RESUMO
Even relatively low levels of metals exposure may impact health, particularly among vulnerable populations such as infants and young children. However, little is known about the interplay between simultaneous metal exposures, common in real-life scenarios, and their association with specific dietary patterns. In this study, we have evaluated the association between adherence to Mediterranean diet (MD) and urinary metal concentrations individually and as an exposure mixture in 713 children aged 4-5-years from the INMA cohort study. We used a validated food frequency questionnaire to calculate two MD indexes scores: aMED and rMED. These indexes gather information on various food groups within the MD and score differently. To measure urinary concentrations of cobalt, copper, zinc, molybdenum, selenium, lead, and cadmium as exposure biomarkers, we used inductively coupled plasma mass spectrometry (ICP-MS), coupled with an ion chromatography (IC) equipment for arsenic speciation analysis. We applied linear regression and quantile g-computation, adjusted for confounders, to analyse the association between MD adherence and exposure to the metal mixture. High adherence to MD such as the quintile (Q) 5 MD was associated with higher urinary arsenobetaine (AsB) levels than Q1, with ß values of 0.55 (confidence interval - CI 95% 0.01; 1.09) for aMED and 0.73 (CI 95% 0.13; 1.33) for rMED. Consumption of fish was associated with increased urinary AsB but reduced inorganic arsenic concentrations. In contrast, the aMED vegetables consumption increased urinary inorganic arsenic content. A moderate level of adherence to MD (Q2 and Q3) was associated with lower copper urinary concentrations than Q1, with ß values of -0.42 (CI 95% -0.72; -0.11) for Q2 and -0.33 (CI 95% -0.63; -0.02) for Q3, but only with aMED. Our study, conducted in Spain, revealed that adhering to the MD reduces exposure to certain metals while increasing exposure to others. Specifically, we observed increase in exposure to non-toxic AsB, highlighting the significance of consuming fish/seafood. However, it is crucial to emphasize the necessity for additional efforts in reducing early-life exposure to toxic metals, even when adhering to certain food components of the MD.
Assuntos
Arsênio , Dieta Mediterrânea , Animais , Arsênio/urina , Cobre , Estudos de Coortes , Espanha , MetaisRESUMO
Considerable ambiguity remains over the extent and nature of millennial/centennial-scale climate instability during the Last Interglacial (LIG). Here we analyse marine and terrestrial proxies from a deep-sea sediment sequence on the Portuguese Margin and combine results with an intensively dated Italian speleothem record and climate-model experiments. The strongest expression of climate variability occurred during the transitions into and out of the LIG. Our records also document a series of multi-centennial intra-interglacial arid events in southern Europe, coherent with cold water-mass expansions in the North Atlantic. The spatial and temporal fingerprints of these changes indicate a reorganization of ocean surface circulation, consistent with low-intensity disruptions of the Atlantic meridional overturning circulation (AMOC). The amplitude of this LIG variability is greater than that observed in Holocene records. Episodic Greenland ice melt and runoff as a result of excess warmth may have contributed to AMOC weakening and increased climate instability throughout the LIG.
RESUMO
Schools represent a critical microenvironment in terms of air quality due to the proximity to outdoor particle sources and the frequent lack of proper ventilation and filtering systems. Moreover, the population exposed in schools (i.e. children) represents a susceptible population due to their age. Air quality-based studies involving students' exposure at schools are still scarce and often limited to mass-based particle metrics and may thus underestimate the possible effect of sub-micron particles and particle toxicity. To this purpose, the present paper aims to evaluate the exposure to different airborne particle metrics (including both sub- and super-micron particles) and attached carcinogenic compounds. Measurements in terms of particle number, lung-deposited surface area, and PM fraction concentrations were measured inside and outside schools in Barcelona (Spain) and Cassino (Italy). Simultaneously, PM samples were collected and chemically analysed to obtain mass fractions of carcinogenic compounds. School time airborne particle doses received by students in classrooms were evaluated as well as their excess lung cancer risk due to a five-year primary school period. Median surface area dose received by students during school time in Barcelona and Cassino resulted equal to 110mm2 and 303mm2, respectively. The risk related to the five-year primary school period was estimated as about 2.9×10-5 and 1.4×10-4 for students of Barcelona and Cassino, respectively. The risk in Barcelona is slightly higher with respect to the maximum tolerable value (10-5, according to the U.S. Environmental Protection Agency), mainly due to toxic compounds on particles generated from anthropogenic emissions (mainly industry). On the other hand, the excess lung cancer risk in Cassino is cause of concern, being one order of magnitude higher than the above-mentioned threshold value due to the presence of biomass burning heating systems and winter thermal inversion that cause larger doses and great amount of toxic compounds on particles.
Assuntos
Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Neoplasias Pulmonares/epidemiologia , Material Particulado/análise , Poluentes Atmosféricos/análise , Poluição do Ar , Criança , Europa (Continente) , Humanos , Itália/epidemiologia , Instituições Acadêmicas , Espanha/epidemiologiaRESUMO
Source contributions of organic aerosol (OA) are still not fully understood, especially in terms of quantitative distinction between secondary OA formed from anthropogenic precursors vs. that formed from natural precursors. In order to investigate the OA origin, a field campaign was carried out in Barcelona in summer 2013, including two periods characterized by low and high traffic conditions. Volatile organic compound (VOC) concentrations were higher during the second period, especially aromatic hydrocarbons related to traffic emissions, which showed a marked daily cycle peaking during traffic rush hours, similarly to black carbon (BC) concentrations. Biogenic VOC (BVOC) concentrations showed only minor changes from the low to the high traffic period, and their intra-day variability was related to temperature and solar radiation cycles, although a decrease was observed for monoterpenes during the day. The organic carbon (OC) concentrations increased from the first to the second period, and the fraction of non-fossil OC as determined by (14)C analysis increased from 43% to 54% of the total OC. The combination of (14)C analysis and Aerosol Chemical Speciation Monitor (ACSM) OA source apportionment showed that the fossil OC was mainly secondary (>70%) except for the last sample, when the fossil secondary OC only represented 51% of the total fossil OC. The fraction of non-fossil secondary OC increased from 37% of total secondary OC for the first sample to 60% for the last sample. This enhanced formation of non-fossil secondary OA (SOA) could be attributed to the reaction of BVOC precursors with NOx emitted from road traffic (or from its nocturnal derivative nitrate that enhances night-time semi-volatile oxygenated OA (SV-OOA)), since NO2 concentrations increased from 19 to 42 µg m(-3) from the first to the last sample.
Assuntos
Aerossóis/análise , Poluição do Ar/análise , Combustíveis Fósseis/análise , Aerossóis/química , Radioisótopos de Carbono/química , Cidades , Cromatografia Gasosa-Espectrometria de Massas , Material Particulado/análise , Estações do Ano , Fuligem/química , Espectrofotometria Atômica , Luz Solar , Emissões de Veículos/análise , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/químicaRESUMO
Water-soluble organic compounds (WSOCs), represented by anhydro-saccharides, dicarboxylic acids, and polyols, were analyzed by gas chromatography interfaced to mass spectrometry in extracts from 103 PM1 and 22 PM2.5 filter samples collected in an urban background and road site in Barcelona (Spain) and an urban background site in Los Angeles (USA), respectively, during 1-month intensive sampling campaigns in 2010. Both locations have similar Mediterranean climates, with relatively high solar radiation and frequent anti-cyclonic conditions, and are influenced by a complex mixture of emission sources. Multivariate curve resolution-alternating least squares analyses were applied on the database in order to resolve differences and similarities in WSOC compositions in the studied sites. Five consistent clusters for the analyzed compounds were obtained, representing primary regional biomass burning organic carbon, three secondary organic components (aged SOC, isoprene SOC, and α-pinene SOC), and a less clear component, called urban oxygenated organic carbon. This last component is probably influenced by in situ urban activities, such as food cooking and traffic emissions and oxidation processes.
Assuntos
Aerossóis/análise , Cidades , Compostos Orgânicos/análise , Água/química , Monoterpenos Bicíclicos , Biomassa , Butadienos/análise , Hemiterpenos/análise , Humanos , Análise dos Mínimos Quadrados , Los Angeles , Monoterpenos/análise , Análise Multivariada , Material Particulado/análise , Pentanos/análise , Solubilidade , Espanha , Fatores de TempoRESUMO
PM1 aerosol characterization on organic tracers for biomass burning (levoglucosan and its isomers and dehydroabietic acid) was conducted within the AERTRANS project. PM1 filters (N = 90) were sampled from 2010 to 2012 in busy streets in the urban centre of Madrid and Barcelona (Spain) at ground-level and at roof sites. In both urban areas, biomass burning was not expected to be an important local emission source, but regional emissions from wildfires, residential heating or biomass removal may influence the air quality in the cities. Although both areas are under influence of high solar radiation, Madrid is situated in the centre of the Iberian Peninsula, while Barcelona is located at the Mediterranean Coast and under influence of marine atmospheres. Two extraction methods were applied, i.e. Soxhlet and ASE, which showed equivalent results after GC-MS analyses. The ambient air concentrations of the organic tracers for biomass burning increased by an order of magnitude at both sites during winter compared to summer. An exception was observed during a PM event in summer 2012, when the atmosphere in Barcelona was directly affected by regional wildfire smoke and levels were four times higher as those observed in winter. Overall, there was little variation between the street and roof sites in both cities, suggesting that regional biomass burning sources influence the urban areas after atmospheric transport. Despite the different atmospheric characteristics in terms of air relative humidity, Madrid and Barcelona exhibit very similar composition and concentrations of biomass burning organic tracers. Nevertheless, levoglucosan and its isomers seem to be more suitable for source apportionment purposes than dehydroabietic acid. In both urban areas, biomass burning contributions to PM were generally low (2 %) in summer, except on the day when wildfire smoke arrive to the urban area. In the colder periods the contribution increase to around 30 %, indicating that regional biomass burning has a substantial influence on the urban air quality.
Assuntos
Aerossóis/análise , Biomassa , Cidades , Incêndios , Compostos Orgânicos/análise , Material Particulado/análise , Estações do Ano , Monitoramento Ambiental/métodos , Glucose/análogos & derivados , Glucose/análise , Isomerismo , EspanhaRESUMO
Candida tropicalis ranks between third and fourth among Candida species most commonly isolated from clinical specimens. Invasive candidiasis and candidemia are treated with amphotericin B or echinocandins as first-line therapy, with extended-spectrum triazoles as acceptable alternatives. Candida tropicalis is usually susceptible to all antifungal agents, although several azole drug-resistant clinical isolates are being reported. However, C. tropicalis resistant to amphotericin B is uncommon, and only a few strains have reliably demonstrated a high level of resistance to this agent. The resistance mechanisms operating in C. tropicalis strains isolated from clinical samples showing resistance to azole drugs alone or with amphotericin B cross-resistance were elucidated. Antifungal drug resistance was related to mutations of the azole target (Erg11p) with or without alterations of the ergosterol biosynthesis pathway. The antifungal drug resistance shown in vitro correlated very well with the results obtained in vivo using the model host Galleria mellonella. Using this panel of strains, the G. mellonella model system was validated as a simple, nonmammalian minihost model that can be used to study in vitro-in vivo correlation of antifungals in C. tropicalis. The development in C. tropicalis of antifungal drug resistance with different mechanisms during antifungal treatment has potential clinical impact and deserves specific prospective studies.
Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Candida tropicalis/efeitos dos fármacos , Anfotericina B/farmacologia , Candida tropicalis/genética , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genéticaRESUMO
Blood biomarkers and levels of major pollutants in eggs and feathers were used to determine pollution effects in nestlings of the Purple Heron Ardea purpurea and the Little Egret Egretta garzetta, sampled on three Ebro River (NE Spain) areas: a reference site, a site affected by the effluents of a chlor-alkali industry and the river Delta. The two impacted heron populations showed mutually different pollutant and response patterns, suggesting different sources of contamination. In the population nesting near the chlor-alkali plant, elevated levels of hexachlorobenzene (HCB) and polychlorobiphenyls (PCBs) in eggs, and mercury in feathers in A. purpurea chicks were related with reduced blood antioxidant defenses and increased levels of micronuclei. In Ebro Delta, high levels of plasmatic lactate dehydrogenase in A. purpurea chicks and high frequency of micronuclei in blood of both species were tentatively associated with intensive agricultural activities taking place in the area. These results provide the first evidence of a biological response in heron chicks to the release of pollutants at a chlor-alkali plant.
Assuntos
Biomarcadores/sangue , Aves/fisiologia , Ovos/análise , Poluentes Ambientais/análise , Plumas/química , Animais , Aves/sangue , Poluentes Ambientais/sangue , Poluentes Ambientais/farmacologia , Feminino , Masculino , Mercúrio/análise , Testes para Micronúcleos , Comportamento de Nidação/efeitos dos fármacos , Bifenilos Policlorados/análise , EspanhaRESUMO
The presence of organochlorine compounds (OCs)-namely hexachlorobenzene (HCB), hexachlorocyclohexanes (HCH), polychlorobiphenyls (PCBs #28, 52, 101, 118, 138, 153 and 180), dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethane (DDE)-was examined in various fish tissues (muscle and liver) sampled in 23 mountain lakes in Europe. The dependence of these organochlorine compounds on geographical parameters (altitude, longitude, latitude and temperature) and physiological parameters (lipid content, age, weight and size) was assessed. Principal components analysis (PCA) and partial least squares (PLS) models were used for the analyses. PCA results showed that organochlorine compound concentrations in fish tissues increased with increasing altitude and decreasing temperatures. This trend appeared to be more marked for the less volatile compounds. Some differences were found between the muscle and liver in the effects of the percentage of lipids on the accumulation of organochlorine compounds and the behaviour of HCB. Moreover, PCBs tended to accumulate more in liver rather than in muscle. PCA scores clearly differentiated samples according to the lake of origin. PLS models confirmed that temperature and altitude were the main factors influencing the accumulation of most organochlorine compounds in the lipids of the fish tissue.
Assuntos
Peixes , Água Doce/química , Hidrocarbonetos Clorados/análise , Poluentes Químicos da Água/análise , Animais , Diclorodifenil Dicloroetileno/análise , Diclorodifenil Dicloroetileno/metabolismo , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Poluentes Ambientais/metabolismo , Europa (Continente) , Fungicidas Industriais/análise , Fungicidas Industriais/metabolismo , Hexaclorobenzeno/análise , Hexaclorobenzeno/metabolismo , Hidrocarbonetos Clorados/metabolismo , Inseticidas/análise , Inseticidas/metabolismo , Análise dos Mínimos Quadrados , Fígado/química , Fígado/metabolismo , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Bifenilos Policlorados/análise , Bifenilos Policlorados/metabolismo , Análise de Componente Principal , Poluentes Químicos da Água/metabolismoRESUMO
OBJECTIVE: Several studies have shown that some organochlorine compounds (OCs) can interfere with the thyroid system. As thyroid hormones (THs) are essential for normal brain development, it is important to study the association between THs and OCs during pregnancy and childhood. We have evaluated the relationship between thyroid function and OCs in preschool children. METHODS: Children from a general population birth cohort in Menorca (n = 259), Spain were assessed at the age of 4 years. Concentrations of THs (free T4 and total T3), thyrotropin (TSH) and a range of OCs were measured in peripheral blood. RESULTS: Blood levels of dichlorodiphenyl trichloroethane (p,p'-DDT), beta-hexachlorocylcohexane (beta-HCH), polychlorinated biphenyls (congeners PCB-138, PCB-153 and PCB-118) were related to lower total T3 levels (p<0.05). In addition, free T4 was inversely associated with PCB-118, while no relationship was found between TSH and any of the measured OCs. CONCLUSIONS: This study suggests that even at background levels of exposure, OCs may affect the thyroid system, particularly total T3 levels.
Assuntos
Poluentes Ambientais/toxicidade , Hidrocarbonetos Clorados/toxicidade , Doenças da Glândula Tireoide/induzido quimicamente , Pré-Escolar , DDT/toxicidade , Diclorodifenil Dicloroetileno/toxicidade , Exposição Ambiental , Feminino , Hexaclorobenzeno/toxicidade , Hexaclorocicloexano/toxicidade , Humanos , Lactente , Recém-Nascido , Masculino , Análise Multivariada , Bifenilos Policlorados/toxicidade , Estudos Prospectivos , Espanha , Doenças da Glândula Tireoide/sangue , Doenças da Glândula Tireoide/fisiopatologia , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/fisiopatologia , Hormônios Tireóideos/sangue , Tri-Iodotironina/sangueRESUMO
Our aims were to assess association of dichlorodiphenyldichloroethylene (DDE) with childhood asthma measured up to age 6 and the effect of DDE on the protective effect of breastfeeding on asthma. In addition, we attempted to assess the relevant time-window of DDE exposure (i.e. at birth or at 4 years). All women presenting for antenatal care in Menorca, Spain over a 12-month period beginning in mid-1997 were invited to take part in a longitudinal study that included a yearly visit. Four hundred eighty-two children were enrolled and 462 provided complete outcome data after 6.5 years of follow-up. Organochlorine compounds were measured in cord serum of 402 (83%) infants and in blood samples of 285 children aged 4. We defined asthma as the presence of wheezing at age 6 and during any preceding year or doctor-diagnosed asthma, and used skin prick test at age 6 to determine atopic status. Results At birth and 4 years of age, all children had detectable levels of DDE (median 1 ng/mL and 0.8 ng/mL, respectively). From birth to age 4, the mean DDE level among children with artificial feeding decreased by 72%, while among breastfed children it increased by 53%. Diagnosed asthma and persistent wheezing were associated with DDE at birth [odds ratio (OR) for an increase in 1 ng/mL, OR=1.18, 95% confidence interval (95% CI)=1.01-1.39 and OR=1.13, 95% CI=0.98-1.30, respectively], but not with DDE at 4 years. Neither breastfeeding nor atopy modified these associations (P>0.3). Breastfeeding protected against diagnosed asthma (OR=0.33, 95% CI=0.08-0.87) and wheezing (OR=0.53, 95% CI=0.34-0.82) in children with low and high DDE levels at birth. Conclusion In a community without known dichlorodiphenyltrichloroethane environmental releases, this study strengthens the evidence for an effect of DDE on asthma by measuring the disease at age 6 and does not support the hypothesis that DDE modifies the protective effect of breastfeeding on asthma.
Assuntos
Asma/prevenção & controle , Aleitamento Materno , Diclorodifenil Dicloroetileno/efeitos adversos , Inseticidas/efeitos adversos , Exposição Materna , Asma/etiologia , Asma/imunologia , Criança , Pré-Escolar , DDT/efeitos adversos , DDT/sangue , Diclorodifenil Dicloroetileno/sangue , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Hipersensibilidade/diagnóstico , Lactente , Recém-Nascido , Inseticidas/sangue , Modelos Logísticos , Masculino , Gravidez , Sons Respiratórios , Medição de Risco , Testes CutâneosRESUMO
BACKGROUND: Exposure to organochlorine compounds (OCs) has been a subject of interest in recent years, given their potential neurotoxicity. Meconium is easily available and accumulates neurotoxicants and/or metabolites from the 12th week of gestation. AIMS: To determine whether neurotoxicants, specifically OCs, could be detected in serially collected meconium, and to compare the results with those obtained in cord blood samples. METHODS: A sample of cord blood and three serial stool samples were analysed in 10 newborns. Pentachlorobenzene (PeCB), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethane (p,p'-DDT) and its metabolite dichlorodiphenyl dichloroethylene (p,p'-DDE), and hexachlorocyclohexane isomers (alpha-, beta-, gamma-, and delta-HCH) were analysed by gas chromatography. RESULTS: From serial stool collection and analysis in newborns, there was an increase in the concentrations of HCB, p,p'-DDE, PCBs, and beta-HCH between the first and last stools of the newborn. Levels of DDT diminished as pregnancy progressed. Concentrations in cord blood were positively associated with concentrations in meconium for p,p'-DDE and beta-HCH. CONCLUSIONS: Meconium is a very useful instrument for the investigation of fetal exposure to neurotoxicants; serial collection and analysis of meconium should estimate the timing and degree of in utero exposure of the fetus to neurotoxicants. Analysis and interpretation of neurotoxicants in meconium results is a complex process. Measurement in meconium of a wide range of neurotoxic substances should facilitate early identification of harmful exposures, and enable rehabilitation and instigation of preventive measures.
Assuntos
Sangue Fetal/química , Substâncias Perigosas/análise , Hidrocarbonetos Clorados/análise , Mecônio/química , Doenças do Sistema Nervoso/induzido quimicamente , Adulto , Feminino , Substâncias Perigosas/toxicidade , Humanos , Hidrocarbonetos Clorados/toxicidade , Recém-Nascido , Gravidez , Efeitos Tardios da Exposição Pré-NatalRESUMO
OBJECTIVES: To evaluate lifetime exposure to trihalomethanes (THM) through ingestion, inhalation, and dermal absorption in a hospital based case-control study of bladder cancer conducted between 1998 and 2001 in five areas of Spain. The study base was comprised of subjects living in the catchment areas of the participating hospitals. METHODS: Individual information on water related habits was obtained from personal interviews of 1219 cases and 1271 controls: residential and occupational history, drinking water source at each residence and job, amount of water consumption, frequency and duration of showering, bathing, and swimming pool attendance. THM levels, water source history, and year when chlorination started in study areas were ascertained through measurements in drinking water samples and questionnaires to water companies and local authorities. Estimates of THM levels covered 79% of the subjects' person-years of exposure. RESULTS: Current and historical average THM levels in water were correlated. Control subjects reported that drinking water source in the last residence was municipal for 63%, bottled for 22%, private well for 2%, and other sources for 13%. For the time window between age 15 and the time of interview, average residential THM level was 32.2 mug/l. THM exposure through ingestion was 23.7 mug/day on average, and was correlated with the ingestion THM level in the workplace. Overall, 79% usually took showers, 16% usually took baths, and 13% had ever attended a swimming pool. Between 21% and 45% of controls unexposed to THM through ingestion were evaluated as moderately or highly exposed through showering or bathing, and 5-10% were exposed through swimming in pools. CONCLUSION: The importance of evaluating different routes is underscored by findings from experimental studies showing substantial differences in THM uptake and internal distribution by route.
Assuntos
Exposição Ambiental/análise , Trialometanos/análise , Poluentes Químicos da Água/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Banhos/estatística & dados numéricos , Estudos de Casos e Controles , Feminino , Humanos , Exposição por Inalação/análise , Absorção Intestinal/fisiologia , Masculino , Pessoa de Meia-Idade , Características de Residência , Estudos Retrospectivos , Absorção Cutânea/fisiologia , Espanha/epidemiologia , Piscinas/estatística & dados numéricos , Neoplasias da Bexiga Urinária/epidemiologia , Purificação da Água/estatística & dados numéricos , Abastecimento de Água/análiseRESUMO
The massive oil discharge in the Saudi Arabian coast at the end of the 1991 Gulf War is used here as a natural experiment to study the ability of microbial mats to transform oil residues after major spills. The degree of oil transformation has been evaluated from the analysis of the aliphatic and aromatic hydrocarbons by gas chromatography (GC) and GC coupled to mass spectrometry (GC-MS). The oil-polluted microbial mat samples from coastal environments exhibited an intermediate degree of transformation between that observed in superficial and deep sediments. Evaporation, photo-oxidation and water-washing seemed to lead to more effective and rapid elimination of hydrocarbons than cyanobacteria and its associated microorganisms. Furthermore, comparison of some compounds (e.g. regular isoprenoid hydrocarbons or alkylnaphthalenes) in the oil collected in the area after the spill or in the mixtures retained by cyanobacterial growth gave rise to an apparent effect of hydrocarbon preservation in the microbial mat ecosystems.
Assuntos
Sedimentos Geológicos/química , Petróleo/metabolismo , Água do Mar/química , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Cromatografia Gasosa/métodos , Cianobactérias/metabolismo , Desastres , Cromatografia Gasosa-Espectrometria de Massas/métodos , Hidrocarbonetos Aromáticos/análise , Hidrocarbonetos Aromáticos/metabolismo , Petróleo/análise , Arábia Saudita , Água do Mar/microbiologia , Microbiologia da Água , Poluentes Químicos da Água/análiseRESUMO
The Ocean Anoxic Event 1 (OAE-1) in central sites of the Basque-Cantabrian Basin exhibits very reducing depositional conditions of sedimentation. These sedimentation events have left a distinct mixture of hydrocarbons that are represented by C22-C30 n-alkanes with a predominance of the even-carbon-number homologues, high relative proportions of squalane and C16-C24 n-alkylcyclopentanes predominated by n-undecyl-, n-tridecyl- and n-pentadecylcyclopentane. Other minor compounds encompass a series of C18-C21 n-alkylcyclohexanes and C18-C24 dimethyl n-alkylcyclohexanes maximized by the even-carbon-number homologues as well as iso- and anteiso-alkanes. This unusual distribution of n-alkanes in this environment provides a new case for comparison with previously reported hypersaline and phosphorite sedimentary deposits where the occurrence of similar n-alkane distributions was reported. In the present case, these major n-alkanes and squalane are indicative of transformation under strong reducing conditions. In contrast, the occurrence of the alkylcyclopentanes, irrespective of the presence of even-carbon-number n-alkanes or squalane, suggests that reductive cyclization of fatty acids is less dependent on strong reducing conditions.
RESUMO
Polychlorobiphenyls (PCBs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB) and DDT were examined in the muscle of brown trout (Salmo trutta) from a high mountain lake located in the Pyrenees (Catalonia, Spain) that was used as a model of these lacustrine environments. Results indicate that fish age is the main factor of variability among specimens in this population that is subjected to atmospheric inputs of the organochlorine compounds (OC). Increases of 2- and 20-fold between fish aged 1 year and 15 years old are found. The observed pattern cannot be explained in terms of fish size, condition factor, or muscle lipid content. Higher molecular weight compounds (higher lipophilicity) are better correlated with fish age than low molecular weight compounds. A transformation from 4,4'-DDT to 4,4'-DDE occurs in fish after ingestion; this results in amplified age-dependent signals, especially in male specimens. In contrast, PCB congener #180 has lower age dependence than the general OC group, which could be due to its high hydrophobicity (log K(ow) > 7). In any case, selective accumulation of hydrophobic compounds is already observed among younger fish (age, 1 year). Due to this effect, the relative OC composition does not reflect the main OC pollutants in the lake waters.
Assuntos
Hidrocarbonetos Clorados/análise , Músculos/química , Truta , Poluentes Químicos da Água/análise , Altitude , Animais , DDT/análise , DDT/farmacocinética , Exposição Ambiental/efeitos adversos , Feminino , Água Doce/química , Hexaclorobenzeno/análise , Hexaclorobenzeno/farmacocinética , Hexaclorocicloexano/análise , Hexaclorocicloexano/farmacocinética , Hidrocarbonetos Clorados/farmacocinética , Lipídeos/análise , Masculino , Músculos/metabolismo , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Fatores Sexuais , Espanha , Truta/metabolismo , Poluentes Químicos da Água/farmacocinéticaRESUMO
The uptake rates of selected hydrophobic organic contaminants (HOCs) by semipermeable membrane devices (SPMDs)--a polyethylene layflat containing the lipid triolein--were investigated under natural conditions. SPMDs were exposed in three sampling sites (industrial, urban, and agricultural areas) in the Tajo River (Toledo, Spain) for 5, 11 and 20 d. The organochlorine compounds 4,4'-DDT, 4,4'-DDE, alpha-HCH, gamma-HCH, pentachlorobenzene, hexachlorobenzene, and polychlorinated biphenyls (PCBs), and the 16 priority pollutant polycyclic aromatic hydrocarbons (PAHs) were detected in the SPMDs deployed in the three sampling sites. A linear uptake rate was found for DDTs and for 4-Cl- and 5-Cl-substituted PCB congeners in all sampling sites. Concentrations of HCHs (80.3 ng g(-1) SPMD for alpha-HCH and 109 ng g(-1) SPMD for gamma-HCH after 20 d of exposure) increased according to a linear uptake rate in the SPMDs deployed in the sampling site located in the agricultural area. Likewise, a marked increase of total PAH concentration (up to 300 ng g(-1) SPMD after 20 d of exposure) was solely found in the sampling site situated near a thermoelectric power station. Examination of individual PAHs revealed that PAHs with log K(OW) between 4.2 and 5.7 displayed a linear uptake rate over the 20 d of exposure. Water concentrations (ng L(-1)) of HCB (0.80-2.48), lindane (1.30-11.5), 4,4'-DDT (0.61-2.02), 4,4'-DDE (6.89-11.6) and total PAHs (12.0-26.7) estimated by a linear uptake kinetic model were found to be high in comparison with other polluted aquatic systems, and similar to concentrations in other Spanish rivers. Our results suggest that SPMD kinetic uptake studies in the natural environment are recommended for identifying point-pollution sources, and that shorter times of SPMD exposure (approximately 1 week) are desirable to minimize one of the main problems of field SPMD deployment, i.e., the biofouling, which negatively affects the estimation of the dissolved HOC concentrations.
Assuntos
Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Membranas Artificiais , Hidrocarbonetos Policíclicos Aromáticos/análise , Rios/química , Poluentes Químicos da Água/análise , Agricultura , Monitoramento Ambiental/instrumentação , Hidrocarbonetos Clorados/química , Interações Hidrofóbicas e Hidrofílicas , Indústrias , Hidrocarbonetos Policíclicos Aromáticos/química , EspanhaRESUMO
Polycyclic aromatic hydrocarbons (PAHs) were analysed in liver of fifty-seven individual trout distributed among seven high mountain lakes in Europe and one remote lake in Greenland. In all cases, very similar distributions were observed in which phenanthrene largely predominated and fluoranthene and pyrene were the second major compounds. These distributions were similar to those observed in the dissolved fraction of the waters studied in three of these lakes. The range of concentrations of PAH in fish liver show only a five-fold variation, which is considerably smaller than the range more than two orders of magnitude of sedimentary PAH concentrations of these lakes. No correlation between PAH content in sediments and fish liver has been found both at the level of total and individual compounds. However, lake site is the main statistically significant factor of variability between PAH concentrations in fish liver. Changes in fish species explain significant differences in liver content of some PAHs. Within lake, condition factor and liver concentration are inversely correlated. Female fish display lower average concentrations than male in all lakes but the differences are not statistically significant. No correspondence between fish age and PAH content has been observed.
Assuntos
Hidrocarbonetos Policíclicos Aromáticos/farmacocinética , Truta , Poluentes Químicos da Água/farmacocinética , Fatores Etários , Animais , Monitoramento Ambiental , Europa (Continente) , Feminino , Sedimentos Geológicos , Groenlândia , Fígado/química , Masculino , Hidrocarbonetos Policíclicos Aromáticos/análise , Fatores Sexuais , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: Renal allograft rupture is an early postoperative complication threatening graft and patient survival. We reviewed the etiology and prognostic factors for renal allograft rupture. MATERIAL AND METHODS: Among 657 renal transplants performed between 1990 and 2001, renal allograft rupture was diagnosed in 10 cases. Statistical analysis by Student t test, ANOVA, and chi-square was performed to assess donor and recipient characteristics. Multivariate logistic regression to predict renal allograft rupture used variables with P <.15 in the univariate analysis. RESULTS: Patients with renal allograft rupture were mainly men and young. Renal allograft rupture incidence was higher among allografts from non-heart-beating donors, kidneys with delayed graft function, or patients with a high antibody titer. Histopathological findings revealed that six renal allograft ruptures were secondary to acute rejection, three to acute tubular rejection and one to allograft infarction. Only one of six renal allograft ruptures (17.7%) secondary to rejection was resolved by surgery; two of the three patients (66.7%) with acute tubular necrosis were successfully operated and a nephrectomy was performed for the patient with allograft infarction. By multivariate logistic regression analysis, factors shown to be predictive for renal allograft rupture were: delayed graft function, age of recipient, peak panel-reactive antibody >25%, and initial immunosuppressive treatment without antithymocyte globulin. CONCLUSIONS: Higher graft salvage rates are possible in cases of graft rupture associated with acute tubular necrosis.
Assuntos
Transplante de Rim/efeitos adversos , Transplante de Rim/patologia , Túbulos Renais/patologia , Complicações Pós-Operatórias/terapia , Ruptura , Terapia de Salvação/métodos , Adulto , Feminino , Humanos , Isoanticorpos/sangue , Masculino , Estudos Retrospectivos , Transplante Homólogo/efeitos adversos , Transplante Homólogo/patologiaRESUMO
The population of Flix (region of Ribera del Ebro, Tarragona) is highly exposed to hexachlorobenzene (HCB) due to the closeness of an electrochemical factory. Although the degree of HCB contamination in this population is still high, concentrations of HCB in the sera of women aged 18-40 years from 1997 to 1999 were 61% lower than those observed in 1994 (4.1 ng/ml vs. 10.6 ng/ml). Concentrations of dichlorodiphenyl dichloroethane (p,p'-DDE) and beta-hexachlorocyclohexane (beta-HCH) also decreased, although the difference was not statistically significant. In contrast, concentrations of polychlorinated biphenyls (PCB) in the period 1997-1999 showed a nonsignificant increase compared with those in 1994.