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Bioécologie

Articles avec #radionucleides - chimiques - nanoparticules...

Report: The Fukushima Nuclear Accident Independent Investigation Commission

11 Mars 2017,

Publié par Bioécologie

National Diet of Japan Fukushima Nuclear Accident Independent Investigation Commission is the commission to investigate the background and cause of Fukushima Daiichi nuclear disaster.

The Fukushima nuclear accident "cannot be regarded as a natural disaster," the NAIIC panel's chairman, Tokyo University professor emeritus Kiyoshi Kurosawa, wrote in the inquiry report. "It was a profoundly man-made disaster -- that could and should have been foreseen and prevented. And its effects could have been mitigated by a more effective human response."

Read the report here

Fukushima prefecture, Japan, 2012
Fukushima prefecture, Japan, 2012Fukushima prefecture, Japan, 2012

Fukushima prefecture, Japan, 2012

La pollution de l'air en France : 48 000 morts par an !

9 Décembre 2016,

Publié par Bioécologie

La pollution de l’air due aux particules fines est responsable de 48 000 morts chaque année en France, dont plus de 34 000 seraient évitables, selon une étude de Santé Publique France.

En savoir plus ici

Découvrez ici la carte de France de la pollution atmosphérique.

Crédit photo : Damián Bakarcic

Crédit photo : Damián Bakarcic

Emission of spherical cesium-bearing particles from an early stage of the Fukushima nuclear accident

29 Juin 2016,

Publié par Bioécologie

Abstract

The Fukushima nuclear accident released radioactive materials into the environment over the entire Northern Hemisphere in March 2011, and the Japanese government is spending large amounts of money to clean up the contaminated residential areas and agricultural fields. However, we still do not know the exact physical and chemical properties of the radioactive materials. This study directly observed spherical Cs-bearing particles emitted during a relatively early stage (March 14–15) of the accident. In contrast to the Cs-bearing radioactive materials that are currently assumed, these particles are larger, contain Fe, Zn, and Cs, and are water insoluble. Our simulation indicates that the spherical Cs-bearing particles mainly fell onto the ground by dry deposition. The finding of the spherical Cs particles will be a key to understand the processes of the accident and to accurately evaluate the health impacts and the residence time in the environment.

(a) A Cs-bearing particle partially embedded within a carbon paste. (b) The same Cs-bearing particle as a) but measured the next day. The particle shows a spherical shape. (c) An elemental mapping (Cs) of the particle (a). (d) The EDS spectrum of the particle a) (black line). The red line shows the spectrum from the glass substrate. The Cs in the particle shows multiple peaks. (e) An elemental mapping of the other elements within the area. O, Si, Cl, Mn, Fe, and Zn are possibly coexistent with Cs within the particle.

(a) A Cs-bearing particle partially embedded within a carbon paste. (b) The same Cs-bearing particle as a) but measured the next day. The particle shows a spherical shape. (c) An elemental mapping (Cs) of the particle (a). (d) The EDS spectrum of the particle a) (black line). The red line shows the spectrum from the glass substrate. The Cs in the particle shows multiple peaks. (e) An elemental mapping of the other elements within the area. O, Si, Cl, Mn, Fe, and Zn are possibly coexistent with Cs within the particle.

ERICA Assessment Tool

28 Juin 2016,

Publié par Bioécologie

The ERICA Tool is a software system that has a structure based upon the tiered ERICA Integrated Approach to assessing the radiological risk to terrestrial, freshwater and marine biota. The Tool guides the user through the assessment process, recording information and decisions and allowing the necessary calculations to be performed to estimate risks to selected animals and plants.

More information here

ERICA Assessment Tool

Internal structure of cesium-bearing radioactive microparticles released from Fukushima nuclear power plant

28 Juin 2016,

Publié par Bioécologie

Abstract

Microparticles containing substantial amounts of radiocesium collected from the ground in Fukushima were investigated mainly by transmission electron microscopy (TEM) and X-ray microanalysis with scanning TEM (STEM). Particles of around 2 μm in diameter are basically silicate glass containing Fe and Zn as transition metals, Cs, Rb and K as alkali ions, and Sn as substantial elements. These elements are homogeneously distributed in the glass except Cs which has a concentration gradient, increasing from center to surface. Nano-sized crystallites such as copper- zinc- and molybdenum sulfide, and silver telluride were found inside the microparticles, which probably resulted from the segregation of the silicate and sulfide (telluride) during molten-stage. An alkali-depleted layer of ca. 0.2 μm thick exists at the outer side of the particle collected from cedar leaves 8 months after the nuclear accident, suggesting gradual leaching of radiocesium from the microparticles in the natural environment.

Read more here

(a) Element maps of NWC-1 acquired by STEM-EDS with a STEM Dark-field (DF) image at the same area, and (top) TEM Bright-field image in which the rectangle indicates the area analyzed by STEM-EDS. The thin area around the top of the particle which was not observed in Fig. 1a was formed by a further thinning process by FIB. (b) Element maps and images of CB-8 with the same framing as in (a).

(a) Element maps of NWC-1 acquired by STEM-EDS with a STEM Dark-field (DF) image at the same area, and (top) TEM Bright-field image in which the rectangle indicates the area analyzed by STEM-EDS. The thin area around the top of the particle which was not observed in Fig. 1a was formed by a further thinning process by FIB. (b) Element maps and images of CB-8 with the same framing as in (a).

L'or noir de l'Amérique - Un film sur le pétrole de schiste dans le Dakota du Nord

13 Mai 2016,

Publié par Bioécologie

Un documentaire réalisé par Pierre-Emmanuel Luneau-Daurignac (52’). Ce documentaire a été diffusé sur La Chaîne Parlementaire (LCP, France). Cette chaîne de télévision a été créée en 1999 par l’Assemblée nationale et le Sénat français.

Synopsis :

"En 2009, la découverte d’un gigantesque gisement de pétrole de schiste dans le Dakota du Nord sonne comme une bonne nouvelle pour l’Amérique en crise. Plus de 16 000 puits pompent aujourd’hui le sol du Dakota du Nord. Les Etats-Unis devraient devenir le premier producteur de pétrole d’ici à 2020, devant la Russie et l’Arabie Saoudite, remettant ainsi en cause une bonne partie de l’équilibre géostratégique de la planète. Mais alors que l’argent et le pétrole coulent à flots, d’autres voix se font entendre : celles des fermiers de la région dont le bétail dépérit à vue d’œil, celles des habitants des petites villes dont l’eau potable s’irise soudain. Le réalisateur est parti enquêter sur ce nouveau Far West et ses acteurs, avec en toile de fond les enjeux économiques gigantesques des hydrocarbures de schiste, mais aussi les enjeux de santé publique…"

Las superbacterias que viven en Chernóbil

21 Avril 2016,

Publié par Bioécologie

Un equipo científico halla unos microbios resistentes a la radioactividad, lo que puede tener implicaciones en la lucha contra el cáncer

Kristin Suleng (Valencia, 24 mars 2016):

Aunque su nombre recuerda a una de las mayores catástrofes medioambientales de la historia, Chernóbil no es sinónimo de ausencia absoluta de vida. En el escenario inhóspito que dejó el accidente nuclear hay poco rastro de presencia humana, pero algunas especies de vegetales, insectos y aves son capaces de resistir la radiactividad 30 años después del desastre. ¿El hecho de vivir en ambientes radiactivos podría generar una resistencia a la radiactividad? Esa es la pregunta fundamental que plantea un reciente estudio publicado en la revista Scientific Reports, el primero en confirmar la resistencia de ciertas bacterias a dosis intermedias de radiactividad, fruto de un trabajo liderado por el biólogo español Mario Xavier Ruiz-González.

Las bacterias pueden sobrevivir en el lugar más insospechado del planeta. También en los entornos radiactivos. Esa es la hipótesis inicial de esta investigación pionera que considera la radiactividad como una condición de estrés, al igual que las temperaturas extremas, a las que se adaptan los animales y las plantas como motor de los procesos evolutivos.

Aunque descubrir los efectos negativos de la radiactividad sobre los microorganismos no es una novedad, en cambio, lo es demostrar la adaptación de las bacterias a ambientes radiactivos. Investigaciones previas han caracterizado la vida en Chernóbil a partir de la detección de mutaciones y aberraciones en plantas, insectos, hongos y bacterias, o de la evaluación del impacto de la radiactividad sobre la biodiversidad. Pero el estudio de este investigador valenciano es el primero en analizar la resistencia de las bacterias tras el desastre nuclear.

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Chernobyl Nuclear Power Plant's reactor 4

Chernobyl Nuclear Power Plant's reactor 4

Neurodevelopmental Disorders and Prenatal Residential Proximity to Agricultural Pesticides: The CHARGE Study

3 Février 2016,

Publié par Bioécologie

By Janie F. Shelton, Estella M. Geraghty, Daniel J. Tancredi, Lora D. Delwiche, Rebecca J. Schmidt, Beate Ritz, Robin L. Hansen, and Irva Hertz-Picciotto. June 2014.

  • Background: Gestational exposure to several common agricultural pesticides can induce developmental neurotoxicity in humans, and has been associated with developmental delay and autism.

    Objectives: We evaluated whether residential proximity to agricultural pesticides during pregnancy is associated with autism spectrum disorders (ASD) or developmental delay (DD) in the Childhood Autism Risks from Genetics and Environment (CHARGE) study.

    Methods: The CHARGE study is a population-based case–control study of ASD, DD, and typical development. For 970 participants, commercial pesticide application data from the California Pesticide Use Report (1997–2008) were linked to the addresses during pregnancy. Pounds of active ingredient applied for organophophates, organochlorines, pyrethroids, and carbamates were aggregated within 1.25-km, 1.5-km, and 1.75-km buffer distances from the home. Multinomial logistic regression was used to estimate the odds ratio (OR) of exposure comparing confirmed cases of ASD (n = 486) or DD (n = 168) with typically developing referents (n = 316).

    Results: Approximately one-third of CHARGE study mothers lived, during pregnancy, within 1.5 km (just under 1 mile) of an agricultural pesticide application. Proximity to organophosphates at some point during gestation was associated with a 60% increased risk for ASD, higher for third-trimester exposures (OR = 2.0; 95% CI: 1.1, 3.6), and second-trimester chlorpyrifos applications (OR = 3.3; 95% CI: 1.5, 7.4). Children of mothers residing near pyrethroid insecticide applications just before conception or during third trimester were at greater risk for both ASD and DD, with ORs ranging from 1.7 to 2.3. Risk for DD was increased in those near carbamate applications, but no specific vulnerable period was identified.

    Conclusions: This study of ASD strengthens the evidence linking neurodevelopmental disorders with gestational pesticide exposures, particularly organophosphates, and provides novel results of ASD and DD associations with, respectively, pyrethroids and carbamates.

More here

La Mort est dans le pré

2 Décembre 2015,

Publié par Bioécologie

Dans son film, Eric Gueret enquête sur les conséquences de l'utilisation de pesticides pouvant provoquer des maladies graves chez les agriculteurs. Il montre comment et pourquoi les paysans tombent malades à cause des produits phytosanitaires utilisés au quotidien sur leurs terres.