RESUMEN
Cacao from South America is especially used to produce premium quality chocolate. Although the European Food Safety Authority has not established a limit for cadmium (Cd) in chocolate raw material, recent studies demonstrate that Cd concentrations in cacao beans can reach levels higher than the legal limits for dark chocolate (0.8 mg kg-1, effective January 1st, 2019). Despite the fact that the presence of Cd in agricultural soils is related to contamination by fertilizers, other potential sources must be considered in Ecuador. This field study was conducted to investigate Cd content in soils and cacao cultivated on Ecuadorian farms in areas impacted by oil activities. Soils, cacao leaves, and pod husks were collected from 31 farms in the northern Amazon and Pacific coastal regions exposed to oil production and refining and compared to two control areas. Human gastric bioaccessibility was determined in raw cacao beans and cacao liquor samples in order to assess potential health risks involved. Our results show that topsoils (0-20 cm) have higher Cd concentrations than deeper layers, exceeding the Ecuadorian legislation limit in 39% of the sampling sites. Cacao leaves accumulate more Cd than pod husks or beans but, nevertheless, 50% of the sampled beans have Cd contents above 0.8 mg kg-1. Root-to-cacao transfer seems to be the main pathway of Cd uptake, which is not only regulated by physico-chemical soil properties but also agricultural practices. Additionally, natural Cd enrichment by volcanic inputs must not be neglected. Finally, Cd in cacao trees cannot be considered as a tracer of oil activities. Assuming that total Cd content and its bioaccessible fraction (up to 90%) in cacao beans and liquor is directly linked to those in chocolate, the health risk associated with Cd exposure varies from low to moderate.
Asunto(s)
Cacao/química , Cadmio/análisis , Exposición a Riesgos Ambientales/análisis , Contaminantes del Suelo/análisis , Agricultura , Cadmio/metabolismo , Ecuador , Exposición a Riesgos Ambientales/estadística & datos numéricos , Fertilizantes , Humanos , Suelo/química , Contaminantes del Suelo/metabolismo , América del SurRESUMEN
Due to its high adaptability, cassava (Manihot esculenta Crantz) is one of the world's most cultivated and consumed plants after maize and rice. However, there are relatively few scientific studies on this important crop. The objective of this review was therefore to summarize and discuss the available information on cassava cropping in order to promote sustainable practices in terms of production and consumption. Cassava cultivation has been expanding recently at the global scale and is widely consumed in most regions of South America, Africa, and Asia. However, it is also characterized by the presence in its roots of potentially toxic hydrocyanic acid. Furthermore, cassava can also absorb pollutants as it is currently cultivated near roads or factories and generally without consideration for potential sources of soil, water, or atmospheric pollution. Careful washing, peeling, and adequate preparation before eating are therefore crucial steps for reducing human exposure to both environmental pollutants and natural hydrocyanic acid. At present, there is not enough precise data available on this staple food crop. To improve our knowledge on the nutritive benefits versus health risks associated with cassava consumption, further research is necessary to compare cassava cultivars and precisely study the influence of preparation methods.
Asunto(s)
Producción de Cultivos , Contaminantes Ambientales , Manihot , Contaminación de Alimentos , Humanos , Raíces de Plantas , Riesgo , VerdurasRESUMEN
Borage, white mustard and phacelia, green manure plants currently used in agriculture to improve soil properties were cultivated for 10 wk on various polluted soils with metal(loid) concentrations representative of urban brownfields or polluted kitchen gardens. Metal(loid) bioavailability and ecotoxicity were measured in relation to soil characteristics before and after treatment. All the plants efficiently grow on the various polluted soils. But borage and mustard only are able to modify the soil characteristics and metal(loid) impact: soil respiration increased while ecotoxicity, bioaccessible lead and total metal(loid) quantities in soils can be decreased respectively by phytostabilization and phytoextraction mechanisms. These two plants could therefore be used for urban polluted soil refunctionalization. However, plant efficiency to improve soil quality strongly depends on soil characteristics.
Asunto(s)
Restauración y Remediación Ambiental/métodos , Metaloides/análisis , Metales/análisis , Contaminantes del Suelo/análisis , Biodegradación Ambiental , Humanos , Estiércol , Medición de Riesgo , Suelo/químicaRESUMEN
In the context of peri-urban atmospheric pollution by industrial lead recycling emissions, metal can transfer to plant shoots. Home gardeners consuming their produce can therefore be exposed to metal pollution. The Human Health Risk Assessment Protocol (HHRAP) model from the United States Environmental Protection Agency (US EPA) classically used in risk assessment provides foliar metal uptake predictions for large farms but is not adapted to cultures in kitchen gardens. Thus, this study developed a new model, entitled "DECA", which includes individually measured parameters and the washing of vegetables before human consumption. Results given by DECA and HHRAP models were compared with experimental measurements of lettuce. The data calculated by the DECA model were highly correlated with the measured values; the HHRAP model overestimates foliar lead uptake. Moreover, strong influences of factor of washing and time-dependent variations of loss coefficient were highlighted. Finally, the DECA model provided important risk assessment data regarding consumption of vegetables from kitchen gardens.
Asunto(s)
Contaminantes Atmosféricos/metabolismo , Lactuca/metabolismo , Plomo/metabolismo , Hojas de la Planta/metabolismo , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Plomo/análisis , Material Particulado/análisis , Material Particulado/metabolismoRESUMEN
Fine and ultrafine metallic particulate matters (PMs) are emitted from metallurgic activities in peri-urban zones into the atmosphere and can be deposited in terrestrial ecosystems. The foliar transfer of metals and metalloids and their fate in plant leaves remain unclear, although this way of penetration may be a major contributor to the transfer of metals into plants. This study focused on the foliar uptake of various metals and metalloids from enriched PM (Cu, Zn, Cd, Sn, Sb, As, and especially lead (Pb)) resulting from the emissions of a battery-recycling factory. Metal and metalloid foliar uptake by various vegetable species, exhibiting different morphologies, use (food or fodder) and life-cycle (lettuce, parsley and rye-grass) were studied. The mechanisms involved in foliar metal transfer from atmospheric particulate matter fallout, using lead (Pb) as a model element was also investigated. Several complementary techniques (micro-X-ray fluorescence, scanning electron microscopy coupled with energy dispersive X-ray microanalysis and time-of-flight secondary ion mass spectrometry) were used to investigate the localization and the speciation of lead in their edible parts, i.e. leaves. The results showed lead-enriched PM on the surface of plant leaves. Biogeochemical transformations occurred on the leaf surfaces with the formation of lead secondary species (PbCO(3) and organic Pb). Some compounds were internalized in their primary form (PbSO(4)) underneath an organic layer. Internalization through the cuticle or penetration through stomata openings are proposed as two major mechanisms involved in foliar uptake of particulate matter.
Asunto(s)
Contaminantes Atmosféricos/metabolismo , Lactuca/metabolismo , Lolium/metabolismo , Petroselinum/metabolismo , Hojas de la Planta/metabolismo , Microanálisis por Sonda Electrónica , Monitoreo del Ambiente , Fluorescencia , Plomo/metabolismo , Metaloides/metabolismo , Metales/metabolismo , Microscopía Electrónica de Rastreo , Material Particulado/análisis , Reciclaje , Espectrometría de Masa de Ion SecundarioRESUMEN
Ultrafine particulate matters enriched with metals are emitted into the atmosphere by industrial activities and can impact terrestrial and aquatic ecosystems. Thus, this study investigated the environmental effects of process particles from a lead-recycling facility after atmospheric deposition on soils and potential run-off to surface waters. The toxicity of lead-enriched PM for ecosystems was investigated on lettuce and bacteria by (i) germination tests, growth assays, lead transfer to plant tissues determination and (ii) Microtox analysis. The influence of ageing and soil properties on metal transfer and ecotoxicity was studied using three different soils and comparing various aged, spiked or historically long-term polluted soils. Finally, lead availability was assessed by 0.01 M CaCl(2) soil extraction. The results showed that process PM have a toxic effect on lettuce seedling growth and on Vibrio fischeri metabolism. Soil-PM interactions significantly influence PM ecotoxicity and bioavailability; the effect is complex and depends on the duration of ageing. Solubilisation or stabilisation processes with metal speciation changes could be involved. Finally, Microtox and phytotoxicity tests are sensitive and complementary tools for studying process PM ecotoxicity.
Asunto(s)
Contaminantes Atmosféricos/toxicidad , Residuos Industriales , Plomo/toxicidad , Material Particulado/toxicidad , Contaminantes del Suelo/toxicidad , Suelo , Contaminantes Atmosféricos/farmacocinética , Aliivibrio fischeri/efectos de los fármacos , Disponibilidad Biológica , Germinación , Residuos Industriales/análisis , Plomo/farmacocinética , Lactuca/efectos de los fármacos , Lactuca/crecimiento & desarrollo , Contaminantes del Suelo/farmacocinética , Factores de Tiempo , Pruebas de ToxicidadRESUMEN
We have enhanced magnetoresistance (MR) for current-perpendicular-to-plane giant-magnetoresistive (CPP-GMR) films with a current-confined-path nano-oxide layer (CCP-NOL). In order to realize higher purity in Cu for CCPs, hydrogen ion treatment (HIT) was applied as the CuO(x) reduction process. By applying the HIT process, an MR ratio was increased to 27.4% even in the case of using conventional FeCo magnetic layer, from 13.0% for a reference without the HIT process. Atom probe tomography data confirmed oxygen reduction by the HIT process in the CCP-NOL. The relationship between oxygen counts and MR ratio indicates that further oxygen reduction would realize an MR ratio greater than 50%.
RESUMEN
Toxicity and biotransformation of several earthworm contaminants are widely evaluated nowadays using biochemical biomarkers. Many investigations track enzyme activities as biomarkers of neurotoxicity (cholinesterase (ChE)), metabolisation (glutathione-S-transferase (GST)) and oxidative stress (catalase (CAT)). This study proposes an evaluation of the use of a combined buffer, to extract proteins from earthworms and then analyse the 3 biomarkers. The method provides good results and allows protein extraction and quantitative determination of biomarkers with the same efficiency as the enzyme-specific buffers. It decreases preparation time and permits a study of the biomarkers on the same individual with only one homogenisation.
Asunto(s)
Catalasa/aislamiento & purificación , Colinesterasas/aislamiento & purificación , Glutatión Transferasa/aislamiento & purificación , Oligoquetos/enzimología , Animales , Biomarcadores/análisis , Tampones (Química) , Cinética , Oligoquetos/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Extractos de Tejidos/químicaRESUMEN
A rapid and simultaneous method for residue identification and quantification for seven pesticides in agricultural soils has been developed to study a realistic situation in vineyard. The target compounds are two insecticides, two herbicides and three fungicides, from different chemical families. The procedure is based on a pressurized liquid extraction (PLE) with acetone, before a multiresidue GC-MS analysis. The recovery of PLE is between 53.8+/-2.4 and 99.9+/-4.4% according to pesticide. A limit of detection (LOD) between 1.4 and 4.6 microg kg(-1) of dry soil was obtained for five analytes. This procedure for testing soil contamination is sensitive and easy to perform.
Asunto(s)
Cromatografía de Gases y Espectrometría de Masas/métodos , Plaguicidas/análisis , Contaminantes del Suelo/análisis , Suelo/análisis , Vitis , Calibración , Iones/química , Plaguicidas/química , Contaminantes del Suelo/química , Temperatura , Factores de TiempoRESUMEN
The effects of a mixture of insecticides and/or fungicides at different environmental concentrations were investigated on a Aporrectodea caliginosa nocturna population. This laboratory experiment was carried out in order to reproduce Gaillac (France) vineyard conditions. Neurotoxicity (cholinesterase), metabolisation (glutathione-S-transferase) and oxidative stress (catalase) enzymes were studied as biomarkers in earthworms after short-term exposure in terraria. The aim was to observe the global effects of pesticide exposure, as in a vineyard, rather than focus on each isolated biomarker variation, or on each compound's impact. ChE activity was inhibited after a few days of insecticide and/or fungicide exposure, indicative of a neurotoxic effect in earthworms. The significant increase in GST and CAT activities revealed the metabolisation of these products resulting in the production of reactive oxygen species. After a long period of exposure or high concentrations, earthworms were physiologically damaged: they could not cope with the high toxicity (cellular dysfunction, protein catabolism...). Chemical analysis showed that pesticide bioaccumulation in earthworm tissues, even in those exposed to the highest concentrations and for the longest periods, was very low (under LOD) or absent. However, the study of pesticide residues in terraria after 34 days in a climate chamber suggested that earthworms participate in soil pesticide breakdown.
Asunto(s)
Fungicidas Industriales/toxicidad , Insecticidas/toxicidad , Oligoquetos/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Animales , Biomarcadores , Catalasa/metabolismo , Colinesterasas/metabolismo , Glutatión Transferasa/metabolismo , Oligoquetos/metabolismo , Proteínas/metabolismoRESUMEN
Since 1952 138 eyes with "retinochoroiditis juxtapapillaris" as described by Jensen, and directly comparable changes have been examined with subtile differentiating methods. Section I describes, in 78 eyes, the immediately recognizable, manifest forms; Section II, in 60 eyes, the masked forms concealed either initially or permanently by other phenomena in the fundus. In both groups there were patients in whom the juxtapapillary inflammatory focus appeared alone (solitary forms, 87 eyes) or associated with further typical plaques of new or old, disseminated or circumscribed, paracentral, equatorial, or peripheral choroiditis (combined forms, 51 eyes). Of the 78 eyes with manifest solitary or combined juxtapapillary choroiditis, 35 had a complete and irreversible sector-shaped or arcuate visual field defect as described by Jensen. However, a further 35 eyes clearly deviated from this: in 11 the sector-shaped or arcuate defect was complete and reversible, in 6 it was incomplete and irreversible, and in 3 it was incomplete and reversible. In 15 eyes with an apparently identical inflammatory focus there was merely an enlargement of Mariotte's blind spot commensurate with it in localization, configuration, and extent. Particularly noteworthy were 8 eyes in which a peripheral focus had caused the complete and irreversible sector-shaped visual field defect which Jensen considered exclusively characteristic of the juxtapapillaries described by him. Taken overall, the present author's investigations led to the fundamental finding that every inflammatory focus originating in the choroid, localized in any part of the fundus (juxtapapillary, paracentral, equatorial, or peripheral), can cause a scotoma corresponding to the focus to develop into an incomplete to complete, reversible to irreversible sector-shaped or arcuate defect in the visual field.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Coriorretinitis/diagnóstico , Coriorretinitis/patología , Coroides/patología , Diagnóstico Diferencial , Angiografía con Fluoresceína , Humanos , Disco Óptico/patología , Retina/patología , Campos VisualesRESUMEN
19 Following the inoculation of tissue culture cells with material obtained from 3 human eyes suffering from sympathetic ophthalmia (2 sympathizing = sy-l, 1 sympathized = sy-2), no growth of bacteria was observed. On the other hand, changes occurred such as are typical for a massive infection with mycoplasmas. The morphology of these microbes corresponds, down to the details, with micro-organisms which the author has frequently demonstrated and illustrated since 1948 in human, chicken and monkey eyes suffering from sympathetic ophthalmia. 2. With the cultures of mycoplasmas obtained from the eyes of human patients suffering from sympathetic ophthalmia, it was possible to produce the same symptoms in chickens as were described by the author in 1950 in sympathizing and sympathized human eyes, namely: torpid uveitis and papillitis, which dragged on for months, and affected not only the inoculated right eye, but also, after 3 weeks and more, the untouched left eye. 3. Identical phenomena involving both eyes have been observed in chickens, the right eyes of which were inoculated with a strain of mycoplasma hominis orale 1 cultivated from other material in the Institut für medizinische Mikrobiologie der Universität Mainz (Prof. Bredt) and given to the author. A chronic intraocular inflammation, which persisted for several months--up to 6 months and more--developed not only in the inoculated right eye of the animals, but also, after an interval of several weeks, in the untouched left eye. 4. Viewed critically and with due care, these findings suggest that mycoplasmas might well play a role in triggering off sympathetic ophthalmia. 5. The results reported on here indicate that intraocular inoculation with mycoplasmas is of importance both in microbiology and in general medicine.