RESUMO
The natural radioactivity and the associated radiation hazards of soils from the Cumanayagua Granitoide-Granitic massif in the central south of Cuba have been studied. Mass activities of the natural radionuclides 238U, 232Th and 40K varied in the ranges 10.4-33, 4.6-21.7 and 381-1201 Bq kg-1, respectively. The radium equivalent activity (91.4 ± 22.1 Bq kg-1), absorbed dose rate (45.6 ± 11.1 nGy h-1), annual effective dose rate (56.1 ± 13.7 µSv y-1) and the external hazard index (0.25 ± 0.06) have been calculated and compared with the internationally approved values. According to these results, the area can be regarded as an area with normal natural background radiation and may not pose radiological risks to the inhabitants owing to harmful effects of ionizing radiation from the natural radionuclides in soils. This study provides background radioactivity concentrations in Cumanayagua Granitoide area and generate a baseline data for radiological mapping of Cuba in the future.
Assuntos
Materiais de Construção/análise , Sedimentos Geológicos/análise , Radioisótopos de Potássio/análise , Dióxido de Silício/química , Poluentes Radioativos do Solo/análise , Solo/química , Tório/análise , Urânio/análise , Radiação de Fundo , Cuba , Humanos , Doses de Radiação , Monitoramento de RadiaçãoRESUMO
Thirteen microelements (Al, As, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Ti, V, and Zn) and four macroelements (Ca, K, Mg, and Na) were determined in the edible muscle tissue of fish in Cienfuegos Bay. Eight species, Albula vulpes, Diapterus rhombeus, Gerres cinereus, Haemulon carbonarium, Haemulon sciurus, Micropogonias furnieri, Kyphosus sectatrix, and Lutjanus cyanopterus were studied. The total concentrations and extracted concentrations using HCl were also determined in sediments. The quality of the analysis was guaranteed by validating the used analytical methods with certified reference materials of fish and sediments. The high content of macroelements confirmed the importance of fish as a valuable source of food for the local population. New information is provided on bioaccumulation of toxic elements As, Cd, Cu, Zn, and Cr in fish of the bay, with concentrations that overcame the local or international maximum allowable levels for human consumption in most samples analyzed. A high correlation between the content of toxic elements As, Cd, Zn, and macroelement K in fish and its concentration extracted from sediments using the HCl extraction method was observed.
Assuntos
Monitoramento Ambiental , Peixes/metabolismo , Oligoelementos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Baías/química , Sedimentos Geológicos/química , Músculos/metabolismoRESUMO
Sediments can be natural archives to reconstruct the history of pollutant inputs into coastal areas. This is important to improve management strategies and evaluate the success of pollution control measurements. In this work, the vertical distribution of organochlorine pesticides (DDTs, Lindane, HCB, Heptachlor, Aldrin and Mirex) was determined in a sediment core collected from the Gulf of Batabanó, Cuba, which was dated by using the (210)Pb dating method and validated with the (239,240)Pu fallout peak. Results showed significant changes in sediment accumulation during the last 40 years: recent mass accumulation rates (0.321 g cm(-2) yr(-1)) double those estimated before 1970 (0.15 g cm(-2) yr(-1)). This change matches closely land use change in the region (intense deforestation and regulation of the Colon River in the late 1970s). Among pesticides, only DDTs isomers, Lindane and HCB were detected, and ranged from 0.029 to 0.374 ng g(-1) dw for DDTs, from<0.006 to 0.05 ng g(-1) dw for Lindane and from<0.04 to 0.134 ng g(-1) dw for HCB. Heptachlor, Aldrin and Mirex were below the detection limits (â¼0.003 ng g(-1)), indicating that these compounds had a limited application in the Coloma watershed. Pesticide contamination was evident since the 1970s. DDTs and HCB records showed that management strategies, namely the banning the use of organochlorine contaminants, led to a concentration decline. However, Lindane, which was restricted in 1990, can still be found in the watershed. According to NOAA guidelines, pesticides concentrations encountered in these sediments are low and probably not having an adverse effect on sediment dwelling organisms.
Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Poluentes Químicos da Água/análise , Cuba , Oceanos e Mares , Rios/química , Água do Mar/químicaRESUMO
Analyses of faecal steroids in coastal sediments from Cienfuegos Bay Cuba indicate chronic sewage contamination at the main outfalls from the city, where concentrations of coprostanol up to 5400ngg(-)(1) (dry wt) were measured. In contrast, steroid concentrations and compositions from sites from the south part of the Bay are characteristic of uncontaminated sewage environments. The levels of coprostanol in the Cienfuegos sediments compares to the lower to mid-range of concentrations reported for coastal sediments on a world-wide basis, with sedimentary levels markedly below those previously reported for heavily impacted sites. This study delivers baseline data for further investigation of the effectiveness of the proposed sewerage plan promoted by the GEF project in Cienfuegos. Investigations on the correlations between faecal steroids and other organic contaminants confirmed that the major source of petroleum hydrocarbons within the bay was associated with the sewage effluents from the Cienfuegos city.
Assuntos
Baías/química , Colestanol/análise , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Petróleo/análise , Esgotos/química , Esteroides/análise , Cuba , Monitoramento Ambiental/estatística & dados numéricos , Fezes/química , Hidrocarbonetos/análiseRESUMO
The radioactivity of NORM was measured in ashes collected from a fuel-oil power plant in Cienfuegos, Cuba, using an HPGe gamma-ray spectrometer. The (226)Ra, (210)Pb, (40)K, (232)Th and (238)U activity concentrations reached 240, 77, 59, 70 and 15 Bq kg(-1), respectively. The potential radiological hazard of these residuals was assessed. The radium equivalent activities of the samples varied from 54 to 345 Bq kg(-1). The gamma index was calculated to be lower than that of the reference values, and the gamma absorbed dose rate was higher than the average reported for the earth's crust; however, the assessed annual effective dose was slightly lower than the annual effective dose limit for public, i.e. 1 mSv. Therefore, these bottom ashes were not dramatically enriched with radionuclides and may be used as an additive for building materials without restrictions from a radiological protection point of view.
Assuntos
Óleos Combustíveis , Monitoramento de Radiação/métodos , Radioisótopos/análise , Poluentes Radioativos do Solo/análise , Espectrometria gama/métodos , Absorção , Cuba , Geografia , Radioisótopos de Chumbo/análise , Radioisótopos de Potássio/análise , Centrais Elétricas , Rádio (Elemento)/análise , Tório/análise , Urânio/análiseRESUMO
The spatial distribution of various organochlorinated compounds, e.g. PCBs, DDTs, HCB and HCHs, were investigated in sediments of the Gulf of Batabanó, Cuba. Among the target organochlorine compounds measured, ΣDDT isomers were the predominant contaminant with concentrations ranging from 0.019 to 1.27 ng g(-1)dry wt. Lindane was present at very low concentrations in the range n.d. to 0.05 ng g(-1), while PCBs and other organochlorine pesticide residues, such as HCB, Heptaclor, Aldrin and Mirex were lower than detection limits (â¼0.010 ng g(-1)). According to established sediment quality guidelines, the OCPs concentrations encountered in the surface sediments are probably not having an adverse effect on sediment dwelling organisms. Compared to concentrations reported in coastal environments from other parts of the world, PCBs and OCs concentrations in surface sediments of Batabanó Gulf were low and similar to the reported for remote and pristine environments. These results contribute to the sparse regional database for organochlorinated compounds in the Caribbean marine environment.
Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/química , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Cuba , Água do Mar/químicaRESUMO
The vertical activity distribution and inventories of (239+240)Pu profile and Hg were determined in Sagua la Grande estuary, Cuba. The shape of the (239+240)Pu profile in the core column resembled very closely the history of atmospheric nuclear weapons' testing, and the maximum deposition in 1963 was recorded in the sediment core history. The (239+240)Pu activity concentrations in the surface layer sediments varied from 0.163 to 0.611 mBq g(-1). The inventory of (239+240)Pu was 42 ± 5.6 Bq m(-2), a value close to that expected from direct global fallout. Using the (239+240)Pu as a chronomarker the mass sedimentation rate in the area for the last 60 years was calculated, reaching values of 0.173 g cm(-2) y(-1). The mercury profile reflects the history of anthropogenic pollution in the estuary and perfectly describes the operation of the mercury-cell chlor-alkali plant, for production of NaOH, which began operations in 1980. The inventory of Hg was 2.42 ± 0.19 µg cm(-2). These results contribute to the scarce regional database for pollutants and anthropogenic radionuclides in the Caribbean marine environment, particularly in relation to (239+240)Pu.
Assuntos
Sedimentos Geológicos/química , Mercúrio/análise , Plutônio/análise , Poluentes Químicos da Água/análise , Poluentes Radioativos da Água/análise , Cuba , Monitoramento de RadiaçãoRESUMO
Total mercury levels were quantified in sediments and oyster tissues (Crassostrea rizophorae) from the Sagua la Grande River estuary and offshore mangrove keys 19 km downstream of a chlor-alkali plant (CAP) in Villa Clara, Cuba. Relatively elevated total mercury levels were found in sediments from the estuary itself, ranging from 0.507 to 1.81 µg g(-1) dry weight. However, levels were lower in sediments from the keys farther from the estuary. Oyster mercury levels were always acceptable for human consumption, although levels significantly correlated in sediments and oysters across sampling sites (p < 0.05), which suggests that mercury from the CAP is impacting coastal water quality conditions.
Assuntos
Crassostrea/metabolismo , Sedimentos Geológicos/química , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Cuba , Monitoramento Ambiental , Água Doce/química , Mercúrio/análise , Rhizophoraceae , Água do Mar/química , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricosRESUMO
Since 1998 the highly polluted Havana Bay ecosystem has been the subject of a mitigation program. In order to determine whether pollution-reduction strategies were effective, we have evaluated the historical trends of pollution recorded in sediments of the Bay. A sediment core was dated radiometrically using natural and artificial fallout radionuclides. An irregularity in the (210)Pb record was caused by an episode of accelerated sedimentation. This episode was dated to occur in 1982, a year coincident with the heaviest rains reported in Havana over the XX century. Peaks of mass accumulation rates (MAR) were associated with hurricanes and intensive rains. In the past 60 years, these maxima are related to strong El Niño periods, which are known to increase rainfall in the north Caribbean region. We observed a steady increase of pollution (mainly Pb, Zn, Sn, and Hg) since the beginning of the century to the mid 90 s, with enrichment factors as high as 6. MAR and pollution decreased rapidly after the mid 90 s, although some trace metal levels remain high. This reduction was due to the integrated coastal zone management program introduced in the late 90 s, which dismissed catchment erosion and pollution.
Assuntos
Ecossistema , Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/análise , Cuba , Radioisótopos de Chumbo/análise , Fatores de Tempo , Poluição Química da Água/prevenção & controleRESUMO
The spatial distribution of various organochlorinated compounds, e.g. PCBs, DDTs, HCB and HCHs, were investigated in sediments from Cienfuegos bay, Cuba. Their concentrations appeared to be relatively low by global standards and only sediments receiving the impact from the residual waters of the city and thermoelectrical power approached the sediment quality guidelines for PCBs and DDTs. Relatively higher SigmaDDT concentrations and high DDT/DDE+DDD ratios in two sites near the outfalls of the city indicated a current DDT usage, probably linked to public health emergencies. These results contribute to the sparse regional database for organochlorinated compounds in the Caribbean marine environment.
Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/análise , Hidrocarbonetos Clorados/análise , Poluentes Químicos da Água/análise , Oceano Atlântico , CubaRESUMO
The spatial distribution of aliphatic and polycyclic aromatic hydrocarbons (PAHs) was investigated in sediments from the Cienfuegos bay. The highest anthropogenic hydrocarbon inputs were found near the city of Cienfuegos with an unresolved complex mixture (UCM) of aliphatic hydrocarbons and alkylated PAHs, indicative of petrogenic inputs. Parent PAHs, which are typical of high-temperature combustion processes, were evenly distributed in the whole basin and largely prevailing in the southern part of the Cienfuegos city. Biomarker fingerprints assign the sources of pollution to mixes of national and non-national crude oils. The overall levels of anthropogenic hydrocarbons are relatively high compared to relevant areas worldwide and reveal a moderate/high level of hydrocarbon pollution. The Cienfuegos bay sediments received over a period of 5 yr, 50 T/yr of petrogenic unresolved hydrocarbons (UCM) and 2 T/yr of PAHs, being deposited the 80% in the sediments of the north basin.
Assuntos
Sedimentos Geológicos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Oceano Atlântico , Cuba , Monitoramento Ambiental , GeografiaRESUMO
The vertical distribution of Hg and Pb were determined in a sediment core collected from the Sagua estuary (North Cuba) that receives input from the Sagua river, one of the most polluted rivers discharging into the Cuban coastal environment. Depth profiles of metal concentrations were converted to time-based profiles using the (210)Pb dating method and confirmed with the (137)Cs fallout peak. The mean mass accumulation rate was estimated to be 0.17+/-0.04 g cm(-2)y(-1) (mean sediment accumulation rate 0.52+/-0.13 cm y(-1)) and the core bottom was estimated to date back about 130 years. The historical sedimentary record showed a strong enrichment of mercury concentrations in the past decades, caused by the incomplete treatment of industrial wastes from a chlor-alkali plant with mercury-cell technology in the Sagua river basin. Lead fluxes to sediments showed a gradual increase from the 1920s to present, which agrees with a population increase in Sagua la Grande City. Fluxes of both metals have increased the past 25 years, with values reaching a maximum of 0.5 and 3.9 microg cm(-2)y(-1) for Hg and Pb, respectively.
Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/química , Chumbo/análise , Mercúrio/análise , Poluentes Químicos da Água/análise , Radioisótopos de Césio/análise , Cuba , Radioisótopos de Chumbo/análise , Água do Mar , Fatores de TempoRESUMO
Levels of 137Cs in total atmospheric deposition have been measured in the Cienfuegos region (Cuba) between 1994 and 2002. Samples were collected every three months, evaporated to dryness to obtain residual samples, and measured by gamma spectrometry. The 137Cs mean concentration in total deposition was 0.24 Bq m(-2) and data ranged between < 0.05 and 0.62 Bq m(-2). Precipitation rates and raintime have proved to be the most important factors controlling the concentration and depositional flux of 137Cs in the atmosphere over Cienfuegos, showing a high correlation coefficient (R = 0.93).
Assuntos
Poluentes Radioativos do Ar/análise , Radioisótopos de Césio/análise , Atmosfera , Precipitação Química , Cuba , ChuvaRESUMO
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.