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1.
JAMA ; 323(1): 35-48, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-32207767

RESUMO

Importance: Dietary supplements marketed for male fertility commonly contain folic acid and zinc based on limited prior evidence for improving semen quality. However, no large-scale trial has examined the efficacy of this therapy for improving semen quality or live birth. Objective: To determine the effect of daily folic acid and zinc supplementation on semen quality and live birth. Design, Setting, and Participants: The Folic Acid and Zinc Supplementation Trial was a multicenter randomized clinical trial. Couples (n = 2370; men aged ≥18 years and women aged 18-45 years) planning infertility treatment were enrolled at 4 US reproductive endocrinology and infertility care study centers between June 2013 and December 2017. The last 6-month study visit for semen collection occurred during August 2018, with chart abstraction of live birth and pregnancy information completed during April 2019. Interventions: Men were block randomized by study center and planned infertility treatment (in vitro fertilization, other treatment at a study site, and other treatment at an outside clinic) to receive either 5 mg of folic acid and 30 mg of elemental zinc (n = 1185) or placebo (n = 1185) daily for 6 months. Main Outcomes and Measures: The co-primary outcomes were live birth (resulting from pregnancies occurring within 9 months of randomization) and semen quality parameters (sperm concentration, motility, morphology, volume, DNA fragmentation, and total motile sperm count) at 6 months after randomization. Results: Among 2370 men who were randomized (mean age, 33 years), 1773 (75%) attended the final 6-month study visit. Live birth outcomes were available for all couples, and 1629 men (69%) had semen available for analysis at 6 months after randomization. Live birth was not significantly different between treatment groups (404 [34%] in the folic acid and zinc group and 416 [35%] in the placebo group; risk difference, -0.9% [95% CI, -4.7% to 2.8%]). Most of the semen quality parameters (sperm concentration, motility, morphology, volume, and total motile sperm count) were not significantly different between treatment groups at 6 months after randomization. A statistically significant increase in DNA fragmentation was observed with folic acid and zinc supplementation (mean of 29.7% for percentage of DNA fragmentation in the folic acid and zinc group and 27.2% in the placebo group; mean difference, 2.4% [95% CI, 0.5% to 4.4%]). Gastrointestinal symptoms were more common with folic acid and zinc supplementation compared with placebo (abdominal discomfort or pain: 66 [6%] vs 40 [3%], respectively; nausea: 50 [4%] vs 24 [2%]; and vomiting: 32 [3%] vs 17 [1%]). Conclusions and Relevance: Among a general population of couples seeking infertility treatment, the use of folic acid and zinc supplementation by male partners, compared with placebo, did not significantly improve semen quality or couples' live birth rates. These findings do not support the use of folic acid and zinc supplementation by male partners in the treatment of infertility. Trial Registration: ClinicalTrials.gov Identifier: NCT01857310.


Assuntos
Ácido Fólico/administração & dosagem , Nascimento Vivo , Sêmen/efeitos dos fármacos , Oligoelementos/administração & dosagem , Complexo Vitamínico B/administração & dosagem , Zinco/administração & dosagem , Adulto , Fragmentação do DNA , Suplementos Nutricionais , Feminino , Fertilização In Vitro , Ácido Fólico/efeitos adversos , Humanos , Infertilidade/terapia , Infertilidade Masculina/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Gravidez , Análise do Sêmen , Fatores Socioeconômicos , Contagem de Espermatozoides , Motilidade Espermática , Oligoelementos/efeitos adversos , Resultado do Tratamento , Complexo Vitamínico B/efeitos adversos , Adulto Jovem , Zinco/efeitos adversos
2.
Environ Monit Assess ; 192(4): 246, 2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32206882

RESUMO

Clearwater Mesa is a pristine area located SE of Croft Bay in James Ross Island, at the northeast of the Antarctic Peninsula. The closest anthropic construction is the summer Mendel station located 25 km to the NE. Clearwater is a remote basalt volcanic mesa, (64° 01' S, 57° 42' W) located at ~ 250 m a.s.l., with around 50 small shallow lakes, a well-developed lichens flora and scarce fauna. The mesa offers a good opportunity to use lichens, like Usnea antarctica, as a biomonitor species. The aim of this study was to determine the baseline levels of trace elements in Usnea antarctica and their relationships with geographical parameters and climatological aspects, to use them as reference levels in futures studies. Usnea antarctica was collected in 23 sites in two transects: perpendicular and parallel to the shore. We found high contents of the elements associated with long-distance transport like Sm, La, Sc, Fe, Co, Hg, and Ca. The elements linked to the marine biogenic cycle as Sr, Rb, Cs, K, Na, Sb, As, Se, and Br were less significant. The distance to the sea was the factor that related the element contents. Hg, Se, As, and Br content in Usnea antarctica increased from the inland towards the sea coast.


Assuntos
Monitoramento Ambiental , Oligoelementos , Usnea , Regiões Antárticas , Oligoelementos/análise , Usnea/química
3.
Environ Monit Assess ; 192(4): 215, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32140832

RESUMO

In order to evaluate the level of atmospheric pollution in the north of Western Siberia, we studied the composition of urban snow in the vicinity of the Tazovsky settlement as well as in the area of Zapolyarnoye-the largest natural gas field in Russia in terms of a total extraction volume. Our results indicate that anthropogenic activities have caused an increase in electric conductivity and pH values of meltwaters. Concentrations of dissolved and particulate forms of trace elements (Fe, Mn, Ni, Cr, Cu, Pb, Zn, and Cd) were determined using atomic absorption spectroscopy. Dissolved forms of Cd, Zn, and Mn and particulate forms of Cu, Fe, and Ni prevailed in meltwaters of background territories. Human-affected territories were characterized by a predominance of particulate forms of trace elements (except Cd), which indicated increased dust deposition rates. For Cu, Mn, and Fe, mean values of contamination factor (CF) exceeded background levels by 4.4, 4.7, and 6.6 times, respectively. At some sampling sites, concentrations of trace elements exceeded background levels by 10-111 times. The concentration of Zn in our study area was higher than those in other oil and gas fields located in polar and boreal regions. The Cd concentration in the vicinity of the Tazovsky settlement was higher than those in other cities of Western Siberia. The data obtained in the present study on concentrations of soluble and particulate forms of trace elements in snow will be valuable for environmental protection in Russia's Arctic territory.


Assuntos
Monitoramento Ambiental , Neve , Oligoelementos , Cidades , Humanos , Federação Russa , Sibéria
4.
Waste Manag ; 105: 414-424, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32126369

RESUMO

The release of potentially toxic elements as airborne fine particulates is a significant environmental risk associated with recycling e-waste. Some of these may redeposit near emission sites or be transported over long distances causing wide-spread pollution. With an aim to identify key factors affecting particulate emissions, we report novel investigations on the adsorptive capture of particulate matter (PM) released during low temperature pyrolysis (600 °C; 15 min) of waste printed circuit boards (PCBs). A significant proportion of the released particulates (5.3 to 37%) were captured by adsorbents located downstream and in close proximity to the emitting source. Data was collected for four different PCBs and three adsorbents: alumina, silica-gel and activated carbon. With sizes ranging from nanoparticles to over 10 µm, adsorbed particulates were present as fines, spheres, oblongs, clusters and larger particles with no specific shape. Of the 24 elements identified initially in waste PCBs, only 14 were detected in released particulates: major PTEs- Zn, Sn, Pb and Cu (up to 400 ppm); minor PTEs- Ni, Mn, Cd, Cr and Ba (up to 10 ppm); trace PTEs- Co, In, Bi, Be and Sb (up to 1 ppm). Key factors influencing the release of PTEs during thermal processing were identified as basic elemental characteristics, densities, melting points, vapor pressures, initial concentrations, local bonding and mechanical strength. These results show that the presence of low melting point/high vapour pressure elements (Zn, Pb, Sn) should be minimised for a significant reduction in PTE emissions during e-waste processing.


Assuntos
Resíduo Eletrônico , Oligoelementos , Poeira , Monitoramento Ambiental , Material Particulado , Reciclagem
5.
Zhonghua Yu Fang Yi Xue Za Zhi ; 54(3): 289-293, 2020 Mar 06.
Artigo em Chinês | MEDLINE | ID: mdl-32187934

RESUMO

Objective: To understand the levels of Pb, Cd, As, Hg, Mn, and Se in maternal and umbilical cord blood, and to explore the transplacental transfer efficiency (TTE). Methods: From September 2010 to December 2013, a total of 773 pregnant women and their newborns (Laizhou Bay Birth Cohort) were recruited from a second grade hospital in the south bank of Laizhou Bay, Bohai, Shandong Province. According to different detection methods, the six measured elements are classified into three groups including the Hg measurement group (595 mother-newborn pairs), the Pb measurement group (534 mother-newborn pairs), and the Cd, As, Mn and Se measurement group (244 mother-newborn pairs). The demographic characteristics of pregnant women and their newborns were obtained by the questionnaire. The concentrations of elements in maternal and umbilical cord blood were detected and the TTE of each element (elemental concentration in cord blood/elemental concentration in maternal blood) was calculated. The correlation of elements between maternal and cord blood was analyzed using Spearman's rank correlation coefficient. Results: The mean±SD of maternal age, gestational week and newborn birth weight of 773 mother-infant pairs were (28.34±4.50) years, (39.47±1.39) weeks and (3 419.47±497.39) g respectively. The median concentrations of Pb, Cd, As, Hg, Mn and As in maternal and cord blood were 31.12 and 30.02, 1.19 and 0.47, 8.05 and 6.03, 0.69 and 1.26, 100.70 and 105.55, 127.25 and 115.00 µg/L, respectively. The TTE of Pb, Cd, As, Hg, Mn, and Se was 0.98, 0.41, 0.73, 1.73, 0.96 and 0.91, respectively. Pb, Cd, Hg, Mn, and Se showed a significant positive correlation between maternal blood and cord blood, with Spearman correlation coefficients of 0.397, 0.298, 0.698, 0.555, and 0.285 (all P values<0.001). Conclusion: Each element was commonly detected in maternal blood and cord blood. The TTE of Hg was the highest.


Assuntos
Cádmio/sangue , Sangue Fetal/química , Sangue Fetal/metabolismo , Chumbo/sangue , Manganês/sangue , Troca Materno-Fetal , Mercúrio/sangue , Selênio/sangue , Cordão Umbilical/química , Biomarcadores/análise , Biomarcadores/sangue , Feminino , Humanos , Recém-Nascido , Gravidez , Oligoelementos/análise , Oligoelementos/sangue , Cordão Umbilical/irrigação sanguínea
6.
Sci Total Environ ; 715: 136639, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32040989

RESUMO

Due to the utilization of landfill technology and geothermal energy production in Tibet, the contamination of the soils and underground water by trace element has currently become a serious problem, both ecologically and to the human health point of view. However, relevant studies concerning this critical problem, particularly in the Tibet area has not been found. Therefore, this study investigated the soil contamination and the spatial distribution of the trace elements in the areas surrounding the Tibetan landfill sites (LS) and geothermal sites (GS) through several pollution evaluation models. In addition, the possible sources of trace elements and their potential impact on public health were also investigated. Results showed that the trace elements in soils nearby LS and GS had moderate to high contamination risk. In soils surrounding LS, mercury had the highest concentration of 0.015 mg/kg and was 6 times higher than the background value of 0.008 mg/kg while in GS, arsenic had the highest concentration of 66.55 mg/kg, and exceeded the soil contamination risk value of 25 mg/kg. Maizhokunggar LS was the most polluted site with an average pollution load index value of 2.95 compared to Naqu, Nyingchi, Shigatse, and Lhasa. 42% of LS were with considerable ecological risk, and all GS had low ecological risk. Both carcinogenic and non-carcinogenic risk for children and adults (male, female) were within the acceptable range. According to the source analysis, unscientific anthropogenic activities including accumulated MSW, industrial discharges, and vehicle emissions significantly contributed 51.83% to soil trace element contamination. Considering that Tibet is an environment-ecologically vulnerable region with very weak self-adjustment ability, accumulated municipal solid waste in the landfill sites should be well disposed of, and even soil remediation should be well implemented.


Assuntos
Solo , Monitoramento Ambiental , Metais Pesados , Medição de Risco , Poluentes do Solo , Tibet , Oligoelementos , Instalações de Eliminação de Resíduos
7.
Anal Bioanal Chem ; 412(8): 1847-1861, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32020317

RESUMO

Biomonitoring for human exposure to lead, arsenic, mercury, and other toxic metal(loid)s often relies on analyzing traditional biospecimens such as blood and urine. While biomonitoring based on blood and urine is well-established, non-traditional biospecimens such as hair and nails can offer the potential to explore past exposures as well as the advantages of non-invasive collection and ease of storage. The present study describes the production of four reference materials (NYS RMs 18-01 through 18-04) based on caprine horn, a keratinized tissue similar to human hair and nails, intended to serve as a resource for calibration, quality control, and method validation purposes. The elemental content and homogeneity of these candidate reference materials were characterized for 17 elements using inductively coupled plasma mass spectrometry (ICP-MS). Commutability between two or more of the NYS caprine horn RMs and human nails was established for 8 elements (Ba, Ca, Cr, Cu, Mn, Pb, Sr, and Zn) based on analysis by ICP-MS/MS and ICP-optical emission spectrometry. The development and optimization of an ICP-MS/MS instrumental method for the determination of 17 elements in keratinized tissues is described. The method was validated against three certified reference materials based on human hair showing good accuracy and method repeatability better than 25% for all analytes. This study also describes sample preparation issues and addresses common challenges including surface contamination, microwave digestion, matrix effects, and spectral interferences in inorganic mass spectrometry. New York State Department of Health Keratin Matrix Reference Materials. Graphical abstract.


Assuntos
Queratinas/química , Oligoelementos/análise , Animais , Calibragem , Cabras , Cabelo/química , Humanos , Limite de Detecção , Unhas/química , Padrões de Referência , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos , Oligoelementos/normas
8.
Mar Pollut Bull ; 151: 110820, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056613

RESUMO

This study evaluates the geographical distribution of Pb, Cd, Cr, Ni, Co, Cu, Zn, Mn and Fe in wild mussels Mytilus galloprovincialis as well as in associated suspended particulate matter (SPM) and sediments from the Algerian coast. The bioaccumulation (metal concentrations in tissue), bioavailability (metal indices) and bioconcentration of trace metals from the adjacent environment were assessed. The computed pollution load index (PLI) indicates that the sediments are not polluted by these metals, except for Zn which shows a moderate level of contamination. All the metals in SPM samples are in a 'safe range' with respect to the computed degree of contamination (DC < 2). The target hazard quotients (THQ) and the hazard index (HI) values indicate a risk level with Fe. However, the Cr measured in mussels is considered 'extreme', according to the consumption rate limit for mussels (CRlim) which limits their consumption to 0.5 kg/day.


Assuntos
Exposição Dietética/estatística & dados numéricos , Monitoramento Ambiental , Metais/análise , Poluentes Químicos da Água/análise , Animais , Bivalves , Ecossistema , Humanos , Metais Pesados , Medição de Risco , Oligoelementos , Poluição Química da Água/estatística & dados numéricos
9.
Mar Pollut Bull ; 151: 110876, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056652

RESUMO

Mobile marine predators, such as seabirds, are frequently used as broad samplers of contaminants that are widespread in the marine environment. The Timor Sea off remote Western Australia is a poorly studied, yet rapidly expanding area of offshore development. To provide much needed data on contamination in this region, we quantified trace element concentrations in breast feathers of three seabird species breeding on Bedout Island. While adult Masked Boobies Sula dactylatra exhibited some of the highest concentrations, values for all species were below toxicology thresholds for seabirds and were comparable to those reported in other closely related species. The low concentrations detected in the birds provide a valuable baseline and suggest that the local marine environment around Bedout is in relatively good condition. However, careful monitoring is warranted in light increasing anthropogenic activity in this region.


Assuntos
Aves , Monitoramento Ambiental , Plumas , Oligoelementos , Animais , Cruzamento , Indonésia , Ilhas , Austrália Ocidental
10.
Mar Pollut Bull ; 151: 110878, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056654

RESUMO

We determined levels of mercury, cadmium, lead and selenium in muscle and liver of 29 specimens of a large pelagic fish rarely investigated, the Mediterranean spearfish Tetrapturus belone (Raf., 1810). The following element concentration ranking (mean ± S.D.; espressed in mg/kg dry weight) was recorded in muscle: Hg (3.401 ± 1.908) > Se (1.727 ± 0.232) > Pb (0.532 ± 0.322) > Cd (0.019 ± 0.015), and Se (6.577 ± 1.789) > Cd (5.815 ± 3.038) > Hg (2.698 ± 2.214) > Pb (0.661 ± 1.334) in liver. Levels of Hg, Se and Cd were compared to those reported for other Istiophoridae from oceanic areas and for other large predators of Mediterranean Sea, like swordfish and tuna. Organotropism of trace elements and their relation to size was discussed. Ecophysiological considerations regarding the Se-Hg relationship as well as Se-Cd indicate a possible detoxification mechanism. The implications for human consumption are briefly discussed.


Assuntos
Monitoramento Ambiental , Peixes , Oligoelementos , Poluentes Químicos da Água , Animais , Humanos , Fígado , Mar Mediterrâneo , Mercúrio , Selênio
12.
J Med Virol ; 92(5): 479-490, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32052466

RESUMO

An outbreak of a novel coronavirus (COVID-19 or 2019-CoV) infection has posed significant threats to international health and the economy. In the absence of treatment for this virus, there is an urgent need to find alternative methods to control the spread of disease. Here, we have conducted an online search for all treatment options related to coronavirus infections as well as some RNA-virus infection and we have found that general treatments, coronavirus-specific treatments, and antiviral treatments should be useful in fighting COVID-19. We suggest that the nutritional status of each infected patient should be evaluated before the administration of general treatments and the current children's RNA-virus vaccines including influenza vaccine should be immunized for uninfected people and health care workers. In addition, convalescent plasma should be given to COVID-19 patients if it is available. In conclusion, we suggest that all the potential interventions be implemented to control the emerging COVID-19 if the infection is uncontrollable.


Assuntos
Antivirais/uso terapêutico , Infecções por Coronavirus/terapia , Imunização Passiva , Estado Nutricional , Pneumonia Viral/terapia , Betacoronavirus/patogenicidade , China , Humanos , Fatores Imunológicos/uso terapêutico , Plasma , Oligoelementos/uso terapêutico , Vacinas Virais/administração & dosagem , Vitaminas/uso terapêutico
13.
Water Res ; 172: 115522, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32006774

RESUMO

Selenium (Se) and zinc (Zn) are essential micronutrients that are often lacking in the diet of humans and animals, leading to deficiency diseases. Lemna and Azolla are two aquatic plants with a substantial protein content, which offer the possibility of utilizing them to remove Se and Zn from (waste)water while producing micronutrient-enriched dietary proteins and fertilizers. In this study, we explored interaction effects occurring between Se and Zn when these micronutrients are taken up by Azolla and Lemna. The two aquatic plants were grown on hydroponic cultures containing 0-5.0 mg/L of Se (Se(IV) or Se(VI)) and Zn. The Se and Zn content of the plants, growth indicators, bioconcentration factor (BCF) and Se/Zn removal efficiency from the water phase were evaluated. The results demonstrated that Se(IV) is more toxic than Se(VI) for both plant species, as evidenced by the remarkable decrease of biomass content and root length when exposed to Se(IV). Both aquatic plants took up around 10 times more Se(IV) than Se(VI) from the medium. Moreover, the Se accumulation and removal efficiency increased by 66-99% for Se(IV) and by 34-59% for Se(VI) in Lemna when increasing Zn dosage from 0 to 5.0 mg/L in the medium, whereas it declined by 13-26% for Se(IV) and 21-35% for Se(VI) in Azolla, suggesting a synergetic effect in Lemna, but an antagonistic effect in Azolla. The maximum BCF of Se in Lemna and Azolla were 507 and 667, respectively. The protein content in freeze-dried Lemna and Azolla was approximately 17%. The high tolerance and accumulation of Se and Zn in Lemna and Azolla, combined with their rapid growth, high protein content and transformation of inorganic to organic Se species upon Se(IV) exposure make Lemna and Azolla potential candidates for the production of Se(IV)- and Zn-enriched biomass that can be used as crop fertilizers or protein-rich food/feed supplements or ingredients. Accordingly, by growing the Azolla and Lemna on wastewater, a high-value product can be produced from wastewater while recovering resources.


Assuntos
Araceae , Selênio , Oligoelementos , Animais , Humanos , Micronutrientes , Zinco
14.
J Environ Manage ; 260: 110063, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32090810

RESUMO

Bacteria isolated from soils in the vicinity of phosphogypsum (PG) stockpiles were studied for their potential use in bioaugmentation-assisted phytoextraction. Quick, miniaturized biochemical tests were performed in the presence of metal trace elements (MTE), including rare earth elements (Cd, Sr, Ce, La, Nd and Y), corresponding to their bioavailable concentrations in PG. The intention herein was to assess the capacity of bacteria to: i) grow in PG; ii) produce indole acetic acid and ACC deaminase to promote plant growth and reduce stress; and iii) produce siderophores, including pyoverdine, to mobilize MTE. Results showed that even at maximum PG concentration (10 g/L and pH 3.40), 7 out of 32 isolates were able to grow. The biochemical tests showed differences in the presence or absence of MTE. The presence of MTE seems to promote the production of IAA by a factor of 3.25. On the contrary, it inhibits ACC deaminase and siderophore production, including pyoverdine. According to a scoring method applied, the two most efficient isolates exhibiting maximum metabolite production were identified as Bacillus sp.


Assuntos
Poluentes do Solo , Oligoelementos , Bactérias , Biodegradação Ambiental , Sulfato de Cálcio , Ácidos Indolacéticos , Fósforo , Raízes de Plantas , Sideróforos , Solo , Microbiologia do Solo
15.
Environ Monit Assess ; 192(3): 174, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32052191

RESUMO

Association of trace metal concentrations in water is problematic; however, its information is scarce and sometimes contradicted. This work presents variations in dissolved major constituents and trace element concentrations along the quaternary aquifers located in middle Upper Egypt (Minia and Assiut governorates). A total of 205 groundwater samples from these aquifers were collected. Auxiliary parameters (pH, alkalinity, and conductivity), major cations (Ca2+, Mg2+, Na+, and K+), dominant anions (HCO3-, SO42-, Cl-, and NO3-), and trace element (B, Fe, Cu, Mn, Ni, Pb, Cd, and Cr) concentrations were measured in all samples. Univariate (correlation coefficient and scatter matrix) analysis was employed combined with multivariate (principal coordinates analysis) analysis to identify the chemical characteristics of groundwater that are responsible for generating most of the variability within the dataset. Also, hierarchical cluster analysis was applied to classify the geochemical origin of the groundwater constituents. The results indicate that the groundwater pollution is mainly due to water-rock interactions, including aquifer matrix dissolution, redox reaction of trace metals, input from wastewater, and agricultural fertilizers.


Assuntos
Água Subterrânea , Oligoelementos , Poluentes Químicos da Água , Egito , Monitoramento Ambiental
16.
Mar Pollut Bull ; 150: 110779, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31910526

RESUMO

This study was concerned with spatial analysis of mercury (Hg) in sediment samples of the USA coastal areas using more accurate and stable hybrid approaches compared to the conventional methods. An ensemble of simulated annealing along with least angle regression (SA-LAR) was applied for selection of predictors in spatial analysis. The latest algorithm was efficient with resultant RMSE and R2 of 0.066 and 0.705 compared to 0.099 and 0.571 for the traditional method of recursive feature elimination (RFE) approach. Using Cu, Pb and As as selected variables, it was tried to improve the spatial forecasting of Hg with either a hybrid of generalized boosted regression and ordinary kriging (GBROK) or inverse distance weighting (GBRIDW). According to the results, the variance explained by cross validation (VECV) was improved from 7.52% and 9.76% for IDW and OK to 40.41% and 41.94% for the GBRIDW and GBROK methods, respectively.


Assuntos
Monitoramento Ambiental/métodos , Mercúrio , Oligoelementos , Poluição da Água/estatística & dados numéricos , Análise de Regressão , Análise Espacial
17.
Food Chem ; 313: 126094, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31923867

RESUMO

Element contents in different types of spices and aromatic herbs collected from Italy and Tunisia were evaluated. The aim was to evaluate: the possible differences and/or similarities among the analyzed samples; if it is possible related the samples to their geographical origins; the nutritional quality and the potential health risks. Potassium, Ca, Mg and Ni were low in laurel and rosemary; mint and thyme showed the highest Na and the lowest Se contents; arsenic and Cd levels were found highest in verbena which had also the lowest Hg content; lastly, black pepper had the highest Mn and the lowest Pb contents. Instead discrimination between Italian and Tunisian samples for each spices and aromatic herbs under analysis was achieved by PCA. Essential elements intake through samples was small. Levels of Pb in some samples exceed the maximum allowable level, but any safety risk for consumers is excluded.


Assuntos
Espectrometria de Massas , Especiarias/análise , Oligoelementos/análise , Análise Multivariada , Análise de Componente Principal , Rosmarinus/química , Rosmarinus/metabolismo , Sicília , Thymus (Planta)/química , Thymus (Planta)/metabolismo , Tunísia , Verbena/química , Verbena/metabolismo
18.
J Agric Food Chem ; 68(5): 1213-1225, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31903748

RESUMO

Organically farmed rice is believed to be healthier, safer, and eco-friendlier than its conventionally farmed counterparts and sells for a premium price in global markets. Deliberate mislabeling of organic rice has become a critical consumer concern in China and elsewhere, and there is an increased risk of buying fraudulent organic rice in the market place. In this study, stable isotopic and multielemental analysis combined with chemometrics was used to differentiate organically farmed rice from green and conventional rice in a 4-year experimental field trial from 2014 to 2017. A total of 108 rice samples and their associated soils were collected during the study from three farming (fertilization) systems to investigate whether there are long-term changes in the rice farming classification accuracy from climate effects. Stable carbon and nitrogen isotopic ratios (i.e., δ13C and δ15N) and 27 elemental contents (e.g., Na, K, Ca, Fe, and Zn) of rice and soil samples were determined and then evaluated using statistical analysis [i.e., one-way analysis of variance, multivariable correlation analysis, and modeling of partial least-squares discriminant analysis]. Although δ15N values can be an effective indicator for organic rice authentication during one crop rotation, both δ13C and δ15N values of rice were easily affected by rice cultivar and interannual soil fertilization and localized agroclimatic variations. These two isotopes were not able to separate organic rice from green and conventional rice accurately. Elemental contents of green and conventional rice (especially K and Ca) were found at higher levels due to the abundant application of synthetic fertilizers (e.g., KNO3, KH2PO4, and CaHPO4), unlike organically farmed rice, which primarily used animal manure and composts. Partial least-squares discriminant analysis modeling combined isotopic and elemental signatures to correctly differentiate organic rice from green and conventional counterparts, with an accuracy up to 100% over the 4-year study. Therefore, this multi-isotope and -element strategy proposes a more rigorous, alternative tool to combat fraudulent mislabeling of organic rice, increasing the trust of organically labeled rice products and supporting the integrity of the organic sector worldwide.


Assuntos
Isótopos de Carbono/análise , Contaminação de Alimentos/análise , Alimentos Orgânicos/análise , Isótopos de Nitrogênio/análise , Oryza/química , Oligoelementos/análise , China , Análise Discriminante , Fertilizantes/análise , Oryza/classificação , Solo/química
19.
Chemosphere ; 242: 125252, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896206

RESUMO

Phytostabilization aided by soil amendments has been advocated in areas contaminated by trace metals. In this study, the effects of indigenous weed (Setaria pumila), energy plant (Pennisetum sinese), cadmium (Cd)-hyperaccumulator (Sedum plumbizincicola), and copper (Cu)-tolerant plant (Elsholtzia splendens) on the bioavailability and mobility of Cu and Cd in polluted soil were evaluated after phytostabilization aided by limestone (0.1% wt) over four years. The four plants combined with limestone significantly increased soil pH and decreased Cu and Cd fractions extracted by NH4OAc and diffusive gradients in thin films (DGT) than the untreated soils, respectively. P. sinese treatments decreased DGT-extractable Cu and Cd by 52.1% and 40.5% than S. pumila treatments, respectively. S. plumbizincicola and E. splendens treatments increased acid-soluble fraction of Cu and decreased residual fraction of Cu compared with S. pumila treatments. P. sinese treatments had the lowest phytotoxicity (inhibitoryrates, superoxide dismutase, peroxidase and catalase activities) among all treatments. Moreover, EDTA kinetic extraction showed that S. plumbizincicola and E. splendens treatments increased the mobility of Cu and Cd by increasing labile and less labile fractions of Cu and Cd compared with P. sinese treatments. Present results suggest that P. sinese is recommended as the remediation plant for phytoremediation aided by amendments.


Assuntos
Biodegradação Ambiental , Cádmio/análise , Cobre/análise , Poluentes do Solo/análise , Ácidos , Disponibilidade Biológica , Carbonato de Cálcio , Plantas , Sedum , Solo , Oligoelementos
20.
Nat Commun ; 11(1): 556, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992707

RESUMO

Rivers are a major supplier of particulate and dissolved material to the ocean, but their role as sources of bio-essential dissolved iron (dFe) is thought to be limited due to rapid, efficient Fe removal during estuarine mixing. Here, we use trace element and radium isotope data to show that the influence of the Congo River margin on surface Fe concentrations is evident over 1000 km from the Congo outflow. Due to an unusual combination of high Fe input into the Congo-shelf-zone and rapid lateral transport, the Congo plume constitutes an exceptionally large offshore dFe flux of 6.8 ± 2.3 × 108 mol year-1. This corresponds to 40 ± 15% of atmospheric dFe input into the South Atlantic Ocean and makes a higher contribution to offshore Fe availability than any other river globally. The Congo River therefore contributes significantly to relieving Fe limitation of phytoplankton growth across much of the South Atlantic.


Assuntos
Compostos de Ferro/análise , Ferro/análise , Rios/química , Água do Mar/química , Oceano Atlântico , Congo , Monitoramento Ambiental , Sedimentos Geológicos/química , Oceanos e Mares , Fitoplâncton/metabolismo , Radioisótopos/análise , Rádio (Elemento)/análise , Oligoelementos , Poluentes Químicos da Água/análise
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