RESUMEN
The visual system is an important biological indicator of effects induced by ultraviolet (UV) radiation. However, research has extensively investigated the effects of high-dose UV radiation in a single exposure, thus, the differential of this work was to investigate the effects of UVB radiation in low doses in single and repeated exposure. Therefore, we investigated the effects of repeated exposure to environmental UVB doses (0.09 J/cm2) on the retina and optic lobes of the crab Neohelice granulata. We evaluated the reactive oxygen species (ROS) concentration, antioxidant capacity against peroxyl radicals (ACAP) levels, catalase (CAT) and glutathione S-transferase (GST) activities and lipoperoxidation (LPO) levels and performed histological analysis. The crabs were exposed to UVB radiation for 1 or 60 days, while the control group was exposed to visible light. In the retina region, increases in ROS concentration and CAT and GST activities after the single exposure were observed. After 60 days of exposure, we observed an increase in ACAP levels. In the optic lobes, we observed an increase in GST activity and a decrease in LPO levels after the single exposure. However, we observed an increase in ROS concentration after 60 days of exposure. Moreover, after 60 days of exposure, infiltrating hemocytes in the retina and disorganization in neuron cell bodies of the external medulla were observed. In this sense, single and repeated exposure to low doses of UVB radiation induced changes in oxidative status and inflammatory process in the visual system of the crab Neohelice granulata.
Asunto(s)
Crustáceos/efectos de la radiación , Rayos Ultravioleta , Visión Ocular/efectos de la radiación , Animales , Crustáceos/fisiología , Relación Dosis-Respuesta en la Radiación , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Crude oils are composed of an assortment of hydrocarbons, some of which are polycyclic aromatic hydrocarbons (PAHs). Polycyclic aromatic hydrocarbons are of particular interest due to their narcotic and potential phototoxic effects. Several studies have examined the phototoxicity of individual PAHs and fresh and weathered crude oils, and several models have been developed to predict PAH toxicity. Fingerprint analyses of oils have shown that PAHs in crude oils are predominantly alkylated. However, current models for estimating PAH phototoxicity assume toxic equivalence between unsubstituted (i.e., parent) and alkyl-substituted compounds. This approach may be incorrect if substantial differences in toxic potency exist between unsubstituted and substituted PAHs. The objective of the present study was to examine the narcotic and photo-enhanced toxicity of commercially available unsubstituted and alkylated PAHs to mysid shrimp (Americamysis bahia). Data were used to validate predictive models of phototoxicity based on the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap approach and to develop relative effect potencies. Results demonstrated that photo-enhanced toxicity increased with increasing methylation and that phototoxic PAH potencies vary significantly among unsubstituted compounds. Overall, predictive models based on the HOMO-LUMO gap were relatively accurate in predicting phototoxicity for unsubstituted PAHs but are limited to qualitative assessments. Environ Toxicol Chem 2017;36:2043-2049. © 2017 SETAC.
Asunto(s)
Crustáceos/efectos de los fármacos , Modelos Teóricos , Petróleo/toxicidad , Hidrocarburos Policíclicos Aromáticos/toxicidad , Rayos Ultravioleta/efectos adversos , Alquilación , Animales , Crustáceos/efectos de la radiación , Monitoreo del Ambiente , Dosificación Letal Mediana , Luz/efectos adversos , Nivel sin Efectos Adversos Observados , Hidrocarburos Policíclicos Aromáticos/química , Relación Estructura-Actividad , Estupor/inducido químicamente , Análisis de SupervivenciaRESUMEN
We investigated the effects of γ-irradiation on the survival of resting eggs of the cladoceran Moina macrocopa and on the parameters of the life cycle of neonates hatched from the irradiated eggs. It was shown that γ-irradiation in a wide range of doses (from the background level to 100 Gy) had no effect on survival of eggs and mortality of neonates hatched from the irradiated eggs. However, exceeding the absorbed dose of 40 Gy sharply decreased the reproductive potential of the neonates hatched from irradiated eggs.
Asunto(s)
Crustáceos/efectos de la radiación , Rayos gamma , Estadios del Ciclo de Vida/efectos de la radiación , Óvulo/efectos de la radiación , Animales , Crustáceos/crecimiento & desarrolloRESUMEN
Significant increases in toxicity have been observed as a result of polycyclic aromatic hydrocarbon (PAH) absorption of ultraviolet (UV) radiation in aquatic organisms. Early life stage aquatic organisms are predicted to be more susceptible to PAH photo-enhanced toxicity as a result of their translucence and tendency to inhabit shallow littoral or surface waters. The objective of the present study was to evaluate the sensitivity of varying ages of larval mysid shrimp (Americamysis bahia), inland silverside (Menidia beryllina), sheepshead minnow (Cyprinodon variegatus), and Gulf killifish (Fundulus grandis) to photo-enhanced toxicity and to examine the correlation between photo-enhanced toxicity and organism pigmentation. Organisms were exposed to fluoranthene and artificial UV light at different larval ages and results were compared using median lethal concentrations (LC50s) and the lethal time-to-death (LT50s). In addition, a high UV light intensity, short-duration (4-h) experiment was conducted at approximately 24 W/m(2) of ultraviolet radiation A (UV-A) and compared with a low-intensity, long-duration (12-h) experiment at approximately 8 W/m(2) of UV-A. The results indicated decreased toxicity with increasing age for all larval organisms. The amount of organism pigmentation was correlated with observed LC50 and LT50 values. High-intensity short-duration exposure resulted in greater toxicity than low-intensity long-duration UV treatments for mysid shrimp, inland silverside, and sheepshead minnow. Data from these experiments suggest that toxicity is dependent on age, pigmentation, UV light intensity, and fluoranthene concentration.
Asunto(s)
Organismos Acuáticos/efectos de los fármacos , Organismos Acuáticos/efectos de la radiación , Fluorenos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Organismos Acuáticos/fisiología , Crustáceos/efectos de los fármacos , Crustáceos/fisiología , Crustáceos/efectos de la radiación , Cyprinidae , Fundulidae , Golfo de México , Larva/efectos de los fármacos , Larva/fisiología , Larva/efectos de la radiación , Dosificación Letal Mediana , México , Pigmentación/efectos de los fármacos , Pigmentación/efectos de la radiación , Smegmamorpha , Rayos Ultravioleta/efectos adversosRESUMEN
Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive. Current phyla-specific dose levels and limits proposed by major regulatory bodies were found to be inadequate to protect species across a range of endpoints including morbidity, mutation and reproduction and examples are discussed within. These findings serve to prioritise areas for future research that will significantly advance understanding of radiation-induced effects in aquatic invertebrates and consequently enhance ability to predict the impacts of radioactive releases on the environment.
Asunto(s)
Crustáceos/efectos de la radiación , Radiación Ionizante , Contaminantes Radiactivos del Agua/toxicidad , AnimalesRESUMEN
A radiation-resistant bacterial isolate from gamma-radiation-processed (5 kGy) semidried prawns was identified as a new strain of Macrococcus caseolyticus and was designated as M. caseolyticus (A) on the basis of morphological and biochemical characterization and 16S rRNA sequencing. DNA-DNA hybridization studies with M. caseolyticus DSM 20597(T) further confirmed the isolate as M. caseolyticus. Major fatty acids present in M. caseolyticus (A) were C14:0, C16:1ω11c, and C18:1ω9c, whereas C15:0anteiso, C16:0iso, and C18:0iso were absent. The closest match for the isolate, as per fatty acid methyl ester analysis, was M. caseolyticus DSM 20597(T). However, the similarity index was significantly low (0.112), which indicates that the isolate could be a new strain of M. caseolyticus. The decimal reduction dose (D10) for M. caseolyticus (A), M. caseolyticus JCSC5402, and Staphylococcus aureus MTCC96 was 1.18, 0.607, and 0.19 kGy, respectively. This is the first report on radiation resistance of M. caseolyticus. Macrococcus caseolyticus (A) is more resistant to gamma and UV radiation stress than are M. caseolyticus JCSC5402 and S. aureus MTCC96; however, it is sensitive to heat as well as desiccation stress.
Asunto(s)
Crustáceos/microbiología , Mariscos/microbiología , Staphylococcaceae/aislamiento & purificación , Staphylococcaceae/efectos de la radiación , Animales , Crustáceos/efectos de la radiación , Ácidos Grasos/análisis , Ácidos Grasos/metabolismo , Irradiación de Alimentos , Rayos gamma , Filogenia , Mariscos/efectos de la radiación , Staphylococcaceae/genética , Staphylococcaceae/metabolismoRESUMEN
Using new collecting techniques with the Johnson-Sea-Link submersible, eight species of deep-sea benthic crustaceans were collected with intact visual systems. Their spectral sensitivities and temporal resolutions were determined shipboard using electroretinography. Useable spectral sensitivity data were obtained from seven species, and in the dark-adapted eyes, the spectral sensitivity peaks were in the blue region of the visible spectrum, ranging from 470 to 497 nm. Under blue chromatic adaptation, a secondary sensitivity peak in the UV portion of the spectrum appeared for two species of anomuran crabs: Eumunida picta (λ(max)363 nm) and Gastroptychus spinifer (λ(max)383 nm). Wavelength-specific differences in response waveforms under blue chromatic adaptation in these two species suggest that two populations of photoreceptor cells are present. Temporal resolution was determined in all eight species using the maximum critical flicker frequency (CFF(max)). The CFF(max) for the isopod Booralana tricarinata of 4 Hz proved to be the lowest ever measured using this technique, and suggests that this species is not able to track even slow-moving prey. Both the putative dual visual pigment system in the crabs and the extremely slow eye of the isopod may be adaptations for seeing bioluminescence in the benthic environment.
Asunto(s)
Crustáceos/fisiología , Crustáceos/efectos de la radiación , Ecosistema , Luz , Mediciones Luminiscentes , Océanos y Mares , Visión Ocular/efectos de la radiación , Animales , Bahamas , Crustáceos/clasificación , Adaptación a la Oscuridad/efectos de la radiación , Electrorretinografía , Células Fotorreceptoras de Invertebrados/fisiología , Células Fotorreceptoras de Invertebrados/efectos de la radiación , Especificidad de la Especie , Manejo de Especímenes , Factores de Tiempo , Grabación en Video , Visión Ocular/fisiologíaRESUMEN
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: (239)Pu, (106)Ru and (95)Zr (crustacean), (54)Mn, (90)Sr, (95)Nb, (106)Ru, (137)Cs (239)Pu, (241)Am and natural U (molluscs), and (54)Mn, (90)Sr, (137)Cs and (144)Ce (fish) are in good agreement with those previously published, whilst for some of them, in particular, for (32)P and (110)Ag (crustaceans), (35)S (molluscs), (32)P, (35)S, (95)Nb, and (106)Ru (macroalgae) and (60)Co and (239,240)Pu (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.
Asunto(s)
Monitoreo del Ambiente/métodos , Radioisótopos/metabolismo , Contaminantes Radiactivos del Agua/análisis , Animales , Biodiversidad , Crustáceos/efectos de la radiación , Ecosistema , Peces , Contaminación Radiactiva de Alimentos , Agua Dulce/análisis , Lenguaje , Biología Marina , Moluscos/efectos de la radiación , Federación de Rusia , Agua de Mar/análisis , Factores de Tiempo , Movimientos del AguaRESUMEN
Embryonic development of the Asian tadpole shrimp Triops granarius is arrested at an early stage of organogenesis under darkness, whereas exposure to light resumes its development and promotes hatching. To better understand the photoreception systems involved in the light-induced hatching of T. granarius eggs, we examined the spectral sensitivity of hatching and the expression of genes involved in photoreception (opsins) and phototransduction (arrestin 2). Hatching of eggs is induced by light of broad wavelengths, from ultraviolet (UV) (395 nm) to red (660 nm), suggesting that visual pigments are involved in photoreception. Next, we focused on opsins which are protein moieties of visual pigments and arrestin 2 which is involved in a phototransduction cascade. Transcripts of several opsin genes and the arrestin 2 gene were detected in T. granarius eggs. Thus, we present a possibility that T. granarius eggs use visual pigments for light perception in light-induced hatching.
Asunto(s)
Crustáceos/genética , Crustáceos/efectos de la radiación , Fototransducción/genética , Fototransducción/efectos de la radiación , Luz , Óvulo/crecimiento & desarrollo , Óvulo/efectos de la radiación , Secuencia de Aminoácidos , Animales , Arrestinas/genética , Crustáceos/crecimiento & desarrollo , Larva/genética , Larva/crecimiento & desarrollo , Larva/metabolismo , Larva/efectos de la radiación , Datos de Secuencia Molecular , Opsinas/genética , Óvulo/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y Especificidad , Alineación de Secuencia , beta-ArrestinasRESUMEN
Criteria are needed to be able to judge the level of risk associated with dose rates estimated for non-human biota. In this paper, European guidance on the derivation of predicted no-effect chemical concentrations has been applied to appropriate radiation sensitivity data. A species sensitivity distribution fitted to the data for all species resulted in a generic predicted no-effect dose rate of 10 microGy h(-1).Currently, data are inadequate to derive screening values for separate organism groups. A second, higher, benchmark could aid in decision making by putting results into context on the scale of no effect to a risk of 'serious' effect. The need for, meaning and use of such a value needs to be debated by the wider community. This paper explores potential approaches of deriving scientific input to this debate. The concepts proposed in this paper are broadly consistent with the framework for human protection.
Asunto(s)
Conservación de los Recursos Naturales/métodos , Monitoreo del Ambiente/legislación & jurisprudencia , Monitoreo del Ambiente/normas , Protección Radiológica/legislación & jurisprudencia , Protección Radiológica/normas , Radiación Ionizante , Animales , Aves , Crustáceos/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Ecología , Ecosistema , Europa (Continente) , Mamíferos , Moluscos/efectos de la radiación , Plantas/efectos de la radiación , Medición de RiesgoRESUMEN
This paper analyzes the influence of infrared radiation (IR) on regeneration, after autotomy of limb buds of Neohelice granulata and consequently the time molt. Eyestalks were ablated to synchronize the start of molt. Afterward, animals were autotomized of five pereopods and divided into control and irradiated groups. The irradiated group was treated for 30 min daily until molt. Limb buds from five animals of days 4, 16 and 20 were collected and histological sections were made from them. These sections were photographed and chitin and epithelium content measured. Another group was made, and after 15 days limb buds were extracted to analyze mitochondrial enzymatic activity from complex I and II. The irradiated group showed a significant reduction in molt time (19.38+/-1.22 days) compared with the control group (32.69+/-1.57 days) and also a significant increase in mitochondrial complex I (388.9+/-27.94%) and II (175.63+/-7.66%) in the irradiated group when compared with the control group (100+/-17.90; 100+/-7.82, respectively). However, these effects were not accompanied by histological alterations in relation to chitin and epithelium. This way, it was possible to demonstrate that IR increases complex I and II activity, reduces the time molt and consequently increases the appendage regeneration rate.
Asunto(s)
Crustáceos/efectos de la radiación , Rayos Infrarrojos , Muda , Regeneración , Animales , Crustáceos/fisiología , Esbozos de los Miembros/crecimiento & desarrollo , Esbozos de los Miembros/fisiología , Esbozos de los Miembros/efectos de la radiaciónRESUMEN
BACKGROUND: The beating or fanning movements of three pairs of maxilliped flagella in crabs and crayfish modify exhalent gill currents while drawing water over chemoreceptors on the head. They play an integral part both in signalling by distributing urine odours, and in active chemosensation. RESULTS: The rhythmical maxilliped movements start with maxilliped 3 followed after a delay of 15 to 20 ms in shore crabs by maxilliped 2 and then maxilliped 1, at a frequency of 18 to 20 Hz in crabs and 10 to 13 Hz in signal crayfish. The contraction of a single abductor muscle controls the power stroke (abduction) of each flagellum, which is accompanied by flaring of feather-like setae which increase its surface area. No muscle can bring about the return stroke (adduction). Release of an isolated flagellum from an imposed abduction is followed by a rapid recoil to its resting adducted position. The relationship between the extent of abduction and the angular velocity of the return stroke indicates the operation of a spring. Blue fluorescence under UV light, and its dependence on the pH of the bathing medium, indicates that resilin is present at the joint between an exopodite and flagellum, at the annuli of a flagellum and at the base of the setae. CONCLUSION: Resilin is progressively bent as a flagellum is abducted and resumes its natural shape when the joint recoils. Other distortions of the exopodites may also contribute to this spring-like action. The joint is therefore controlled by a single abductor muscle operating against a spring in which the elastic properties of resilin play a key role.
Asunto(s)
Crustáceos/fisiología , Extremidades/fisiología , Proteínas de Insectos/metabolismo , Articulaciones/fisiología , Movimiento/fisiología , Contracción Muscular , Músculos/fisiología , Animales , Crustáceos/efectos de la radiación , Conductividad Eléctrica , Extremidades/efectos de la radiación , Flagelos/fisiología , Flagelos/efectos de la radiación , Fluorescencia , Articulaciones/efectos de la radiación , Movimiento/efectos de la radiación , Músculos/efectos de la radiación , Rayos UltravioletaRESUMEN
The important role of direct action of a constant magnetic field (CMF) on a fabric of a brain in its realization neural-effects under condition of an irradiation of a head of an animal is shown. In experiments on rabbits it is statistically proved, that a various degree of neural isolation of a bark of a brain, not only does not interfere with display of reaction of its bioelectric activity on CMF, but also does by its more precise (unequivocal, intensive, short-latent), in comparison with corresponding answers of intact brain. The comparative analysis of bioelectric activity of intact brain, a preparation "cerveau isole", the neural-isolated strip of a bark (at rabbits) and completely isolated nervous system (a chain of a river cancer) in conditions of action CMF proves the above-stated position.
Asunto(s)
Encéfalo/efectos de la radiación , Campos Electromagnéticos/efectos adversos , Animales , Encéfalo/fisiología , Crustáceos/fisiología , Crustáceos/efectos de la radiación , Ganglios de Invertebrados/efectos de la radiación , Magnetismo , Masculino , Neuronas/fisiología , Neuronas/efectos de la radiación , Conejos , Mariscos/efectos de la radiaciónRESUMEN
Coelomomyces utahensis is a fungal parasite of several genera of mosquitoes that inhabit rock-pools in southern Utah. Studies of the biology of Coelomomyces and their potential use in biological control of mosquitoes have been hindered by their complex life history, lack of axenic culture methods, and logistical problems producing their arthropod hosts for in vivo culture. In the case of C. utahensis, we have identified the alternate microcrustacean host as Potamocypris unicaudata, which is an ostracod that can be easily reared in abundance and stored for long periods. Described here are the life cycle and culturing of C. utahensis.
Asunto(s)
Coelomomyces/crecimiento & desarrollo , Técnicas Microbiológicas , Aedes/parasitología , Animales , Crustáceos/microbiología , Crustáceos/fisiología , Crustáceos/efectos de la radiación , Luz , UtahRESUMEN
Irradiation is one of the most important and effective methods towards food preservation despite the consumer lack of trust and aversion towards this method. Irradiation effectiveness greatly depends on the dose provided to food. This review aims at summarizing all available information regarding the impact of irradiation dose on the shelf life and microflora and sensory and physical properties of fish, shellfish, molluscs, and crustaceans. The synergistic effect of irradiation in conjunction with other techniques such as salting, smoking, freezing, and vacuum packaging was also reported. Another issue covered within the frame of this review is the detection (comparison of methods in terms of their effectiveness and validity) of irradiated fish and seafood. The information related to fish and seafood irradiation and its detection is presented by means of 11 comprehensive tables and 9 figures.
Asunto(s)
Peces , Irradiación de Alimentos , Alimentos Marinos , Animales , Crustáceos/química , Crustáceos/microbiología , Crustáceos/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Peces/microbiología , Conservación de Alimentos/métodos , Control de Calidad , Alimentos Marinos/análisis , Alimentos Marinos/microbiología , Alimentos Marinos/efectos de la radiación , Sensación , Mariscos/análisis , Mariscos/microbiología , Mariscos/efectos de la radiación , Especificidad de la Especie , Factores de TiempoRESUMEN
Lake Baikal, in Siberia, Russia, contains the highest biodiversity of any extant lake, including an impressive radiation of gammaroidean amphipods that are often cited as a classic case of adaptive radiation. However, relationships among Baikal's amphipods remain poorly understood. The phylogenetic history of 32 Lake Baikal amphipod species, representing most major lineages of the endemic fauna, was examined using three genes (COI, 16S rRNA, and 18S rRNA), and 152 morphological characters. Results support monophyly of the largest and most diverse of the Baikalian families, the Acanthogammaridae. Analyses suggest that a second Baikalian family, the fossorial Micruropodidae, is paraphyletic and composed of two divergent clades, one of which includes Macrohectopus branickii, a morphologically specialized pelagic planktivore traditionally assigned its own family. The extreme morphological and ecological divergence of Macrohectopus from its close genetic relatives, and conversely, the large genetic distances among other morphologically similar micruropodids, suggest that morphological and molecular evolution have often been uncoupled during the radiation of Baikal's amphipods. This study suggests that the amphipod fauna of Lake Baikal is polyphyletic; originating from two independent invasions of the lake.
Asunto(s)
Evolución Biológica , Crustáceos/genética , Crustáceos/efectos de la radiación , Evolución Molecular , Plantas/genética , Plantas/efectos de la radiación , Animales , Biodiversidad , Crustáceos/clasificación , Fósiles , Agua Dulce , Plantas/clasificación , ARN Ribosómico 16S/genética , ARN Ribosómico 18S/genética , SiberiaRESUMEN
Electrical currents in underwater sea cables could induce magnetic fields. The sea cables lie on or within the sea bottom and this is the living area for many invertebrate and vertebrate species. North Sea prawn Crangon crangon (Crustacea, Decapoda), round crab Rhithropanopeus harrisii (Crustacea, Brachyura), glacial relict isopod Saduria entomon (Crustacea, Isopoda), blue mussel Mytilus edulis (Bivalvia), and young flounder Plathichthys flesus (Pisces) were exposed to a static magnetic field (MF) of 3.7 mT for several weeks. The results showed no differences in survival between experimental and control animals. Mussels M. edulis were kept under static magnetic field conditions for 3 months during their reproductive period in spring. The determination of gonad index and condition index revealed no significant differences to the control group.
Asunto(s)
Bivalvos/efectos de la radiación , Crustáceos/efectos de la radiación , Campos Electromagnéticos , Exposición a Riesgos Ambientales , Lenguado , Magnetismo , Animales , Reproducción/efectos de la radiación , Tasa de Supervivencia , Factores de TiempoRESUMEN
The study was done to investigate the content of manmade radionuclides in aquatic organisms of the Yenisei River near the Mining-and-Chemical Combine (MCC) and to estimate the exposure dose rates to organisms from various sources. The results of the investigation and calculations suggest that the main source of radioactive contamination of aquatic organisms is the coolant of the third MCC reactor, which is still being released into the Yenisei. Gamma-spectrometric analysis revealed 23 manmade radionuclides in the biomass of aquatic plants. The aquatic animal Phylolimnogammarus viridis and diatoms also contain manmade radionuclides. Among aquatic organisms, the highest dose rate is received by aquatic plants (up to 39 microGy/day). For most aquatic organisms under study, the dose received from the technogenic irradiation is an order of magnitude higher than the dose received from natural irradiation. The water moss (Fontinalis antipyretica) features the highest capacity to accumulate manmade radionuclides; hence, it accumulates the largest technogenic exposure dose among the study aquatic organisms.
Asunto(s)
Industria Química , Monitoreo del Ambiente/métodos , Minería , Contaminación del Agua , Animales , Crustáceos/efectos de la radiación , Diatomeas/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Agua Dulce , Residuos Industriales , Plantas/efectos de la radiación , Radioisótopos/análisis , Siberia , Contaminantes Radiactivos del Agua/análisisRESUMEN
A dose per unit concentration database has been generated for application to ecosystem assessments within the FASSET framework. Organisms are represented by ellipsoids of appropriate dimensions, and the proportion of radiation absorbed within the organisms is calculated using a numerical method implemented in a series of spreadsheet-based programs. Energy-dependent absorbed fraction functions have been derived for calculating the total dose per unit concentration of radionuclides present in biota or in the media they inhabit. All radionuclides and reference organism dimensions defined within FASSET for marine and freshwater ecosystems are included. The methodology has been validated against more complex dosimetric models and compared with human dosimetry based on ICRP 72. Ecosystem assessments for aquatic biota within the FASSET framework can now be performed simply, once radionuclide concentrations in target organisms are known, either directly or indirectly by deduction from radionuclide concentrations in the surrounding medium.
Asunto(s)
Biología Marina , Dosis de Radiación , Radiobiología , Animales , Bacterias/efectos de la radiación , Aves , Crustáceos/efectos de la radiación , Eucariontes/efectos de la radiación , Peces , Mamíferos , Modelos Biológicos , Moluscos/efectos de la radiación , Plancton/efectos de la radiación , RadioisótoposRESUMEN
A framework for protection of the environment is likely to require a methodology for assessing dose rates arising from naturally occurring radionuclides. This paper addresses this issue for European aquatic environments through a process of (a) data collation, mainly with respect to levels of radioactivity in water sediments and aquatic flora and fauna, (b) the use of suitable distribution coefficients, concentration factors and global data where data gaps are present and (c) the utilisation of a reference organism approach whereby a finite number of suitable geometries are selected to allow dose per unit concentration factors to be derived and subsequent absorbed dose calculations (weighted or unweighted) to be made. The majority of the calculated absorbed dose, for both marine and freshwater organisms, arises from internally incorporated alpha emitters, with 210Po and 226Ra being the major contributors. Calculated doses are somewhat higher for freshwater compared to marine organisms, and the range of doses is also much greater. This reflects both the much greater variability of radionuclide concentrations in freshwater as compared to seawater, and also variability or uncertainty in concentration factor values. This work has revealed a number of substantial gaps in published empirical data especially for European aquatic environments.