A Pla

University of Granada, Granata, Andalusia, Spain

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Publications (67)142.67 Total impact

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    ABSTRACT: In this study, levels of copper, manganese, selenium and zinc have been determined in fresh, canned and frozen fish and shellfish products. A total of 485 samples of fish and shellfish species from Andalusia (Southern Spain) were analyzed for essential elements content. The potential human health risks for the consumers and the nutritional value of the products analyzed were assessed. Furthermore, the mercuryselenium ratios and the selenium health benefit value (Se-HBVs) were calculated. The highest concentrations of copper were found in crustaceans species (shrimp and prawn). Manganese levels were higher in canned bivalve molluscs, such as cockle and clam, and in fresh common sole. Concerning selenium, two fresh predatory fish species (tuna and swordfish) presented the most remarkable concentrations of this element. The highest concentration of the essential metals analysed was found for zinc, especially in fresh and canned mussels. All the species analyzed showed beneficial Hg:Se ratios and Se-HBVs, except for the shark species and gilt-head bream because of their high Hg levels and low Se content, respectively. The estimated daily intakes of the elements studied represented very low percentages of their reference values (0.1-3.9%), so they would not pose any risk for the average consumer.
    Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 09/2013; · 2.99 Impact Factor
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    ABSTRACT: Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead).
    Environment international 06/2013; 59C:63-72. · 6.25 Impact Factor
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    ABSTRACT: This study evaluated the association between pesticide exposure in farmworkers and plasma levels of the endogenous antioxidants urate and paraoxonase-1 (PON1) enzyme activities (paraoxonase, arylesterase and diazoxonase, three substrate-specific assays for measuring PON1 function) by using generalized estimating equations (GEE). Decreases in plasma and erythrocyte cholinesterases (BChE and AChE, respectively) were used as biomarkers of pesticide exposure. We also assessed the contribution of genetic polymorphisms of the pesticide-metabolising enzymes PON1, glutathione-Stransferases (GST) and cholinesterase variants (BCHE) on plasma levels of endogenous antioxidants and potential gene-environment interactions. A dual effect was observed on paraoxonase depending on the pattern of pesticide exposure. Thus, exposure to anticholinesterase pesticides was associated with decreased paraoxonase activity and urate levels whereas long-term pesticide exposure showed an association with increased paraoxonase activity. Significant interactions were observed between BChE activity and PON1 regulatory region polymorphisms on arylesterase and diazoxonase activities, and between AChE activity (a biomarker for long-term pesticide exposure) and PON1192RR genotype on arylesterase activity. These findings suggest that pesticide exposure may affect plasma antioxidant potential and that relevant gene-pesticide interactions may play a mechanistic role in oxidative stress-induced diseases following pesticide exposure. Nonetheless, more studies are needed to better characterise these interactions.
    Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 06/2013; · 2.99 Impact Factor
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    ABSTRACT: Previously we reported that intensive agriculture workers exposed to pesticides had decreased levels of the intraerythrocyte enzymes delta-9-aminolevulinic acid dehydratase (ALA-D) and superoxide dismutase (SOD), very likely as a result of pesticide-induced oxidative stress. We have now examined in this population potential gene-environment interactions by modeling generalized estimating equations (GEE) adjusted for age, sex, body mass index and tobacco and alcohol consumption. Particularly, we assessed the interaction effects between plasma and erythrocyte cholinesterases (BChE and AChE, used as proxies for short- and long-term pesticide exposure, respectively) and a number of genetic polymorphisms of pesticide metabolizing enzymes such as paraoxonase-1 (PON1), glutathione-S-transferases (GST) and plasma cholinesterase variants (BCHE) on levels of erythrocyte antioxidant enzymes (SOD, catalase, glutathione peroxidase, glucose-6-phosphate dehydrogenase and ALA-D). We observed significant interaction effects between BChE activity and PON1(192R) allele on catalase, glutathione peroxidase and glucose-6-phosphate dehydrogenase activities. BChE also interacted significantly with GSM1 null genotype on ALA-D and SOD. Regarding long-term pesticide exposure, a significant interaction was found between AChE and genotypes PON1(192QR) and PON1(108CC) on GR; between AChE and PON1(192RR) on SOD, and between AChE and GSTM1, GSTT1 and unusual BCHE variants on catalase activity. These findings suggest relevant gene-pesticide interactions and highlight the potential role of genetic risk factors in the pathomechanism of oxidative stress-induced degenerative diseases following pesticide exposure.
    Toxicology 09/2012; · 4.02 Impact Factor
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    ABSTRACT: A simple, rapid and sensitive method has been developed and validated for the determination of cocaine and its main metabolites (benzoylecgonine and cocaethylene) in human hair. The method involved solid-phase extraction with an Oasis HLB extraction cartridge and subsequent analysis by GC/MS. The limit of detection was 0.01 ng mg(-1) for cocaine, 0.04 for benzoylecgonine and 0.03 for cocaethylene. The method validation included linearity (with a correlation coefficient >0.99 over the range 0.2-50 ng mg(-1) ), intra- and inter-day precision (always lower than 12%) and accuracy (mean relative error always below 17%) to meet the bioanalytical acceptance criteria. The procedure was further applied to 40 hair samples from self-reported cocaine users arrested by the police who provided a positive urine-analysis for cocaine, and was demonstrated to be suitable for its application in forensic toxicology. New approaches were raised to detect false-negative results that allow a better interpretation of hair testing results. Copyright © 2012 John Wiley & Sons, Ltd.
    Journal of Applied Toxicology 03/2012; · 2.60 Impact Factor
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    ABSTRACT: Los avances científicos y tecnológicos registrados en la última década han propiciado un conocimiento cada vez más profundo de las bases genéticas y moleculares de las enfermedades y de la variabilidad en la respuesta (terapéutica o tóxica) a fármacos de unas personas a otras. Así, tras la administración de una misma dosis de fármaco o droga, la respuesta fármaco-toxicológica y la concentración plasmática varía de unos individuos a otros. Este fenómeno explica por qué una importante proporción de personas o no responden, o lo hacen de forma insuficiente o experimentan reacciones adversas. Estas diferencias pueden ser de base genética, ambiental o fisiopatológica. Aunque solo las primeras son el objeto de esta presentación, hay que tener en cuenta también la contribución de los fenómenos de inducción e inhibición enzimáticas (especialmente de citocromos P450, CYP450) derivados de la exposición ambiental o nutricional a sustancias químicas (p.ej., humo de tabaco, consumo de alcohol, zumo de pomelo) o la administración simultánea de varios medicamentos (antibióticos, antifúngicos, anticonvulsivantes, etc.). Asimismo, diferencias fisiológicas (edad, sexo, embarazo) y fisiopatológicas (disfunción hepática, renal o de otros órganos diana) contribuyen también a la variabilidad de la respuesta terapéutica o tóxica entre individuos con similar exposición. En general, los factores genéticos suponen entre el 15 y el 30% de las diferencias interindividuales en el metabolismo y respuesta a fármacos y drogas, aunque en algunos casos pueden llegar hasta el 95%.
    Revista de Toxicologia. 07/2011; 28(1-Volumen 28, Número 1):16-17.
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    ABSTRACT: Heavy metal contamination from occupational origin is a cause for concern because of its potential accumulation in the environment and in living organisms leading to long term toxic effects. This study was aimed to assess Cd, Cr, Mn, Ni and Pb levels in whole blood, urine, axillary hair and saliva from 178 individuals with occupational exposure to heavy metals. Levels of metal compounds were determined by atomic absorption spectrometry. We collected information on occupation, lifestyle habits and food intake by questionnaire. Multiple linear regression analyses for metal ion concentration in whole blood, urine, axillary hair and saliva were adjusted for age, gender, smoking and alcohol consumption, lifetime workplace exposure, residence area and food habits. Overall, blood and urine median concentrations found for the five metals analyzed do not exceed biological exposure indexes, so that they are very similar to a non-occupationally exposed population. Toxicokinetic differences may account for the lack of correlations found for metal levels in hair and saliva with those in blood or urine. For those heavy metals showing higher median levels in blood with respect to hair (Cd, Mn and Pb) indicating lesser hair incorporation from blood, the lifetime working experience was inversely correlated with their hair levels. The longer the lifetime working experience in industrial environments, the higher the Mn and Ni concentration in saliva. Axillary hair and saliva may be used as additional and/or alternative samples to blood or urine for biomonitoring hair Mn, and saliva Ni in subjects with occupational exposure.
    Science of The Total Environment 02/2011; 409(6):1172-80. · 3.26 Impact Factor
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    47th Congress of the European Societies of Toxicology (EUROTOX); 01/2011
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    Rev. Toxicol. 01/2011; 28:16-17.
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    ABSTRACT: The Ria of Huelva (south-west Spain) is a highly polluted estuary as a consequence of long-term mining and industrial activities. Between 2003 and 2004, we conducted a biomonitoring study of exposure to arsenic and some heavy metals (cadmium, chromium, copper and nickel) in urine samples of a representative sample (n=227) of children and adolescents residing in this area, and of a reference group of 196 children and adolescents living in other less industrialised areas of Andalusia (south Spain). We also assessed the determinants of the variability in urinary metals within the population of the Ria of Huelva. There were no significant differences in the concentration of metal compounds between the two groups with the exception of Cd levels, which were significantly higher in the reference group. Levels of the five metal ions in both groups were generally within the range of values reported by other biomonitoring studies for general children population, although mean Cd levels tended to be higher as compared to other European studies. Among the population of the Ria of Huelva, the main determinants of the interindividual variation in urinary metals were age, sex, area of residence, and frequency of intake of certain food items (mainly fish and shellfish). Overall, results suggest that living in the Ria of Huelva is not increasing current levels of exposure to certain metals among children and adolescents above those found in other urban areas of Andalusia.
    Environment international 08/2010; 36(6):563-9. · 6.25 Impact Factor
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    ABSTRACT: For biological monitoring of heavy metal exposure in occupational toxicology, usually whole blood and urine samples are the most widely used and accepted matrix to assess internal xenobiotic exposure. Hair samples and saliva are also of interest in occupational and environmental health surveys but procedures for the determination of metals in saliva and hair are very scarce and to our knowledge there is no validation of a method to quantify Cr, Cd, Mn, Ni and Pb in four different human biological materials (whole blood, urine, saliva and axilary hair) by electrothermal atomization atomic absorption spectrometry (ETAAS). In the present study, quantification methods for the determination of Cr, Cd, Mn, Ni and Pb in whole blood, urine, saliva and axilary hair were validated according to the EU common standards. Pyrolisis and atomization temperatures have been determined. The main parameters evaluated were: detection and quantification limits, linearity range, repeatability, reproducibility, recovery and uncertainty. Accuracy of the methods was tested with the whole blood, urine and hair certified reference materials and recoveries of the spiked samples were acceptable ranged from 96.3 to 107.8%.
    Analytica chimica acta 02/2010; 659(1-2):60-7. · 4.31 Impact Factor
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    Rev. Toxicol. 01/2010; 27(1-2):21-23.
  • Toxicology Letters - TOXICOL LETT. 01/2010; 196.
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    ABSTRACT: Paraoxonase-1 (PON1) and cholinesterase (BChE) are two of the major human serum esterases. Although most of variation in PON1 activity results from genetic factors, there is growing evidence that environmental chemicals also modulate its activity. The aim of this study was to investigate whether environmental exposure to metal compounds has any influence on those esterases. A cross-sectional study was conducted in a representative sample of the general population of Andalusia, South of Spain. PON1 activity against different substrates (paraoxon, phenylacetate, diazoxon and dihydrocoumarin) and BChE were measured in serum from 536 healthy subjects. Potential associations of these esterases with metal compounds, age, sex and body mass index as well as life-style habits (smoking, alcohol drinking and food habits) were explored. Multiple linear regression analysis showed that blood lead levels were significantly associated with increased PON1 in serum regardless of the substrate used for the assay. Mercury also showed a significant and direct association with PON1 towards paraoxon and phenylacetate. In turn, cadmium and zinc levels were significantly associated with a decreased PON1 activity (zinc was associated with all PON1 activities and cadmium with PON1 towards paraoxon and diazoxon). Arsenic, nickel and manganese failed to be significantly associated with any of the PON1 activities assayed. PON1 192R alloform predicted significantly higher levels of arsenic and lead. BChE, however, was inversely associated with serum levels of manganese and zinc. These results suggest that PON1 and BChE activities are modulated by background exposure to metal compounds, which may have implications in public health given the defensive role played by both enzyme proteins against environmental toxicants. The potential underlying mechanisms merit further investigation.
    NeuroToxicology 05/2009; 30(4):628-35. · 2.65 Impact Factor
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    ABSTRACT: The common mixture for smoke bombs contains zinc oxide and a chlorine donor, which allows for the formation of fine particles of zinc chloride. We report a fatal case of exposure to a smoke bomb used for a fire training exercise at a school. A 21-year-old student inhaled zinc oxide/hexachloroethane from a smoke bomb during a fire simulation at a school. Fever and tachypnea began six hours after exposure. Radiological evaluation showed a mixed interstitial-alveolar bilateral infiltrates. Despite supportive care, the patient died of multi-organ failure nine days after inhalation. ZnCl inhalation is characterized by a lag period between exposure and evidence of respiratory toxicity, ranging from ten to 32 days, depending on the inhaled dose of ZnCl. Subjects inhaling even a small amount of aerosols from a smoke bomb should be carefully managed in a hospital setting where their respiratory function can be closely monitored. This case highlights the risk of serious injury and even death from smoke bombs containing zinc chloride aerosol in schools and suggests that these smoke bombs should not be used for fire simulation or activities where human exposure is suspected, particularly in schools.
    Clinical Toxicology 08/2008; 46(6):563-5. · 2.59 Impact Factor
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    ABSTRACT: Pesticides may contribute to adverse respiratory health effects among farmers and have been considered one causal factor for the rise in asthma prevalence. This cross-sectional study was conducted to evaluate potential respiratory function abnormalities following long-term pesticide exposure by means of a complete pulmonary function testing, including spirometry, lung volumes, and diffusing capacity for carbon monoxide. The study population was comprised by workers from a prominent intensive agriculture area of southern Spain that relied on pesticides for the control of plagues. Eighty-nine pesticide sprayers of plastic greenhouse farming and a control group of 25 nonspraying control farmers from the same area were interviewed by a general practitioner asking about sociodemographic factors, occupational exposure, and clinical symptoms by using a structured questionnaire. Multiple regression analyses showed a relationship of short-term exposure to pesticides (as indicated by a drop in serum cholinesterase > 25% of baseline levels) with reduced forced expired volume in 1 s, and of long-term exposure (as indicated by a cumulative pesticide exposure index) with reduced forced expiratory flow rate. Exposure to bipyridilium-class herbicides was a determinant of a fall in the diffusing capacity of the lungs, and neonicotinoid insecticides showed a relationship with lower pulmonary volumes (total lung capacity, residual volume, and functional residual capacity), suggestive of restrictive lung disease, and with an increased risk of reporting irritative symptoms.
    Inhalation Toxicology 07/2008; 20(9):839-49. · 1.89 Impact Factor
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    ABSTRACT: To determine the incidence of the detection of abuse drugs in severe trauma patients Prospective observational study conducted from July 2004 to January 2006. Neurotrauma intensive care unit of a reference tertiary university hospital. Trauma patients who require admission to ICU during the study period. Determination of alcohol in blood and of toxics (cocaine, cannabis, amphetamines and other substances) in urine. Toxicological analysis was performed in 196 of the 288 severe trauma patients admitted during the study period. The most frequently detected cause of the trauma was traffic accident (69%). The most frequently detected substance was cannabis (22.4%), followed by alcohol (17.3%) and cocaine (12.8%). Cannabis was detected in 26.1% of under-45-yr-old patients versus 9.3% of older patients (p < 0.05), and cocaine in 16.3% vs. 0% in over-45-yr-olds (p < 0.001). Some substance of abuse was detected in 45% of under-45-yr-olds versus 23% of older patients (p < 0.05). The high proportion of positive results to toxic substances in severely traumatized patients suggests that the epidemiological environment for these patients is of great concern. These data may be of interest for the design of future prevention campaign.
    Medicina Intensiva 07/2008; 32(5):222-6. · 1.32 Impact Factor
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    ABSTRACT: Objective To determine the incidence of the detection of abuse drugs in severe trauma patients. Design Prospective observational study conducted from July 2004 to January 2006. Setting Neurotrauma intensive care unit of a reference tertiary university hospital. Patients Trauma patients who require admission to ICU during the study period. Interventions. Determination of alcohol in blood and of toxics (cocaine, cannabis, amphetamines and other substances) in urine. Results Toxicological analysis was performed in 196 of the 288 severe trauma patients admitted during the study period. The most frequently detected cause of the trauma was traffic accident (69%). The most frequently detected substance was cannabis (22.4%), followed by alcohol (17.3%) and cocaine (12.8%). Cannabis was detected in 26.1% of under-45-yr-old patients versus 9.3% of older patients (p < 0.05), and cocaine in 16.3% vs. 0% in over-45-yr-olds (p < 0.001). Some substance of abuse was detected in 45% of under-45-yr-olds versus 23% of older patients (p < 0.05). Conclusion The high proportion of positive results to toxic substances in severely traumatized patients suggests that the epidemiological environment for these patients is of great concern These data may be of interest for the design of future prevention campaign.
    Medicina Intensiva 01/2008; 32(5):222-226. · 1.32 Impact Factor
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    ABSTRACT: The Ria of Huelva (south-west Spain) is one of the most polluted fluvial-estuarine systems in the world. Industrial activity delivers huge amounts of pollutants to the local environment, particularly heavy metals and arsenic. Here we aimed to determine urinary levels of As, Cd, Cr, Cu and Ni in a representative sample (n = 857) of adults living in the Ria of Huelva. Levels were compared to those from a representative sample of 861 adults of the general urban population of Andalusia (southern Spain) and multiple regression models were developed to identify individual factors associated with urinary levels of these elements. Arsenic levels were significantly higher in the Ria of Huelva as compared to other Andalusian cities, whereas Cd and Ni levels were significantly lower. Despite these differences, levels in both groups were similar to the reference values reported in previous studies for general population. Age, gender, diet and lifestyle were the major factors contributing to the interindividual variation in urinary metals. In conclusion, despite living in a highly polluted area, the population of the Ria of Huelva failed to show higher urinary levels of the studied metals as compared to a reference urban population of the same region.
    Science of The Total Environment. 01/2008;
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    ABSTRACT: Paraoxonase-1 (PON1) is known to play an important role in the individual susceptibility to environmental chemicals, particularly pesticides. The major results of our studies on biochemical and clinical end-points of workers long-term exposed to pesticides in a large intensive agriculture area from Southeast Spain are presented herein and compared with several other epidemiologic studies performed in different scenarios. In addition of being an individual marker of susceptibility, PON1 can be also considered a biological indicator of exposure to pesticides, since workers spraying these agents (chiefly OPs) showed decreased enzyme levels. Besides, long-term exposure to pesticides appears to indirectly elicit higher levels of PON1, which might be regarded as enzyme induction. On the other hand, carriers of the PON1 192R allele showed lower levels of erythrocyte cholinesterase and catalase, but a higher glutathione reductase activity. Regarding clinical outcomes, workers with the PON1 R allele had less risk of reporting a previous episode of pesticide poisoning as well as a lower risk of pesticide-related symptomatology. Exposure to low doses of pesticides which are metabolically activated in the liver seems to elicit subtle and early biochemical changes of hepatotoxicity. It is concluded that epidemiological studies addressing health or biochemical outcomes of workers occupationally exposed to pesticides should determine PON1 genotypes and phenotypes (activities), as these biomarkers may help in identifying those individuals at increased risk of developing pesticide toxicity or who are showing early effects after pesticide exposure
    12/2007: pages 221-237;