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"Animals Effect of radioactive pollution on."
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Effects of environmental radiation on testes and spermatogenesis in wild large Japanese field mice (Apodemus speciosus) from Fukushima
The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident that occurred after the Great East Japan Earthquake in March 2011 released large quantities of radionuclides to the environment. The long-term effects of radioactive cesium (Cs) on biota are of particular concern. We investigated the accumulation of radioactive Cs derived from the FDNPP accident, and chronic effects of environmental radionuclides on male reproduction, in the large Japanese field mouse (
Apodemus speciosus
). In 2013 and 2014, wild mice were captured at 2 sites in Fukushima Prefecture and at 2 control sites that were distant from Fukushima. Although the median concentrations of
134
Cs and
137
Cs in the mice from Fukushima exceeded 4,000 Bq/kg, there were no significant differences in the apoptotic cell frequencies or the frequencies of morphologically abnormal sperm among the capture sites. Thus, we conclude that radiation did not cause substantial male subfertility in Fukushima during 2013 and 2014, and radionuclide pollution levels in the study sites would not be detrimental to spermatogenesis of the wild mice in Fukushima.
Journal Article
The biological impacts of the Fukushima nuclear accident on the pale grass blue butterfly
The collapse of the Fukushima Dai-ichi Nuclear Power Plant caused a massive release of radioactive materials to the environment. A prompt and reliable system for evaluating the biological impacts of this accident on animals has not been available. Here we show that the accident caused physiological and genetic damage to the pale grass blue
Zizeeria maha
, a common lycaenid butterfly in Japan. We collected the first-voltine adults in the Fukushima area in May 2011, some of which showed relatively mild abnormalities. The F
1
offspring from the first-voltine females showed more severe abnormalities, which were inherited by the F
2
generation. Adult butterflies collected in September 2011 showed more severe abnormalities than those collected in May. Similar abnormalities were experimentally reproduced in individuals from a non-contaminated area by external and internal low-dose exposures. We conclude that artificial radionuclides from the Fukushima Nuclear Power Plant caused physiological and genetic damage to this species.
Journal Article
Oxidative stress on the male reproductive organs of wild mice collected from an area contaminated by radioactive materials in Fukushima
The Fukushima Daiichi Nuclear Power Plant accident caused the release of large amounts of radioactive material into the environment. Radiation from radionuclides cause DNA lesions, mainly via oxidation, which adversely affect wild organisms by damaging their germ cells. Here, we investigated the effects of radiation on the reproductive organs of Japanese field mice (
Apodemus speciosus
) by estimating the dose rate of radiation exposure, the accumulation of DNA lesions, and the expression of DNA repair enzymes. In highly contaminated areas, mouse testes received a radiation dose rate > 0.1 mGy/d. According to the International Commission on Radiological Protection, there is a very low probability of effects in the reference rat species at this exposure level. The results of the current study do not definitively conclude that the expression of 8-oxoguanine DNA glycosylase 1 and superoxide dismutase in mouse testes increase with dose rate and lifetime dose. However, 8-hydroxy-2′-deoxyguanosine accumulation increases in a dose rate- and lifetime dose-dependent manner in mouse testes, but is not observed in the sperm of the cauda epididymis. These results suggest that, although DNA lesions occurred in male germ cells of Fukushima mice, most were successfully repaired by DNA repair enzymes at the observed gene expression level.
Journal Article
Radioactive contamination and climate warming affect physiological performance of Chornobyl barn swallows
Global warming and degradation of natural habitats are the two main factors causing ecophysiological stress on individuals and risk for biodiversity. Hyperthermia is a common response to stress in homeothermic animals, in particular to heat, pathogens and environmental contamination. Resilience of biological systems to global warming may be deteriorated in polluted habitats. Here we investigated how body temperature of a wild bird, the barn swallow ( Hirundo rustica ), responded to global warming while simultaneously exposed to radioactive contamination from the Chernobyl accident. Our results showed that both high air temperatures (t = 15.55, df = 335, p < 0.0001) and elevated environmental radioactive contamination (t = 5.18, df = 8.09, p = 0.0008) increased internal body temperature of individuals. The additive effect suggests that birds might suffer hyperthermia in locally contaminated habitat (1.47% body temperature increase) while simultaneously exposed to globally rising temperatures (1.95% body temperature increase), potentially reducing the fitness of individual and the maintenance of breeding colonies. The cumulative and interactive negative effects of multiple stressors, such as those emerging from increasing habitat degradation and climate change, will likely contribute to biodiversity losses globally.
Journal Article
Human health risk assessment due to consumption of dried fish in Chennai, Tamil Nadu, India: a baseline report
The current study sought to determine the levels of radioactivity and heavy metal contamination in 22 dried fish samples collected in Chennai, Tamil Nadu. The study found that there were substantial heavy metals concentrations for Pb, Mn, Cr, Co, and Cd. The concentration of heavy metal Pb being alarmingly high (32.85 to 42.09 mg/kg), followed by Cd (2.18 mg/kg to 3.51 mg/kg) than the permissible limit of WHO (2.17 mg/kg) for Pb and (0.05 mg/kg) for Cd. In terms of radioactivity, the gross alpha activity in the dried fish samples ranged 6.25 ± 0.12 to 48.21 ± 0.11 Bg/kg with an average of 20.35 Bg/kg and with a gross beta activity from 6.48 ± 0.02 to 479.47 ± 0.65 Bg/kg, for an average of 136.83 Bg/kg. The study found that the internal radiation dose that people receive upon consuming the fish species
Sphyraena obtusata
,
Rachycentron canadum
,
Lepidocephalichthys thermalis
,
Synodontidae
,
Carangoides malabaricus
,
Sardina pilchardus
,
Scomberomorus commerson
,
Sillago sihama
,
Gerres subfasciatus
, and
Amblypharyngodon mola
is above the ICRP-recommended limit of less than 1 mSv/year. Annual gonadal dose equivalent (AGDE) and total excessive lifetime cancer risk (ELCR) ranged 0.488 µSv year
−1
and 0.004 µSv year
−1
respectively, the values of AGDE being higher than the global average value. The findings of the study indicate that the analyzed dried fish samples are contaminated with Pb and Cd, which shall pose cancer risk to the consumers as a result.
Journal Article
Population transcriptogenomics highlights impaired metabolism and small population sizes in tree frogs living in the Chernobyl Exclusion Zone
Background
Individual functional modifications shape the ability of wildlife populations to cope with anthropogenic environmental changes. But instead of adaptive response, human-altered environments can generate a succession of deleterious functional changes leading to the extinction of the population. To study how persistent anthropogenic changes impacted local species’ population status, we characterised population structure, genetic diversity and individual response of gene expression in the tree frog
Hyla orientalis
along a gradient of radioactive contamination around the Chernobyl nuclear power plant.
Results
We detected lower effective population size in populations most exposed to ionizing radiation in the Chernobyl Exclusion Zone that is not compensated by migrations from surrounding areas. We also highlighted a decreased body condition of frogs living in the most contaminated area, a distinctive transcriptomics signature and stop-gained mutations in genes involved in energy metabolism. While the association with dose will remain correlational until further experiments, a body of evidence suggests the direct or indirect involvement of radiation exposure in these changes.
Conclusions
Despite ongoing migration and lower total dose rates absorbed than at the time of the accident, our results demonstrate that
Hyla orientalis
specimens living in the Chernobyl Exclusion Zone are still undergoing deleterious changes, emphasizing the long-term impacts of the nuclear disaster.
Journal Article
Radioactive contamination in feral dogs in the Chernobyl exclusion zone: Population body-burden survey and implications for human radiation exposure
This report describes a two-year effort to survey the internal
137
Cs and external
β
-emitter contamination present in the feral dog population near the Chernobyl nuclear power plant (ChNPP) site, and to understand the potential for human radiation exposure from this contamination. This work was performed as an integral part of the radiation safety and control procedures of an animal welfare oriented trap-neuter-release (TNR) program. The measurement program focused on external contamination surveys using handheld
β
-sensitive probes, and internal contamination studies using a simple whole-body counter. Internal
137
Cs
burden was measured non-invasively during post-surgical observation and recovery. External
β
contamination surveys performed during intake showed that 21/288 animals had significant, removable external contamination, though not enough to pose a large hazard for incidental contact. Measurements with the whole-body counter indicated internal
137
Cs body burdens ranging from undetectable (minimum detection level ∼100 Bq/kg in 2017, ∼30 Bq/kg in 2018) to approximately 30,000 Bq/kg. A total of 33 animals had
137
Cs body-burdens above 1 kBq/kg, though none posed an external exposure hazard. The large variation in the
137
Cs
concentration in these animals is not well-understood, could be due to prey selection, access to human food scraps, or extended residence in highly contaminated areas. The small minority of animals with external contamination may pose a contamination risk allowing exposures in excess of regulatory standards.
Journal Article
Highly reduced mass loss rates and increased litter layer in radioactively contaminated areas
The effects of radioactive contamination from Chernobyl on decomposition of plant material still remain unknown. We predicted that decomposition rate would be reduced in the most contaminated sites due to an absence or reduced densities of soil invertebrates. If microorganisms were the main agents responsible for decomposition, exclusion of large soil invertebrates should not affect decomposition. In September 2007 we deposited 572 bags with uncontaminated dry leaf litter from four species of trees in the leaf litter layer at 20 forest sites around Chernobyl that varied in background radiation by more than a factor 2,600. Approximately one quarter of these bags were made of a fine mesh that prevented access to litter by soil invertebrates. These bags were retrieved in June 2008, dried and weighed to estimate litter mass loss. Litter mass loss was 40 % lower in the most contaminated sites relative to sites with a normal background radiation level for Ukraine. Similar reductions in litter mass loss were estimated for individual litter bags, litter bags at different sites, and differences between litter bags at pairs of neighboring sites differing in level of radioactive contamination. Litter mass loss was slightly greater in the presence of large soil invertebrates than in their absence. The thickness of the forest floor increased with the level of radiation and decreased with proportional loss of mass from all litter bags. These findings suggest that radioactive contamination has reduced the rate of litter mass loss, increased accumulation of litter, and affected growth conditions for plants.
Journal Article
Chernobyl Birds Have Smaller Brains
Animals living in areas contaminated by radioactive material from Chernobyl suffer from increased oxidative stress and low levels of antioxidants. Therefore, normal development of the nervous system is jeopardized as reflected by high frequencies of developmental errors, reduced brain size and impaired cognitive abilities in humans. Alternatively, associations between psychological effects and radiation have been attributed to post-traumatic stress in humans.
Here we used an extensive sample of 550 birds belonging to 48 species to test the prediction that even in the absence of post-traumatic stress, there is a negative association between relative brain size and level of background radiation. We found a negative association between brain size as reflected by external head volume and level of background radiation, independent of structural body size and body mass. The observed reduction in brain size in relation to background radiation amounted to 5% across the range of almost a factor 5,000 in radiation level. Species differed significantly in reduction in brain size with increasing background radiation, and brain size was the only morphological character that showed a negative relationship with radiation. Brain size was significantly smaller in yearlings than in older individuals.
Low dose radiation can have significant effects on normal brain development as reflected by brain size and therefore potentially cognitive ability. The fact that brain size was smaller in yearlings than in older individuals implies that there was significant directional selection on brain size with individuals with larger brains experiencing a viability advantage.
Journal Article