Marina Vaghi

The fate of plutonium, 241 Am, 90 Sr and 137 Cs in the Antarctic ecosystem

A radioecological survey around Terra Nova Bay showed that 239 + 240Pu, 238Pu, 241Am, 90Sr and 137Cs activities were detectable in nearly all the samples. The 239 + 240Pu and 241Am concentrations in seawater were slightly lower than those in the northern Pacific Ocean. The activity level of 239 + 240Pu, 241Am and 137Cs in Antarctic sediments (Ross Sea) was c. 5–20 times lower than in northern Adriatic sediments (Mediterranean Sea), but the 238Pu activities were relatively high. The 90Sr concentrations in all the sediment samples from both the Ross and Adriatic seas tended to be low which might be due to an easier exchange of 90Sr in seawater. On the other hand, high concentrations were detected in Antarctic mosses, lichens and algae and their activity levels are comparable to those in central Italy. The radionuclide ratio analyses show that the major part of 239 + 240Pu, 241Am, 90Sr and 137Cs is the result of nuclear weapon tests. A higher 241Am/239 + 240Pu ratio might be due to the fallout of earlier atmospheric nuclear tests. The 238Pu239 + 240Pu ratio in the Antarctic matrices is about seven times higher than in the Northern Hemisphere and this could suggest that the major part of 238Pu originated from the SNAP-9A satellite accident.

Serotonin Transporter Role in Identifying Similarities Between SIDS and Idiopathic ALTE

OBJECTIVE: Considering previous genetic studies on sudden infant death syndrome (SIDS) and the role of L/L serotonin transporter (5HTT) genotype and correlated genes monoamine oxidase A (MAOA) and dopamine transporter (DAT) in unexpected death, an investigation was carried out verifying their involvement in apparent life-threatening events (ALTE and idiopathic form [IALTE]), also assessing common molecular basis with SIDS. METHODS: Differential diagnoses in 76 ALTE infants, distinguishing ALTE from IALTE was elaborated by using clinical-diagnostic data. Genotypes/allelic frequencies of DAT, MAOA, and 5HTT were determined in ALTE and IALTE infants and compared with data obtained from 20 SIDS and 150 controls. RESULTS: No association was found between DAT polymorphisms and ALTE/IALTE groups either at the genotype or allelic level (P range .11–.94). MAOA genotypes and allele data comparison between ALTE and controls was not significant; IALTE data showed a tendency for genotypes (P = .09) and were statistically significant for alleles (P = .036); however, MAOA significance disappeared once the Bonferroni correction was applied. 5HTT polymorphisms in IALTE remarked the role of L/L genotype (P < .00001) and L (P < .00001), as previously demonstrated in SIDS. CONCLUSIONS: Considering correspondence between 5HTT and MAOA in IALTE and SIDS, we hypothesize that the 2 syndromes are different expressions of a common ethiopathogenesis. In particular, genetic data suggest SIDS events could derive from IALTE episodes occurred during sleep, and therefore out of parental control. Despite its functional role, results highlight the usefulness of 5HTT as a valuable tracer of SIDS risk in IALTE infants. Owing to the small sample size, the results are to be considered preliminary and should be reevaluated in an independent sample.

Italian Antarctic Research Program: Environmental radioactivity survey around the Italian base (1987–1991) Terra Nova Bay — Ross sea region

Investigations have been carried out by the Italian Antarctic Research Program to determine the natural and artificial radioactivity levels of both the marine and terrestrial environments. Also, natural and anthropogenic fluxes of aerosol particles onto the Antarctic surface have been examined.

Radioactive and Stable Isotopes in Abiotic and Biotic Components of Antarctic Ecosystems Surrounding the Italian Base

Abstract Results concerning the analysis of natural (K-40, Th-232, U-238) and anthropogenic (Sr-90. Cs-137, Pu-238, Pu-239, 240) radioactivity determined in samples collected during the PNRA (National Program for Antarctic Research) 1990–91 and 1991–92 Scientific Expeditions, are presented. The data refer to samples of the terrestrial, lacustrine and marine ecosystems surrounding the Italian Base in the Terra Nova Bay (Ross Sea) territory with special emphasis on the Cs-137 biogeochemical behaviour. In particular, the role of the organic substance in the radionuclide transfer has been evaluated through statistical correlation analysis between the Cs-137 concentrations and organic matter, organic carbon and nitrogen contents determined in samples of marine and lacustrine sediments.

Molecular Barcoding of an Atypical Cyprinid Population Assessed by Cytochrome b Gene Sequencing

A fish population of the carp family Cyprinidae with atypical phenotypic characteristics was observed in one of the main catchments of the Pollino National Park, a valuable, protected area in southern Italy. In this area, the Italian roach Rutilus rubilio (Bonaparte, 1837), a native endemic fish of Tyrrhenean regions, has been introduced in sympatric conditions with Squalius squalus (Bonaparte, 1837) and Telestes muticellus (Bonaparte, 1837). A molecular investigation was carried out to assess the genetic identity of the population with a view to conservation. Direct sequencing of a cytochrome b gene fragment was performed based on 30 individuals of cyprinid fish with atypical phenotype, in addition to 30 S. squalus, 10 T. muticellus, and 30 R. rubilio pure individuals collected in different Italian regions, which served as reference samples. Multiple sequence alignments demonstrated that 50% of atypical-cyprinid haplotypes were maternally inherited from either S. squalus or R. rubilio. No contribution by T. muticellus was determined. Our results indicate an intergeneric hybridization event between S. squalus and R. rubilio, as a consequence of trans-introduction activities of alien species.

Evolution of persistent Anthropogenic radioactivity in Antarctic ecosystems

The primary objective of this study was to observe the evolution of anthropogenic radioactivity contamination in the Antarctic continent throughout the period 1997–1999. Moreover, results have been compared with those obtained for previous expeditions, starting from 1987. As far as 137Cs is concerned, interesting considerations could be made due to the great amount of available data. On the whole, radioactive contamination seems to be higher in continental than in marine environments. For lake algae, contamination seems to decrease gradually in the order: Tarn Flat, Edmondson Point, Carezza Lake. Focusing on 137Cs activity data, a clear temporal decreasing trend was observed in all samples: for sea water, values decreased from mean values of 0.9 Bq/m3 in 1987 to 0.5 Bq/m3 in 1999, a 56% decrease (20% of the total is due to natural decay of 137Cs). For lake waters and lake algae, the decreases are higher (80 and 30%, respectively) and the same can be assessed for sediments and soils, even if the resulting distributions are more complicated. The highest values for all radionuclides analysed were detected in terrestrial organisms (mosses, lake algae, and lichens). As a consequence, these matrices appear to be good bioindicators of radioactive contamination. Finally, although the Antarctic continent is affected by some degree by anthropogenic radioactive pollution, our results for 137Cs show that we are facing a progressive decrease. Moreover, contamination in other parts of the world is much higher: from 6–10 times in the Mediterranean Sea and 20–50 times in the North Sea and Black Sea.

Radioactive Isotopes of Strontium, Caesium and Plutonium in Sediments of the Northern Adriatic Sea

Abstract Sediment samples of different strata (0–3 and 12–15 cm) were collected between 1990 and 1992 during seasonal cruises in the Northern Adriatic Sea. A complete mapping of the Sr-90, Cs-137, Pu-238 and Pu-239(240) concentrations was obtained for samples covering a wide area, stretching from the Gulf of Trieste towards the Ancona shoreline. Sr-90 concentrations varied between 1.5 and 6.5 Bq kg−1 dw, Cs-137 was in the range 0.9–38.9 Bq kg−1 dw, Pu-239(240) in the range 0.08-1.5 Bq kg−1 dw and Pu-238 around 0.03 Bq kg−1 dw. Special reference was also put on the comparison between the off-shore environment and data obtained from samples collected inside the Po river delta. in spite of the major accumulation of Cs-137 inside the estuarine environment, higher concentrations of strontium and plutonium isotopes were detected in the offshore environment.

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

A radioecological survey in Antarctica shows that the239+240Pu,238Pu,241Am,90Sr, and137Cs activities were detectable in nearly all the samples. The activity level of239+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 of239+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.

Marine and Lacustrine Radioecological Researches in Antarctica. 1992-1994

Abstract Researches on environmental radioactivity in the Ross Sea — Terra Nova Bay area have been carried out with the aim of evaluating the role of different abiotic and biotic matrices in the cycling of radio-nuclides in the marine and lacustrine ecosystems. The transfer of Sr-90, Cs-137, Pu-238 and Pu-239(240) from the water to the benthic organisms and the sediment layer has been investigated. Contamination levels in both ecosystems and biogeochemical cycles of the main fission and transuranic products are therefore presented and discussed. A comparison of radioecological data from different areas of the Antarctic Ocean and the Mediterranean Sea is given. In the framework of the data obtained, concentrations of the natural radionuclides K-40, Th-232 and U-238 in the sediment samples, are also presented.

Evolution of Radiocontamination of the Northern and Middle Adriatic Sea in the Period 1979–1990

Abstract Several investigations were carried out on biotic and abiotic samples to determine the difference between Chernobyl and preChernobyl environmental radiocontamination of the Adriatic Sea. Special emphasis was put on the determination of 137Cs which resulted in the most abundant radionuclide in a wide variety of samples (sea water, sediment, pelagic and benthic species). Attention was also given to the neutron activation products 110mAg and 134Cs that were first discovered in the Adriatic ecosystem after the Chernobyl event in particular, although the 110Ag fallout deposition over the area was neglected in comparison to that of 137Cs, its bioaccumulation in macroalgae and molluscs was much higher suggesting some particular physiological accumulation mechanism.