RESUMO
This paper presents the levels and distribution of 210Po in different compartments of a coastal lagoon on the east coast of Uruguay (South America). Activity concentrations of 210Po have been obtained in different matrices, such as water, superficial sediments, clams (Diplodon sp.), freshwaters snails (Pomacea sp.), zooplankton, and fishes (Jenynsia sp.), collected at different points of the lagoon and during several sampling campaigns. In addition, the organic matter content of the sediment was determined to study the variation of 210Po along the lagoon. The activity concentrations of 210Po in the water samples are in the range between 1.1 ± 0.2-3.5 ± 0.4 mBq/L while in the sediment samples vary between 17.1 ± 1.4 and 540 ± 12 Bq/kg, DW. In the case of biota, the ranges obtained were 182 ± 5-265 ± 6 Bq/kg, DW in clams and 134 ± 4-1245 ± 16 Bq/kg, DW in snail samples. A good correlation of 210Po with the organic fractions of the sediment was observed (r = 0.8798, p-value < 0.001), being obtained high values for the distribution coefficient Kd (104 -105). In the biota samples, a clear difference was observed in the 210Po concentration values in both species, mainly due to the different feeding habits of both aquatic organisms, as it is reflected in the associated concentration ratios (CR). In this paper, a good set of results of 210Po, Kd, and CR have been obtained in different matrices, enhancing the limited archives available for modelers concerning these parameters for 210Po and freshwater systems.
Assuntos
Polônio , Monitoramento de Radiação , Animais , Monitoramento Ambiental , Sedimentos Geológicos , Polônio/análise , UruguaiRESUMO
The accumulation of detectable amounts of radon progeny in human tissues may be a risk factor for development and progression of chronic diseases. In this preliminary study, we analyzed the levels of alpha-emitting radon progeny Polonium-210 (210Po) in the olfactory epithelium, olfactory bulb, frontal lobe, and lung tissues in cadavers from the city of Sao Paulo, SP, Brazil. We also assessed the association between 210Po levels and exposure parameters for urban air pollution using linear regression models adjusted for age, sex, smoke, time living in Sao Paulo, daily commuting, socioeconomic index, and anthracosis (traffic-related black carbon accumulation in the pleural region and in lymph). Our findings show that the concentration of 210Po was associated with anthracosis in lungs of non-smokers (coefficient = 6.0; standard error = 2.9; p = 0.04). Individuals with lower socioeconomic status also had significantly higher 210Po levels in lungs (coefficient = -1.19; standard error = 0.58; p = 0.042). The olfactory bulb had higher 210Po levels than either olfactory epithelium (p = 0.071), frontal lobe (p < 0.001), or lungs (p = 0.037). Our findings of the deposition of 210Po in autopsy tissues suggest that airborne radionuclides may contribute to the development of chronic diseases, including neurodegenerative diseases.
Assuntos
Poluentes Radioativos do Ar/análise , Encéfalo/metabolismo , Pulmão/metabolismo , Polônio/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Autopsia , Brasil , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto JovemRESUMO
The activity concentrations of alpha-emitters comprising isotopes of uranium (238, 234, 235U) and polonium (210Po) were measured using alpha-particle spectrometry in natural spring waters in the province of Granada, Spain. These water are consumed by the population of the zone who live in villages. This is almost half of the population of the whole region. Mean values of activity concentrations found are 42.61 ± 2.66; 49.55 ± 3.03; 1.64 ± 0.28 and 1.74 ± 0.15 mBq L-1 for 238U, 234U, 235U and 210Po, respectively. Finally, the radiological impact of the analysed waters has been determined, in terms of the estimation of the committed annual effective dose due to the ingestion of the water. The assessment has been carried out for five age groups with the aim to cover all the population. The calculated annual effective doses are observed to be below the prescribed dose limit of 100 µSv y-1 recommended by WHO.
Assuntos
Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Nascentes Naturais , Polônio/análise , Doses de Radiação , Monitoramento de Radiação/métodos , Urânio/análise , Poluentes Radioativos da Água/análise , Humanos , Espanha , Abastecimento de ÁguaRESUMO
210Po and 210Pb activity concentrations in spas groundwaters occurring at São Paulo (SP) and Minas Gerais (MG) states, Brazil, have been reported in this paper with a dual purpose: to compare different indices for evaluating the radionuclides mobility into waters and to evaluate the drinking water quality from dose calculations. The waters (75 sampling points) are extensively used for drinking in public places, bottling and bathing purposes, among other. The samples were taken from springs and wells drilled at different aquifer systems inserted in Paraná and Southeastern Shield hydrogeological provinces. The WHO guideline reference value for 210Pb and 210Po of 0.1 Bq/L in drinking water was not reached for 210Pb but the 210Po levels were equal or above it in four spas groundwaters from MG State. The maximum WHO guidance dose level of 0.1 mSv/yr was also reached or surpassed in them. The 210Pb "mobility index" taking into account the ratio of the weight of the dissolved 210Pb per unit volume of solution to its weight per unit weight of the rock matrix yielded values in the range of 0.01-5.2 kg/m3. Another "mobility index" (Preference Ratio) expressing the ratio of 210Pb and 238U in the waters divided by the ratio of 210Pb and 238U in the rock matrices provided values between 0.004 and 7994. The 210Pb/238U activity ratios of some spas groundwaters suggested preferential 238U transport relative to 210Pb into the liquid phase, whereas the ratio of the 210Pb to 238U mobility indices indicated the opposite. Such finding showed a better usefulness of the mobility indices for evaluating processes affecting the radionuclides release into the liquid phase during the water/rock interactions.
Assuntos
Água Subterrânea/química , Fontes Termais/química , Radioisótopos de Chumbo/análise , Polônio/análise , Monitoramento de Radiação , Poluentes Radioativos da Água/análise , Brasil , Abastecimento de ÁguaRESUMO
With less than 60 records being reported worldwide, the megamouth (Megachasma pelagios) is today one of the least known shark species inhabiting our oceans. Therefore, information concerning the biology and ecology of this enigmatic organism is very scarce and limited to feeding behaviour and preferred habitat. The present work reports new data on the concentrations of trace elements, organic mercury, POPs and (210)Po in hepatic and muscular tissues of a specimen found stranded in the southeastern coast of Brazil. Additionally, we provide new evidence based on stable isotope analysis (δ(15)N and δ(13)C) confirming the preference for the pelagic habitat and the zooplanktivorous feeding behaviour of the megamouth. These results are consistent with the low concentrations of organic pollutant compounds and other elements measured in our samples.
Assuntos
Polônio/análise , Tubarões/fisiologia , Poluentes Químicos da Água/análise , Animais , Brasil , Isótopos de Carbono/análise , Ecossistema , Comportamento Alimentar , Mercúrio/análise , Isótopos de Nitrogênio/análise , Compostos Orgânicos/análise , Tubarões/genética , Oligoelementos/análise , Poluentes Químicos da Água/farmacocinéticaRESUMO
In this study, we report the (210)Po and (210)Pb concentrations of bone, muscle and liver samples that were obtained from twelve different marine bird species stranded on beaches in the central-north region of Rio de Janeiro State. Both radionuclides were highly concentrated in the liver samples; however, the lowest mean (210)Po/(210)Pb activity ratio (1.3) was observed in bones compared with liver and muscle (16.8 and 13.8, respectively). Among the species that were studied, Fregata magnificens, with a diet based exclusively on fish, had the lowest (210)Pb and (210)Po concentrations and the lowest (210)Po/(210)Pb activity ratio. The (210)Po concentrations in Puffinus spp. liver samples followed a log-normal distribution, with a geometric mean of 300 Bq kg(-1)wet weight. Only two references pertaining to (210)Po in marine birds were found in a Web of Science search of the literature, and each study reported a different concentration value. The values determined in this experiment are consistent with those in one of the previous studies, which also included one of the species studied in this work. No values for (210)Pb in marine birds have been published previously.
Assuntos
Aves , Radioisótopos de Chumbo/metabolismo , Polônio/metabolismo , Monitoramento de Radiação , Animais , Osso e Ossos/metabolismo , Brasil , Fígado/metabolismo , Músculos/metabolismoRESUMO
Polonium-210 ((210)Po) concentration was quantified in the muscle tissue and organs of two predatory marine fishes (Genypterus brasiliensis and Cynoscion microlepidotus) from Cabo Frio, Rio de Janeiro, Brazil. The species C. microlepidotus, a benthic carnivore, registered higher (210)Po in its tissue. The organs associated with digestion displayed the maximum radionuclide compared with other organs. The average activity was 2 mBq kg(-1) for G. brasiliensis and it was 6 mBq kg(-1) for C. microlepidotus. The activity concentrations varied significantly between the species and among organs.
Assuntos
Exposição Ambiental , Peixes/metabolismo , Polônio/metabolismo , Poluentes Radioativos da Água/metabolismo , Animais , Brasil , Monitoramento de Radiação , Especificidade da EspécieRESUMO
Monthly sampling in northwestern Mediterranean coastal waters was undertaken to better understand the relationship between zooplankton biomass and the cycling of the natural radionuclide (210)Po/(210)Pb pair during a one-year period (October 1995-November 1996). In conjunction with mesozooplankton collections and (210)Po/(210)Pb measurements in seawater, zooplankton and their fecal pellets, the biochemical composition of particulate organic matter (POM) was also examined at three depths (0, 20 and 50 m) as an indicator of trophic conditions. During May 1996, a strong zooplankton "bloom" was observed which was preceded by a prolonged increase in POM (protein + carbohydrates + lipids) starting at the end of March, and further demonstrated by a concomitant increase in the concentration of smaller particles, two features that are typical of mesotrophic waters. Simultaneous measurements of (210)Po in sea water and zooplankton showed an inverse trend between these two parameters during the sampling period, with the two lowest (210)Po concentrations in the dissolved phase of seawater coincident with the highest radionuclide concentrations in the zooplankton; however, this apparent relationship was not statistically significant over the entire year. Freshly excreted mesozooplankton and salp fecal pellets, which have been strongly implicated in the removal and downward transport of these radionuclides from the upper water column, contained (210)Po and (210)Pb levels ranging from 175 to 878 and 7.5-486 Bq kg(-1) dry weight, respectively. Salp pellets contained 5 and 10 times more (210)Po and (210)Pb than in fecal pellets produced by mixed zooplankton, a finding most likely related to their different feeding strategies. During the zooplankton biomass peak observed in May, the (210)Po concentration in zooplankton was at a minimum; however, in contrast to what has been reported to occur in some open sea oligotrophic waters, over the year no statistically significant inverse relationship was found between zooplankton biomass and (210)Po concentration in zooplankton. This observation may have resulted from the general lack of very low biomass concentrations (<1 mg m(-3)) measured in these coastal waters, biomass levels which commonly occur in open ocean oligotrophic regions.
Assuntos
Radioisótopos de Chumbo/análise , Polônio/análise , Poluentes Radioativos da Água/análise , Zooplâncton/química , Animais , Biomassa , Mar Mediterrâneo , Monitoramento de RadiaçãoRESUMO
Daily mineral intake (DMI) of Cu and Zn, percentage weekly intake (PWI) of As, Cd, Hg, Pb, and doses of (210)Po were estimated by using their elemental concentration in muscle of two tuna species and the average tuna consumption in Mexico. Skipjack tuna Katsuwonus pelamis had significantly (p < 0.05) higher levels of As (1.38 µg g(-1) dw) and Cu (1.85 µg g(-1) dw) than yellowfin tuna Thunnus albacares, whereas Pb concentrations (0.18 µg g(-1) dw) were significantly (p < 0.05) higher in T. albacares. The sequence of elemental concentrations in both species was Zn > Cu > As > Hg > Pb > Cd. In T. albacares, concentrations of Cd and Pb in muscle tissue were positively correlated (p < 0.05) with weight of specimens, while Cu was negatively correlated. DMI values were below 10 %. PWI figures (<2 %) are not potentially harmful to human health. (210)Po concentration in T. albacares and K. pelamis accounts for 13.5 to 89.7 % of the median individual annual dose (7.1 µSv) from consumption of marine fish and shellfish for the world population.
Assuntos
Músculos/metabolismo , Perciformes/metabolismo , Polônio/metabolismo , Oligoelementos/metabolismo , Atum/metabolismo , Animais , Arsênio/metabolismo , Cádmio/metabolismo , Cobre/metabolismo , Chumbo/metabolismo , Mercúrio/metabolismo , Oceano Pacífico , Zinco/metabolismoRESUMO
The (210)Po concentration of muscle and liver samples obtained from dolphins stranded on beaches in the Southeastern region of Rio de Janeiro State was analyzed in the present study. The samples were primarily obtained from "Franciscana" (Pontoporia blainvillei) and "Guiana" dolphins (Sotalia guianensis); however, samples from four other species were also evaluated. The (210)Po concentration of muscle samples obtained from "Franciscana" dolphins (66.7±6.7, n=8)Bq kg(-1)w.w. was greater than that of "Guiana" dolphins (25.3±5.7, n=8)Bq kg(-1)w.w. due to differences in the diets of these species. Alternatively, the (210)Po concentrations of liver samples obtained from different species were statically equivalent. Compared to the results described in the literature, the muscle samples evaluated in the present study displayed lower (210)Po concentrations, except for those obtained from "Franciscana" dolphins, which exhibited similar values. For "Franciscana" and "Guiana" dolphins, a clear relationship between the (210)Po concentration of muscle and liver samples and the size of the dolphin was not observed.
Assuntos
Golfinhos , Polônio/análise , Poluentes Radioativos da Água/análise , Animais , Brasil , Fígado/química , Músculos/química , Doses de Radiação , Monitoramento de RadiaçãoRESUMO
This paper describes the natural radioactivity of groundwater occurring in sedimentary (Bauru and Guarani) and fractured rock (Serra Geral) aquifer systems in the Paraná sedimentary basin, South America that is extensively used for drinking purposes, among others. The measurements of gross alpha and gross beta radioactivity as well the activity concentration of the natural dissolved radionuclides 4°K, ²³8U, ²³4U, ²²6Ra, ²²²Rn, ²¹°Po and ²¹°Pb were held in 80 tubular wells drilled in 21 municipalities located at São Paulo State and its border with Mato Grosso do Sul State in Brazil. Most of the gross alpha radioactivity data were below 1 mBq/L, whereas values exceeding the gross beta radioactivity detection limit of 30 mBq/L were found. The radioelement solubility in the studied systems varied according to the sequence radon>radium>other radionuclides and the higher porosity of sandstones relatively to basalts and diabases could justify the enhanced presence of dissolved radon in the porous aquifer. The implications of the data obtained in terms of standards established for defining the drinking water quality have also been discussed. The population-weighted average activity concentration for these radionuclides was compared to the guideline value of 0.1 mSv/yr for the total effective dose and discussed in terms of the choice of the dose conversion factors.
Assuntos
Água Subterrânea/química , Radioisótopos/análise , Poluentes Radioativos da Água/análise , Partículas beta , Brasil , Radioisótopos de Chumbo/análise , Polônio/análise , Radioisótopos de Potássio/análise , Monitoramento de Radiação , Rádio (Elemento)/análise , Radônio/análise , Urânio/análiseRESUMO
Polonium-210 ((210)Po) radioactive concentrations were determined in human semen fluid of vasectomized non-smoker volunteers. The (210)Po levels ranged from 0.10 to 0.39 mBq g(-1) (mean: 0.23 ± 0.08 mBq g(-1)). This value decreased to 0.10 ± 0.02 mBq g(-1) (range from 0.07 to 0.13 mBq g(-1)) after two weeks of a controlled diet, excluding fish and seafood. Then, volunteers ate during a single meal 200 g of the cooked mussel Perna perna L., and (210)Po levels were determined again, during ten days, in semen fluid samples collected every morning. Volunteers continued with the controlled diet and maintained sexual abstinence through the period of the experiment. A 300% increase of (210)Po level was observed the day following mussel consumption, with a later reduction, such that the level returned to near baseline by day 4.
Assuntos
Bivalves/efeitos dos fármacos , Contaminação Radioativa de Alimentos/análise , Polônio/toxicidade , Monitoramento de Radiação , Alimentos Marinhos/toxicidade , Sêmen/química , Sêmen/efeitos dos fármacos , Adulto , Animais , Bivalves/química , Bivalves/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Polônio/análise , Polônio/metabolismo , Medição de Risco , Sêmen/metabolismoRESUMO
Madame Curie foi a primeira mulher a atuar como docente na Sorbonne, primeira a receber não apenas um, mas dois prêmios Nobel. Primeira cientista laureada pelo Nobel a ter filha também laureada. Descobriu dois novos elementos radioativos, o Polônio e o Rádio. Atuou na Primeira Guerra Mundial fazendo radiografia de soldados feridos. Em agosto de 1926, esteve em Belo Horizonte em visita ao Instituto do Radium, hoje Hospital Borges da Costa, e proferiu palestra na Faculdade de Medicina. (AU)
Assuntos
História da Medicina , Pesquisadores/história , Biografias como Assunto , Radiologia/história , Polônio , Rádio (Elemento) , Brasil , PolôniaRESUMO
Measurement of 222Rn is an important research concern because of the high-energy alpha emission of its 218Po and 214Po progeny. The LR-115 passive detector is the basis of a solid-state nuclear track detector (SSNTD) whose use for radon measurements has been well established. The usage of the SSNTD technique requires calibration by comparison. The aim of this work is to evaluate the efficiency calibration parameters for the radon measurement system that three steps: (1) irradiation conditions, (2) etching conditions, and (3) track counting. The following parameters were evaluated: breakdown and counting voltages for the spark counter, detector thickness, etching time, temperature and NaOH concentration as etching conditions for the LR-115 detector. Calibrating factors of 0.035 and 0.028 tracks cm-2 Bq-1 m3 d-1 for the open- and closed-chamber radon monitors, respectively, were determined considering the best efficiency calibration parameter values.
Assuntos
Poluentes Radioativos do Ar/análise , Monitoramento de Radiação/instrumentação , Radiometria/instrumentação , Radônio/análise , Partículas alfa , Calibragem , Polônio/análise , Hidróxido de Sódio/química , Fatores de TempoRESUMO
Twenty ropes with 400 Perna perna mussels seeds (3 cm shell size) were set-up on floating structures at Cabo Frio Island, Arraial do Cabo, approximately 100 km northeast of Rio de Janeiro city. A rope was taken out on a monthly basis, and the shell sizes of 100 seeds were measured. The haemolymph of 10 male and 10 female individuals was taken, and the same individuals were separated for 210Po/210Pb determination. After one year of monthly sampling, no clear correlation was observed between the 210Po concentration, mussel's age and weight. A mean 210Po concentration of 155 Bq kg(-1) wet weight basis, was obtained, which is comparable with data reported in the literature. The radiation dose did not have any observable effect on the micronuclei frequency and DNA breaks in the mussels. This was probably due to the low dose rate, 0.02 mGy d(-1), in comparison with the suggested potential dose limit of 10 mGy d(-1).
Assuntos
Bivalves/metabolismo , Polônio/análise , Animais , Biomarcadores , Bivalves/efeitos da radiação , Brasil , Ensaio Cometa , Dano ao DNA , Monitoramento Ambiental/métodos , Feminino , Hemolinfa/metabolismo , Masculino , Testes para Micronúcleos , Monitoramento de Radiação/métodos , Poluentes Químicos da Água , Poluentes Radioativos da ÁguaRESUMO
Marie Curie y su esposo Pierre, fueron los descubridores de la radioactividad, junto a los elementos polonio y radio. Marie dedicó más de treinta y cinco años de su carrera científica al estudio de esta entidad. Con tenacidad y esfuerzo logró destacarse en una época donde el machismo y la xenofobia estaban presentes en todas partes. Por sus méritos, fue la primera persona en recibir dos premios Nobel: el de Física en 1903 y el de Química en 1911. Para los autores de esta publicación es un orgullo traer nuevamente a la luz la vida y obra de esta extraordinaria mujer.
Assuntos
Humanos , Pesquisadores/história , Radioatividade , Radiologia/história , Prêmio Nobel , Polônio/história , Rádio (Elemento)/históriaRESUMO
Cigarette smoking is one of the pathways that might contribute significantly to the increase in the radiation dose reaching man, due to the relatively large concentrations of 210Pb and 210Po found in tobacco leaves. In the present study, the concentrations of these two radionuclides were determined in eight of the most frequently sold cigarette brands produced in Brazil. 210Pb was determined by counting the beta activity of 210Bi with a gas flow proportional detector after radiochemical separation and precipitation of PbCrO4. 210Po was determined by alpha spectrometry using a surface barrier detector after radiochemical separation and spontaneous deposition of Po on a copper disk. The results showed concentrations ranging from 11.9 to 30.2 mBq per gram of dry tobacco for 210Pb and from 10.9 to 27.4 mBq per gram of dry tobacco for 210Po. The collective committed effective dose resulting from the use of cigarettes produced in Brazil per year is estimated to be 1.5 x 10(4) man-Sv.
Assuntos
Radioisótopos de Chumbo/análise , Polônio/análise , Fumar , Poluição por Fumaça de Tabaco/análise , Brasil , Humanos , Manufaturas , NicotianaRESUMO
One part of Radiological Monitoring Programme in central Cuba (1991-1995) was dedicated to study the background levels of natural and anthropogenic radioactivity in Cienfuegos Bay in the vicinity of the first Cuban nuclear power station under construction. 210Po and 137Cs concentrations in fish, molluscs and crustaceans collected in Cienfuegos Bay were determined and the committed effective doses (CED) were calculated for two population groups inhabiting this region. The highest values of 210Po concentrations were found in crustaceans, but significant accumulation was also observed in fish and molluscs. The mean 137Cs concentrations in organisms are several times lower with respect to 210Po, a situation that characterises the regions affected by the global fallout only. Values of CED from the consumption of crustaceans and molluscs are very low both from 210Po and 137Cs. The mean individual dose from 210Po in the seafood consumed varies from 39 microSv for general populations to 2802 microSv for the "critical group" consuming 320 kg of fish per year. The dose from 137Cs is negligible.
Assuntos
Contaminação de Alimentos , Cinza Radioativa/análise , Alimentos Marinhos , Animais , Radioisótopos de Césio/análise , Radioisótopos de Césio/farmacocinética , Crustáceos , Cuba , Monitoramento Ambiental , Peixes , Humanos , Moluscos , Polônio/análise , Polônio/farmacocinéticaRESUMO
The fluminense vegetation, more specifically the flora from the Jurubatiba restinga has been investigated by a multidisciplinary team of botanists, chemist, radiobiologist, insect physiologists and geneticist. Vouchers of 564 specimens have been collected, identified, organized in an herbarium, and a database is being build up containing, in addition to classical botanical data, chemical data and information on the potential economic use either for landscape gardening, alternative foods or as medicinal plants. Phytochemical studies of the Guttiferae, Clusia hilariana, yielded oleanolic acid and nemorosone. Their biological activities against the haematophagous insect Rhodnius prolixus vector of Chagas disease have been investigated. Finally, it has been observed that aquatic plants possessed high levels of the natural radionuclide polonium-210, which seems to be originated mainly from soil rather than from atmospheric supply.
Assuntos
Benzofenonas/farmacologia , Plantas , Animais , Brasil , Água Doce/química , Insetos Vetores/efeitos dos fármacos , Ácido Oleanólico/farmacologia , Plantas/química , Plantas/classificação , Plantas/toxicidade , Plantas Comestíveis , Plantas Medicinais , Polônio/análise , Rhodnius/efeitos dos fármacosRESUMO
The fluminense vegetation, more specifically the flora from the Jurubatiba restinga has been investigated by a multidisciplinary team of botanists, chemist, radiobiologist, insect physiologists and geneticist. Vouchers of 564 specimens have been collected, identified, organized in an herbarium, and a database is being build up containing, in addition to classical botanical data, chemical data and information on the potential economic use either for landscape gardening, alternative foods or as medicinal plants. Phytochemical studies of the Guttiferae, Clusia hilariana, yielded oleanolic acid and nemorosone. Their biological activities against the haematophagous insect Rhodnius prolixus vector of Chagas disease have been investigated. Finally, it has been observed that aquatic plants possessed high levels of the natural radionuclide polonium-210, which seems to be originated mainly from soil rather than from atmospheric supply