Hair mercury is associated with dyslipidemia and cardiovascular risk: An anthropometric, biochemical and genetic cross-sectional study of Amazonian vulnerable populations.

This cross-sectional study evaluated the association between human exposure to mercury and cardiovascular risk using lipid profile (including apolipoproteins) and genetic analysis of Amazonian riverine population. Anthropometric data (gender, age, height, weight, blood pressure, and neck and waist circumferences) of the participants were recorded. Total mercury and methylmercury (MeHg) content were quantified in hair by ICP-MS and GC-pyro-AFS system. Polymorphisms rs662799, rs693, rs429358 and rs7412 (of genes of apolipoproteins A-V, B, and E at positions 112 and 158, respectively) were genotyped by real-time PCR. The population presented a dyslipidemia profile significantly correlated with high mercury levels. The apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) index was also positively correlated with mercury, supporting a possible causal relationship. Allelic distributions were similar to those described in other populations, suggesting that genetic susceptibility may not have a significant role in the lipid alterations found in this work. This study demonstrated for the first time: i) the relationship between mercury exposure and cardiovascular risk-related apolipoproteins in humans, ii) the ApoB levels and the ApoB/ApoA-I index as the risk factors more strongly associated to the mercury-related dyslipidemia in humans, and iii) the prevalence of high/moderate risk of acute myocardial infarction in the vulnerable and chronically exposed-populations of the Amazon, in addition to the genotypic profile of the three most frequent polymorphisms in apolipoproteins of relevance for cardiovascular risk. This early detection of lipid alterations is essential to prevent the development of cardiovascular diseases (CVD), especially in chronically exposed populations such as those found in the Amazon. Therefore, in addition to provide data for the Minamata Convention implementation, our work is in line with the efforts joined by all members of the World Health Organization committed to reducing premature deaths originating from non-communicable diseases by 25% in 2025, including CVD.

Rapid assessment of silver nanoparticle migration from food containers into food simulants using a qualitative method.

Migration of silver nanoparticles (AgNPs) from food containers (FCs) has been assessed for the first time using a screening method previously validated. Migration was evaluated using water and 3% acetic acid as food simulants (FSs), from 20 to 70 °C at contact times of 2 h and 10 days. Total and migrated Ag were determined by inductively coupled plasma-mass spectrometry (ICP-MS) in the FCs and FSs, respectively. Then, the screening method was validated, and probability of detection (POD) curves were constructed in both FSs to characterize the response to AgNPs. The results provided by the present screening method showed no release of AgNPs. The FSs in contact with FCs were spiked at levels above, inside and below the unreliability region, with a reliability rate (RLR) of 0.90. Asymmetric flow field flow fractionation coupled to inductively coupled plasma mass-spectrometry (AF4-ICP-MS) was used for confirmative analyses.

Nutrient enrichment and trace element accumulation in sediments caused by waterbird colonies at a Mediterranean semiarid floodplain.

Waterfowl are vectors of nutrients, metals, and other pollutants (i.e. PCBs and microorganisms) on wetlands and other water bodies, especially when bird population density is high, e.g., in nesting, roosting or breeding periods. This work reports the effects caused by the increase in breeding pairs of herons and cormorants between 2010 and 2014 on sediments in an eutrophic Mediterranean wetland belonging to La Mancha Húmeda Biosphere Reserve. Nutrients, metals, metalloids, and isotopic composition (δ15N and δ13C) were analysed in sediments and faeces at several points in the Tablas de Daimiel National Park (TDNP), as well as in the nearby Navaseca wetland, which receives inputs from a wastewater treatment plant (WWTP). Sediments from Navaseca and from one site that is affected by heron colonies (Garcera) in the TDNP showed higher concentrations of organic matter, total organic carbon, total nitrogen, total phosphorus, Al, Co, Cu, Cr, Fe, Ni and Zn than the rest of the sampling sites. Significant correlations between these variables were found, probably suggesting that they have a common organic source. The highest δ15N values in sediments of the TDNP were registered in Guadiana, a site where there is no impact from colonies; these values might therefore be due to anthropogenic activities. Metal and metalloid content in sediments was lower than the regional reference values in soils, except for Se in the TDNP, and Zn and Cu in Navaseca. High Se level in TDNP sediment may be caused by seleniferous soils located upstream. Results showed a low impact of bird droppings compared to other sources of nutrients in the annual input in the TDNP.

Screening-confirmation strategy for nanomaterials involving spectroscopic analytical techniques and its application to the control of silver nanoparticles in pastry samples.

The full characterization of nanomaterials (NMs), which requires a range of different and expensive equipment, is not always necessary to meet certain demands of information. Qualitative analytical methods are ideal alternatives when only a piece of information is required. In this work, a qualitative method for the screening of NMs has been developed and statistically validated for the first time, with silver nanoparticles (AgNPs) as a proof of concept. It is based on the generation of chemiluminescence of the luminol/Ag+ system in alkaline media in the presence of AgNPs. Measurements are obtained in a short time with a simple instrument. Probability of detection (POD) curves were constructed at three cut-off values next to the limit of detection of the chemiluminescent method. The unreliability region (UR) was from 0.50 to 1.82 µg L-1. Currently, no regulation on AgNPs exists, but the present method was successfully tested for a hypothetical threshold of 2.5 µg L-1 of 40 nm AgNPs. The method was applied to silver colored pearls, with silver (E-174) or aluminum (E-173) coating, used for decoration of pastry. Performance parameters such as false negative and positive rates as well as specificity, sensitivity and reliability rates were calculated for validation. The results of the screening method were confirmed by asymmetric flow field flow fractionation coupled to inductively coupled plasma mass spectrometry (AF4-ICP-MS). The proposed screening method is simple, fast, economic, and easy to transfer to routine laboratories in the field of food safety.

Simultaneous extraction and preconcentration of monomethylmercury and inorganic mercury using magnetic cellulose nanoparticles.

Magnetite (Fe3O4) nanoparticles were modified with nanocellulose and are showed to be a useful sorbent for magnetic solid-phase extraction of mercury species. Speciation analysis was performed by using gas chromatography coupled to atomic fluorescence detection (GC-pyro-AFS). The magnetic properties of the sorbent make this approach simple and rapid, and the use of a renewable and biodegradable nanomaterial (nanocellulose) makes it environmentally friendly. The factors that affect adsorption (pH value, amount of nanomaterial, time, volume of sample) and desorption (solvent, time) have been optimized. Both desorption and derivatization of mercury species were performed in a single step. This reduces considerably the sample preparation time. Under the optimized conditions, the limits of detection are 4.0 pg mL-1 for monomethylmercury and 5.6 pg mL-1 for inorganic mercury. The repeatability and reproducibility are satisfactory. The method enables inorganic mercury and monomethylmercury to be simultaneously extracted, with preconcentration factors up to 300. The potential interferences of organic matter and/or co-existing ions were also investigated using synthetic waters. The procedure was applied to the analysis of tap water and river water samples with different characteristics from a mercury polluted area (Almadén, Spain). The extraction recoveries ranged from 81 to 98% regardless of the type of water, which demonstrates the applicability of the method. This is the first time that this kind of sorbent is used for trace metal speciation. Graphical abstract Schematic representation of the new composite material (made of Fe3O4 magnetic nanoparticles and cellulose fibers, MCNPs) for the simultaneous extraction and preconcentration of mercury species taking advantage of the magnetic properties of this eco-friendly sorbent.

Magnetic cellulose nanoparticles as sorbents for stir bar-sorptive dispersive microextraction of polychlorinated biphenyls in juice samples.

Magnetic cellulose nanoparticles (MCNPs) were used for the first time as sorbents for stir bar-sorptive dispersive microextraction (SBSDME). The main experimental parameters involved in the SBSDME process that affect extraction (i.e. amount of MCNPs, ionic strength, pH, extraction and back-extraction time) were investigated. The method was applied to the determination of nine polychlorinated biphenyls (PCBs) in fruit juice samples by gas chromatography-mass spectrometry (GC-MS). Under the optimized conditions, a good linearity was obtained in a concentration range of 10-1000 ng mL-1 with determination coefficients over 0.9945. Limits of detection and quantification for all target PCBs were in the range 2.1-54 ng L-1 and 7.0-180 ng L-1, respectively. Intra-day precision ranged from 1.7% to 8.8% and inter-day precision from 3.4% to 9.3% RSD. The enrichment factors of the analytes were from 74.6 to 98.2. The MCNPs can be reused up to 5 times. The method was applied to commercial orange and pineapple juices (n = 5), where concentrations were below the limits of detection. Recoveries from 70.4 to 108.0% were obtained by applying the method for the analysis of spiked fruit juice samples at 1 and 2 ng mL-1 concentration levels. The use of cellulose makes this approach environmentally friendly and the magnetism of the resulting sorbent in conjunction with SBSDME provides ease of handling and saving of time.

Analytical metrology for nanomaterials: Present achievements and future challenges.

Nanoscience and nanotechnology have emerged in recent years as revolutionary trends in almost all fields of activity. Their impact has taken place in the analytical science, too. Firstly, because the use of nanomaterials as analytical tools is more and more frequent and secondly, because the analytical control of nanomaterials in a wide variety of samples is required. In both aspects, analytical metrology for nanomaterials is involved as the scientific discipline responsible for providing reliable information (based on experimental measurements) to end users. This review presents a general view of the present achievements and the future challenges of analytical metrology for nanomaterials. Selected references and a critical discussion are reported for illustrating this important role of the metrology applied to nano-world.

Metals and metalloids in blood and feathers of common moorhens (Gallinula chloropus) from wetlands that receive treated wastewater.

We addressed the hypothesis that birds in eutrophic wetlands receiving wastewater treatment plant (WWTP) effluents are exposed to high levels of metals and metalloids and this may drive an ecological trap in some species attracted to these highly productive ecosystems. Levels of metals and metalloids were determined in sediment and in blood and feathers of common moorhens (Gallinula chloropus) from two wetlands in Central Spain: Navaseca Pond, which receives directly the effluent of a WWTP; and Tablas de Daimiel National Park, which is a floodplain less affected by urban discharges. Sediment concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb were higher in Navaseca Pond than in Tablas de Daimiel; only Se was higher in Tablas de Daimiel than in Navaseca. Blood levels of Hg and Se were higher in moorhens from Tablas de Daimiel than those from Navaseca. In the case of Hg these levels were below the threshold of adverse effect, but Se levels in 24% of moorhens from Tablas de Daimiel were above the threshold value associated with Se toxicity in birds (1000 ng/mL). In feathers, Hg, Se, Mn, Cu and As levels were higher in Tablas de Daimiel than in Navaseca. Body condition of moorhens was negatively associated with blood Se levels in the moorhens from Tablas de Daimiel. We can reject the hypothesis of a higher accumulation of metals and metalloids in birds associated with the WWTP effluent, but Se levels may need further research considering the nature of the floodplain of Tablas de Daimiel National Park.

Ionic liquid dispersive liquid-liquid microextraction combined with LC-UV-Vis for the fast and simultaneous determination of cortisone and cortisol in human saliva samples.

Ionic liquid dispersive liquid-liquid microextraction (IL-DLLME) was used for the first time for the extraction and preconcentration of cortisone and cortisol from human saliva samples. This approach allows the determination of both compounds by liquid chromatography (LC) with ultra-violet/visible (UV/Vis) detection at physiological levels. The IL 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6] and methanol (MeOH) were used as extraction and dispersive solvents, respectively. The parameters that affect extraction (ionic strength, pH, amount of IL, volume of dispersive solvent, vortex and centrifugation time) were optimized. Limits of detection were 0.11 (cortisone) and 0.16 µg L-1 (cortisol) and enrichment factors of 5.0 (cortisol) and 6.3 (cortisone) were achieved. Recoveries from 83.3 ± 1.6 to 115.8 ± 3.0% were obtained for the extraction of the target analytes in spiked human saliva samples. Intraday and interday precision, expressed as relative standard deviation, was below 4.2 and 7.8% for cortisone and cortisol, respectively. The method was successfully applied to the determination of cortisone and cortisol in saliva from healthy volunteers (n = 9) in the morning and in the evening. The method is simple, faster, and more environmentally friendly than the current ones.

Carbon nanotubes magnetic hybrid nanocomposites for a rapid and selective preconcentration and clean-up of mercury species in water samples.

Hybrid nanocomposites based on Fe3O4 magnetic nanoparticles (MNPs) coated with different types of carbon nanotubes (CNTs) have been studied for the first time as sorbent materials for magnetic solid phase extraction (MSPE) for mercury speciation analysis. Monomethylmercury (MMHg) was the target mercury species in water samples and the adsorption and desorption processes were optimized based on this species. Single-walled CNT-MNP showed higher adsorption capacity than double-walled or multi-walled CNTs. Then, the magnetic sorbent was retrieved with an external magnet and MMHg was selectively desorbed from it with dichloromethane (DCM) in two steps with vortex agitation. Inorganic mercury was removed during the desorption stage. The rapid adsorption and desorption equilibrium, the magnetic separation of the sorbent, and the simple and fast synthesis of CNT-MNPs without any additional modification of the CNTs simplified and shortened the extraction procedure. The extract was submitted to derivatization of the mercury species by ethylation (with an optional nitrogen stream evaporation of the organic phase) and injection into a gas chromatograph coupled to an atomic fluorescence detector (GC-pyro-AFS). The overall procedure provides the preconcentration of MMHg up to 150 times and the removal of inorganic mercury at the same time. The procedural limits of detection (LOD) and quantification (LOQ) were 5.4 and 17.9pgmL-1, respectively. Moreover, magnetic nanocomposites can be reused at least 7 times without losing their efficiency. The methodology was validated in tap, dam and river water samples to evaluate the performance under real conditions with recoveries from 79% to 97% of spiked MMHg.

Magnetic nanoparticles-carbon nanotubes hybrid composites for selective solid-phase extraction of polycyclic aromatic hydrocarbons and determination by ultra-high performance liquid chromatography.

A rapid and reliable method based on magnetic solid-phase extraction (MSPE) and ultra-high performance liquid chromatography (UHPLC-FLD) analysis was developed and validated for the quantitative determination of seven polycyclic aromatic hydrocarbons (PAHs) in water samples. Hybrid composites made up of magnetic nanoparticles (MNPs) and carbon nanotubes (CNTs) were tested as adsorbent materials. The main factors influencing the extraction yields were optimized, namely the amount and type of adsorbent in the adsorption, and the solvent, the type of energy and the time in the desorption step. The selected composite was made up of Fe3O4 and multiwalled (MW)-CNTs. The desorption was carried out with sonication probe and tetrahydrofuran (THF); this solvent makes the method directly compatible with the chromatographic mobile phase and it reduces the analysis time. Under the optimized conditions, the LODs and LOQs achieved were in the range of 0.025-0.73 and 0.04-2.4 ng mL-1, respectively. The calibration curves were linear (R 2 ≥ 0.9936) over the concentration ranges from 1 to 500 ng mL-1. The recoveries of PAHs were from 76.4 ± 1.7 up to 106.5 ± 3.5%. The method was applied to synthetic and real (tap, dam, river and mineral) water samples with different characteristics to evaluate the performance under real conditions.

Mapping the spatio-temporal risk of lead exposure in apex species for more effective mitigation.

Effective mitigation of the risks posed by environmental contaminants for ecosystem integrity and human health requires knowing their sources and spatio-temporal distribution. We analysed the exposure to lead (Pb) in griffon vulture Gyps fulvus-an apex species valuable as biomonitoring sentinel. We determined vultures' lead exposure and its main sources by combining isotope signatures and modelling analyses of 691 bird blood samples collected over 5 years. We made yearlong spatially explicit predictions of the species risk of lead exposure. Our results highlight elevated lead exposure of griffon vultures (i.e. 44.9% of the studied population, approximately 15% of the European, showed lead blood levels more than 200 ng ml(-1)) partly owing to environmental lead (e.g. geological sources). These exposures to environmental lead of geological sources increased in those vultures exposed to point sources (e.g. lead-based ammunition). These spatial models and pollutant risk maps are powerful tools that identify areas of wildlife exposure to potentially harmful sources of lead that could affect ecosystem and human health.

Analysis of silica nanoparticles by capillary electrophoresis coupled to an evaporative light scattering detector.

A simple and rapid methodology has been developed to identify and separate silica nanoparticles (SiO2NPs) of different sizes in aqueous solution by capillary zone electrophoresis coupled to an evaporative light scattering detector (CE-ELSD). SiO2NPs were separated using 3 mM ammonium acetate buffer, containing 1% methanol at pH 6.9. SiO2NPs of 20, 50 and 100 nm were successfully separated under the optimum experimental conditions. CE coupled to ELSD has been proven to be an effective separation technique to determine particles with such small sizes, although the peaks are very close to each other, and it is a promising technique that may allow the separation of other types of nanoparticles. Confirmation by TEM and quantification of the SiO2 content was also carried out by inductively coupled plasma-mass spectrometry (ICP-MS). The new method was applied to the analysis of real samples, in order to assess its ability to avoid matrix effects in the determination of SiO2NPs in these kinds of samples.

Sources and fate of mercury pollution in Almadén mining district (Spain): Evidences from mercury isotopic compositions in sediments and lichens.

Variations in mercury (Hg) isotopic compositions have been scarcely investigated until now in the Almadén mining district (Spain), which is one of the most impacted Hg areas worldwide. In this work, we explore and compare Hg isotopic signatures in sediments and lichens from Almadén mining district and its surroundings in order to identify and trace Hg aquatic and atmospheric contamination sources. No statistically significant mass independent fractionation was observed in sediments, while negative Δ(201)Hg values from -0.12 to -0.21‰ (2SD = 0.06‰) were found in lichens. A large range of δ(202)Hg values were reported in sediments, from -1.86 ± 0.21‰ in La Serena Reservoir sites far away from the pollution sources to δ(202)Hg values close to zero in sediments directly influenced by Almadén mining district, whereas lichens presented δ(202)Hg values from -1.95 to -0.40‰ (2SD = 0.15‰). A dilution or mixing trend in Hg isotope signatures versus the distance to the mine was found in sediments along the Valdeazogues River-La Serena Reservoir system and in lichens. This suggests that Hg isotope fingerprints in these samples are providing a direct assessment of Hg inputs and exposure from the mining district, and potential information on diffuse atmospheric contamination and/or geochemical alteration processes in less contaminated sites over the entire hydrosystem. This study confirms the applicability of Hg isotope signatures in lichens and sediments as an effective and complementary tool for tracing aquatic and atmospheric Hg contamination sources and a better constraint of the spatial and temporal fate of Hg released by recent or ancient mining activities.

Mercury exposure and mechanism of response in large game using the Almadén mercury mining area (Spain) as a case study.

Mercury (Hg) accumulation, transfer, defense mechanism and adverse effects were studied in red deer (Cervus elaphus) and wild boar (Sus scrofa) from the Almadén mining district (Spain), the largest (285,000 t of Hg) and the oldest (more than 2000 years) Hg mine/refining operation site in the world. Red deer (n=168) and wild boar (n=58) liver, kidney, bones (metacarpus), testis and muscle were analyzed for total Hg and selenium (Se) within a range of distances to the Almadén mining district. The highest Hg concentrations were found in kidney (0.092 and 0.103 µg/g d.w. for red deer and wild boar, respectively) followed by the levels in liver (0.013 and 0.023 µg/g d.w. for red deer and wild boar, respectively). A significant correlation (r=-0.609, p=0.007) was found between Hg concentrations and distance to the Almadén Hg mining district. However, both red deer and wild boar closest to the mining area still showed mercury concentrations well below the concentration associated with clinical signs of Hg poisoning. Highest Se concentrations were found in kidney (2.60 and 6.08 µg/g in red deer and wild boar, respectively) and testis (2.20 µg/g in red deer). For selenium, differences between red deer and wild boar were statistically significant (p<0.05) in all tissues, concentrations being higher in wild boar than in red deer. In the diagnosis of Se deficiency, the vast majority of the examined red deer livers were deficient. A significant correlation was found between Hg and Se in kidney (r=0.386, p>0.001 for red deer and r=0.567, p=0.005 for wild boar). Liver GSSG concentrations were negatively correlated to total mercury and Hg:Se molar ratio in male deer, which could indicate a hormetic response to Hg exposure. Moreover, a positive association was found between the antioxidant element Se and antioxidant vitamins in red deer tissues.

Mercury speciation in the Valdeazogues River-La Serena Reservoir system: influence of Almadén (Spain) historic mining activities.

Mercury (Hg) speciation and partitioning have been investigated in a river-reservoir system impacted by the Almadén mining activities, the world's largest Hg district. This study is the first to simultaneously investigate Hg dynamics from above the mining district and into the La Serena Reservoir (3219 Hm(3)), being the third largest reservoir in Europe and the largest in Spain. Water, sediment and biota were sampled at different seasons during a 2-year study from the Valdeazogues River, which flows east-west from the mining District, to La Serena Reservoir. Simultaneously, a comprehensive study was undertaken to determine the influence of some major physico-chemical parameters that potentially influence the fate of Hg within the watershed. Concentrations of dissolved Hg in water were below 0.14 microg/L, whereas particulate Hg ranged from 0.1 to 87 microg/g, with significant seasonal variation. Total Hg concentrations varied from 7 to 74 microg/g in sediment from the Valdeazogues River, while in sediments from La Serena Reservoir were below 2 microg/g. On the other hand, methyl-Hg reached concentrations up to 0.3 ng/L in water and 6 ng/g in sediment from La Serena Reservoir, whereas maximum concentrations in Valdeazogues River were 5 ng/L and 880 ng/g in water and sediment, respectively. The distribution of Hg species in the Valdeazogues River-La Serena Reservoir system indicated a source of Hg from the mine waste distributed along the river. Total Hg in water was strongly correlated with total dissolved solids and chlorophyll a concentrations, whereas organic carbon and Fe concentrations seem to play a role in methylation of inorganic Hg in sediment. Total Hg concentrations were low in fish from Valdeazogues River (0.8-8.6 ng/g, wet weight) and bivalves from La Serena Reservoir (10-110 ng/g, wet weight), but most was present as methyl-Hg.