (tissue responsible for growth). On the other hand, anomalies concerning
reproductive capacities have not been significant since 1995. The most recent analyses conductedon pines planted in the exclusion zone after the accident and subject to chronic exposure haveshown that 10% and 50% of the trees exposed to a total dose rate (external and internal irradiation)of 1 and 40 µGy/h respectively, present morphological anomalies (Yoschenko et al., 2011).
Mousseau et al. (2013) reported an effect on the growth of pines at Chernobyl depending on theabsorbed dose; however their study shows limitations with regard to the estimation of the level of
exposure that was only evaluated through the ambient dose rate, ignoring the contribution of theinternal contamination of the trees at the absorbed dose. To date, only one study addressing theconsequences to trees of fallout from the Fukushima accident has been published (Watanabe et al.,2015)2. For sites in the contaminated territories where the 2015 ambient dose rate lies between 5
and 40 µGy/h, a significant frequency of increased loss in the apical dominance of the Japanese fir(Abies firma) is highlighted (Figure 2). Although this study contains weaknesses in its statisticalanalysis and does not present an estimation of the cumulative dose by the trees, the frequencies ofoccurrence of the damage are consistent with the observations highlighted in the Chernobyl pines.
Moreover in these studies, where the dose absorbed by trees is somewhat underestimated inrelation to the real dose - due to the contribution of internal contamination not being taken into
account - dose rates are generally of the same order of magnitude than the variation range of dose
rates corresponding to a very low probability of the occurrence of deleterious effects on individuals
published by CIPR 108 (CIPR, 2008), i.e. 4 to 40 μGy/h, and consistent with those implying
morphological damage (from 40 to 400 µGy/h).

1During the first weeks following the accident, 90% of pines (Pinus sylvestris L.) died in a 6 km2 zone around the power plant
due to the lethal dose absorbed of 60-100 Gy (Geras’kin et al., 2008).
2
This study was the subject of an IRSN information note published on the institute's website in 2015 (in French :http://www.irsn.fr/FR/Actualites_presse/Actualites/Documents/IRSN-Note-Lecture-Fukushima-PinContamination_20151110.pdf)

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Ambient dose rate

Représentation schématique de la croissance des pins japonais

Axe principal

Pousse terminale

Non-contaminatedsites

sur le site témoin

0.1 µGy/hBourgeon sommital Bourgeons de 2015
Bourgeons latéraux
Verticille de 2014
Verticille de 2013
Verticille de 2012
Verticille de 2011
Verticille de 2010
Brancheslatérales

2011

2012

2013

2014

2015

Contaminated
sur les sites contaminés sites 5 to 40 µGy/h

Loss ofapicalPertedubudbourgeon sommital

Loss of main axis

Perte de l’axe principal

AbnormalgrowthCroissance« buissonnante»Absorbed dose rates
42

No effect: 4 to 40 µGy/hMorphological deffects : 40 to 400 µGy/h

Figure 2 - Schema summarising the study of Japanese pines revealing a significant increase in morphologicalanomalies in pines depending on the ambient dose rate at the observation site. Comparison with knowledge about the effectsof ionising radiation in pines published by the CIPR (2008).

The effects observed on the abundance of terrestrial invertebrates depend on
the groups of species studied. For some of these groups only, the evolution ofabundance with the ambient level of exposure is different at the Chernobyl and
Fukushima sites. According to the authors, the differences in radiosensitivity
between species and the effects linked to chronic exposure over several
generations are the main explanations behind these differences.
In invertebrates, Jackson et al. (2005) observed a decrease in the diversity (but not abundance) of
soil invertebrates in the Chernobyl exclusion zone for external dose rates ranging between 0.1 and140 µGy/h. Møller et Mousseau (2009), for their part, showed a reduction in the abundance ofinsects (bees, grasshoppers, butterflies, dragonflies) and spiders for external doses of an order ofmagnitude below those published by Jackson et al. (2005). The decline in the abundance ofpollinators in the contaminated zones seems to be accompanied by a decrease in fruit production inthese same areas (Møller et al., 2012a). Lecomte-Pradines et al. (2014) demonstrated a moderate
effect of exposure to ionising radiation on the assembly of nematodes3 collected from forest sites 25
years after the accident, putting forward the hypothesis of the rapid disappearance of the mostsensitive species following the accident due to a much higher level of exposure. More recently, a
study conducted on invertebrates collected from contaminated sites in the exclusion zone shows apositive correlation between the abundance of certain taxons and the ambient dose rate, whilst
other taxons show a negative correlation (Bezrukov et al., 2015). The authors attribute thisheterogeneity to a difference in sensitivity regarding exposure to ionising radiation. Finally, a study
shows that the descendants of grasshoppers from contaminated sites in the exclusion zone present
anomalies with regard to development, survival and reproductive success (Beasley et al., 2012). To

3

Nematodes are small millimetric worms, found in very diverse environments (fresh/brackish water, soils).

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date, only very few studies address the consequences of the Fukushima accident on invertebrate
populations. A study carried out on different taxons suggests that the abundance of butterflies andcicada is negatively impacted by exposure to radioactive contamination. However, unlike
Chernobyl, no association between the absorbed dose and the abundance of dragonflies,
grasshoppers and bees was observed after the first summer following the disaster. An increase in
the number of spiders was even observed at the most contaminated sites (Møller et al., 2013). The
butterfly Zizeeria maha has been used in order to monitor and understand the impact of thecontamination from the Fukushima accident4. Adults sampled from the contaminated sites in 2011
show morphological anomalies that are not observed at control sites, nor impacted by radioactive
fallout. These morphological anomalies are even more acute in the next two generations obtained
under control conditions (Hiyama et al., 2012). The monitoring of the populations of this butterfly
in contaminated zones between 2011 and 2013 shows a progressive return to normal after two years(Hiyama et al., 2015). Nohara et al. (2014) reproduced, in the laboratory, the increase in themortality and morphological anomaly rates by feeding larvae of butterflies from a control zone withleaves collected in a contaminated area. This result underlines the importance of taking theinternal dose into account when evaluating effects (Nohara et al., 2014) but does not inform about
the absorbed doses having led to the occurrence of the effects or the molecular mechanisms at theorigin of these phenomena. Similarly, acute morphological anomalies as well as increased mortality
have been observed in aphid samples taken in spring 2012 from the contaminated zone close to the
Fukushima Dai-ichi power plant. Nevertheless, these malformations have not been transmitted to
the next generation and, in 2013, the authors observed an improvement compared to 2012
(Akimoto, 2014).

Bird communities have been the subject of long-term observations in the
Chernobyl exclusion zone and in the contaminated territories of Fukushima.
According to the authors of the publications, the decline in abundance observedin both cases has been correlated with the increase in the ambient dose rate. A
recent IRSN study based on a dosimetric reconstruction in Fukushima
birds,showed that the effects observed were consistent with knowledge about
the reduction in reproductive capacity linked to the increase in absorbed doses.
Various publications by Møller et Mousseau (Møller et al., 2006; Møller et Mousseau, 2009) address,
through eco-epidemiological style approaches, the consequences of chronic exposure to ionisingradiation in bird populations in the Chernobyl exclusion zone. These studies demonstrate that, morethan 30 years after the accident, the specific richness, abundance and density of bird populations in
the forest environment decrease with the increase in the level of exposure to ionising radiation. The
authors conclude as to the cause of this drastic decrease via a statistical relationship between
estimated exposure levels and the intensity of the effects observed at said levels of exposure: theabundance of birds would appear to fall by 60% between "high-level irradiation" sites with 0.1 to 1
mGy/h in external irradiation (without however providing information on the level of internal
contamination) and the so-called "control" sites, with around 0.1 µGy/h in external irradiation. The
authors put forward the hypothesis of a direct effect of exposure levels to ionising radiation on
survival and fertility rates (25% in contaminated zones), reducing population size (Møller et al.,2005) and/or associated indirect effects to avoidance behaviour regarding contaminated habitats(Møller et Mousseau, 2007a) or to a reduction in the abundance of food, essentially comprising soil
invertebrates (Møller et Mousseau, 2007b; 2009). The susceptibility of birds differs depending on
gender and life stage. Thus, age ratios observed in bird populations in the exclusion zone favour
younger life stages, indicating significant mortality in adults. Also, the gender ratio strongly favours
males in the most contaminated zones (Møller et al., 2012b).
4

This study was the subject of an IRSN information note published on the institute's website in 2012 (In French:
http://www.irsn.fr/FR/Actualites_presse/Actualites/Documents/IRSN_NI_Effet-biologique-Fukushimapapillon_08102012.pdf).

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These effects on life history traits are accompanied by physiological or morphological changes. A
high rate of morphological anomalies (e.g. partial albinism, beak malformations, tumours) is also
observed in swallows in the exclusion zone, associated with a lower survival rate (Møller et al.,2007). In addition, bird populations from the exclusion zone, all species combined (546 individuals
from 48 sampled species), present significantly smaller brains than in the control zones. The authors
quantify a reduction of 5% in brain volume when the dose rate varies between 0.02 µGy/h and 100µGy/h (Møller et al., 2011). In another study carried out by this team, the incidence of cataracts
increases with the level of ambient radiation (57 species sampled) (Mousseau et Møller, 2013).
In Fukushima also, a fall in the abundance of birds was observed (45 species) with increasing
ambient dose rate levels between March and July 2011 (Møller et al., 2012b). This decline isaccentuated over time (from 2011 to 2014, 57 species) (Møller et al., 2015). Based on this dataset
describing the Fukushima bird community, Garnier-Laplace et al. (2015) carried out dosimetricreconstruction research making it possible to take into account external and internal irradiation
channels in order to estimate the absorbed dose, as well as specificities regarding the exposure ofbirds based on their lifestyle. As a result, reconstructed dose rates can be higher, up to factor 20,
compared to the ambient dose rates measured in situ by portable survey meters. This new analysis
has provided a framework to quantify that 90% of species are chronically exposed to dose rates
liable to affect their reproduction, confirming the conclusions of Møller et al. (2015) with regard to
the link between exposure levels and deleterious effects on bird abundance. The statistical analysis
based on the reconstructed dose reveals a significant negative effect from the total absorbed doseon the total number of birds within the community observed in a 50 km radius of the damaged
Fukushima power plant over the period 2011-2014 (Garnier-Laplace et al., 2015)5.

The evacuation of human populations is considered to be a deciding factor
concerning the return of animals to the contaminated territories by certain
authors having published works on the large mammals of the Belarusian
reserves. In a study that has just been submitted to Biology letters, IRSN
demonstrates, with regard to Fukushima bird communities, that the evacuation
status of the zones where observations are carried out does not modify the fallin abundance due to the increase in absorbed dose, but that the abundance ishigher in these zones compared to non-evacuated areas. 6
At the present time, the question relating to the influence of the evacuation of human populations
from contaminated territories on the diversity and abundance of animal species is subject todebate. Two recent studies conducted on mammals in the Chernobyl exclusion zone arecontradictory. Their abundance has been studied via the counting of tracks in the snow (Møller andMousseau, 2013). Of the 12 species identified, abundance was correlated negatively with theambient dose rate, with very marked effects for certain species such as foxes, and much lower forother species such as wolves. The second study paired up multi-annual campaigns to count tracks inthe snow as well as counts via aerial surveillance, providing indications as to the dynamics of the
mammal populations (Deryabina et al., 2015). The authors conclude that the density of the
mammals is not correlated with radioactive contamination. Furthermore, densities of large
ungulates, such as elk, roe deer or wild boar, are comparable to those observed in uncontaminatednature reserves, with the wolf density in the exclusion zone even being seven times higher than thatobserved in said reserves. Finally, 10 years of aerial surveillance data between 1987 and 1996 show
an increase in the densities of elk, roe deer and wild boar. Nevertheless, this data does not enable a
comparison between the temporal evolution studied in Belarus and that observed in identical
5This publication was the subject of an IRSN information document at the time of its publication in November 2015(http://www.irsn.fr/EN/newsroom/News/Documents/IRSN_Information-Note_Fukushima-Impact-Birds_20151124.pdf)
6
One of these reserves (Polessye State Radioecological Reserve), corresponds to the Belarus sector of the Chernobyl
exclusion zone;

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climate zones in Europe, nor does it allow for a separation between the positive effect due to theabandonment of the exclusion zone by human populations (leading to a halt in hunting, farming andlogging) and from a potential negative effect of ionising radiation. To date, only one recent IRSN
study answers this last question in a thorough manner, based on the statistical analysis of ecological
data describing the bird community observed within a 50 km radius of the damaged Fukushima
power plant over the period 2011-2014 (Garnier-Laplace et al., submitted). On the basis of thestatistical model best representing the entire dataset including the total reconstructed absorbed
dose for birds, and taking into account confusing descriptive variables of environmental conditions(e.g., temperature, time of observation, snow cover, type of landscape), for the zone and study
period, IRSN has estimated that the absorbed dose has more weight in the reduction in the total
number of birds than the evacuation of human populations (Figure 3).

The influence of exposure to ionising radiation (absorbed dose) issimilar whatever the evcuation status of the zone (same slope for the
relationship between dose and abundance).
The total number of birds is intrisically higher in evacuated zone.

Bird absorbed doses expressed in Gy (Log10)
Figure 3 - Relationship between the dose absorbed by birds and the abundance of individuals by observation siteaccording to the evacuation status of the zone where the site is located (adapted from Garnier-Laplace et al.,submitted).

In conclusion
There exist numerous ecological studies conducted in the contaminated territories following thetwo major nuclear accidents at Chernobyl and Fukushima that demonstrate the existence of effects
on animal and plant species in relation to the radioactive contamination of the territories.
Nonetheless, the review of publications in this field does however reveal shortcomings incooperation between the basic scientific disciplines; a situation that can lead to biased conclusions.
IRSN's latest work, bringing its expertise in dosimetry and radiobiology to the analysis of ecological
data from the observation of the Fukushima bird community, illustrates the benefits brought bycooperation between these disciplines in order to draw solid conclusions about the ecologicalconsequences of a nuclear accident. By multiplying this type of integrated analysis, answers will befound to important questions that are still pending, such as transgenerational effects, theadaptation of organisms to stress, the mechanisms governing the difference in radiosensitivity
between species, etc…
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To find out more - A longer version of this summary is available in the form of an IRSN report(C. Adam-Guillermin, O. Armant, J-M Bonzom, P. Henner, C. Lecomte. "Ecological consequences of
the Chernobyl nuclear accident". IRSN report N°PRP-ENV/SERIS/2016-06).

References
Akimoto S.I. (2014). Morphological abnormalities in gall-forming aphids in a radiation-contaminated area near
Fukushima Daiichi: selective impact of fallout? Ecology and Evolution 2014; 4(4):355–369
Beasley D.E., Bonisoli-Alquati A., Welch S.M., Møller A.P., Mousseau T.A. (2012). Effects of parental radiation
exposure on developmental instability in grasshoppers. J. Evol. Biol. 25: 8-9:
Bezrukov V., Møller A.P., Milinevsky G., Rushkovsky S., Sobol M., Mousseau T.A. (2015). Heterogeneous
relationships between abundance of soil surface invertabrates and radiation from Chernobyl. Ecological
Indicators 52: 8-9:
CIPR, Commission Internationale pour la Protection radiologique (2008). Environmental protection: the concept
and use of reference animals and plants. Annals of the ICRP 30: n°4-6.
Deryabina T.G., Kuchmel S.V., Nagorskaya L.L., Hinton T.G., Beasley J.C., Lerebours A., Smith J.T. (2015).
Long-term census data reveal abundant wildlife populations at Chernobyl. Current Biology 25, Issue 19,
pR824–R826.
Garnier-Laplace J., Beaugelin-Seiller K., Della-Vedova C., Métivier J.M., Ritz C., Mousseau T.A., Møller A.P.
(2015). Radiological dose reconstruction for birds reconciles outcomes of Fukushima with knowledge of
dose-effect relationships. INCLUDING 2,800 SCIENTISTS
Garnier-Laplace J., Beaugelin-Seiller K., Della-Vedova C., Mousseau T.A. & Møller A.P. (soumis). Bird
communities near Fukushima are more impacted by radiation dose than by evacuation of humans.
Biology Letters, soumis en Février 2016.
Geras’kin S.A., Fesenko S.V., Alexakhin R.M. (2008) Effects of non-human species irradiation after the
Chernobyl NPP accident. An international environment 8-9:
Hiyama A., Nohara C., Kinjo S., Taira W., Gima S., Tanahara A., Otaki J.M. (2012). The biological impacts of
the Fukushima nuclear accident on the pale grass blue butterfly. Scientific Reports, 2, 570.
http://doi.org/10.1038/srep00570
Hiyama A., Taira W., Nohara C., Iwasaki M., Kinjo S., Iwata M., Otaki J.M. (2015). Spatiotemporal abnormality
dynamics of the pale grass blue butterfly: three years of monitoring (2011–2013) after the Fukushima
nuclear accident. BMC Evolutionary Biology 15:15.
Jackson D., Copplestone D., Stone D.M., Smith G.M. (2005). Terrestrial invertebrate population studies in the
Chernobyl exclusion zone, Ukraine. Radiation protection. 1. 40, S857-S863.
Lecomte-Pradines C., Bonzom J.-M., Della-Vedova C., Beaugelin-Seiller K., Villenave C., Gaschak S., Coppin F.,
Dubourg N., Maksimenko A., Adam-Guillermin C., Garnier-Laplace J. (2014). Soil nematode assemblages
as bioindicators of radiation impact in the Chernobyl Exclusion Zone. Science of the Total Environment,
490, pp. 161-170.
Møller , A.P., Nishiumi I., Suzuki H., Ueda K., Mousseau T.A. (2013). Differences in effects of radiation onabundance of animals in Fukushima and Chernobyl. Ecological Indicators, 24:75-81.
Møller A. P., Nishiumi I., Mousseau, T. A. (2015). Cumulative effects on interspecific differences in response ofbirds to radioactivity from Fukushima. J. Ornithol. in press
Møller A.P. , Mousseau T.A. (2006). Biological consequences of Chernobyl: 20 years on. Trends Ecol Evol, 2006.
09/12/14 8-9:
Møller A.P., Mousseau T.A., de Lope F., Saino N. (2007). Elevated frequency of abnormalities in barn swallows
from Chernobyl. Biology Letters of the Royal Society, 3: 8-9:
Møller A.P., Barnier F., Mousseau T.A. (2012a). Ecosystems effects 25 years after Chernobyl : pollinators, fruit
set and recruitment. Oecologia, 170: 8-9:
Møller A.P., Bonisoli-Alquati A., Rudolfsen G., Mousseau T.A. (2011). Chernobyl Birds Have Smaller Brains. PLoS
ONE 6 (2): e16862
Møller A.P., Bonisoli-Alquati A., Rudolfsen G., Mousseau T.A. (2012b). Elevated mortality among birds in
Chernobyl as judged from biased sex and age ratios. PLoS One, 7(4): e35223.
doi:10.1371/journal.pone.0035223
Møller A.P., Bonisoli-Alquati A., Rudolfsen G., Mousseau, T.A. (2011). Chernobyl Birds Have Smaller Brains.
PLoS ONE 6 (2): e16862

7/8

March 2016
Møller A.P., Mousseau T.A. (2007a). Species richness and abundance of forest birds in relation to radiation at
Chernobyl. Biology Letters of the Royal Society, 3: 8-9: PDI
Møller A.P., Mousseau T.A. (2007b). Determinants of Interspecific Variation in Population Declines of Birds
after Exposure to Radiation at Chernobyl. Journal of Applied Ecology, 44: 8-9:
Møller A.P., Mousseau T.A. (2009). Reduced abundance of insects and spiders linked to radiation at Chernobyl
20 years after the accident. Biology Letters of the Royal Society 5(3): 8-9:
Møller A.P., Mousseau T.A. (2013). Assessing effects of radiation on abundance of mammals and predator-preyinteractions in Chernobyl using tracks in the snow. Ecological Indicators 26: 8-9:
Møller A.P., Surai P., Mousseau T.A. (2005). Antioxidants, radiation and mutation as revealed by sperm
abnormality in barn swallows from Chernobyl. Proc Biol Sci. 09/12/14 8-9:
Mousseau T.A., Møller A.P. (2013). Elevated Frequency of Cataracts in Birds from Chernobyl. PlosOne, 8, 7,
e66939.
Mousseau T.A., Welch S.M., Chizhevsky I., Bondarenko O., Milinevsky G., Tedeschi D.J., Bonisoli-Alquati A.,
Møller A.P. (2013). Tree rings reveal extent of exposure to ionizing radiation in Scots pine Pinus
sylvestris”. Trees, 27: 8-9:
Nohara C., Taira W., Hiyama A., Tanahara A., Takatsuji T., Otaki J.M. (2014). Ingestion of radioactively
contaminated diets for two generations in the pale grass blue butterfly. BMC Evolutionary Biology 14:193
Watanabe Y., Ichikawa S., Kubota M., Hoshino J., Kubota Y., Maruyama K., Fuma S., Kawaguchi I., Yoschenko
V.I., Yoshida S. (2015) Morphological defects in native Japanese fir trees around the Fukushima Daiichi
Nuclear Power Plant. SCM: Rep., 5, 13232; doi: + 33 (0)4 92 38 71 67
Yoschenko V.I., Kashparov V.A., Melnychuk M.D., Levchuk S.E., Bondar Y.O., Lazarev M., Yoschenko M.I.,
Farfan E.B., Jannik G.T. (2011) Chronic irradiation of scots pine trees (Pinus sylvestris) in the Chernobyl
exclusion zone: dosimetry and radiobiological effects. Health Physics, 101: 8-9:
Zelena L., Sorochinsky B., vonS Arnold, vanL Zyl, Clapham D.H. (2005) Indications of limited gene expression in
Pinus sylvestris trees from the Chernobyl region. Journal of Environmental Radioactivity, 84: 8-9:

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