L’objectif de cette étude est de mettre en évidence l’influence sur les émissions et les performances d’un appareil de différents paramètres, comme l’humidité du bois, la présence d’écorce ou non, le calibre utilisé ainsi que le mode d’allumage. De nombreux résultats ressortent de cette étude. Tout d’abord, tous ces paramètres influent de manière considérable sur les émissions des appareils, notamment les émissions de particules, et ce, même à régime nominal. La présence d’écorce modifie la composition en carbone total des particules totales et implique l’émission d’un nouveau type de particule : les nano-cristaux. Une humidité élevée induit des niveaux de températures plus faibles. Ainsi, les émissions d’imbrûlés gazeux tels que les Composés Organiques Volatils vont augmenter de manière importante. Les émissions de particules, en quantité et en composition chimique, sont aussi significativement impactées par l’humidité du combustible. Deux modes d’allumage ont aussi été étudiés. Il s’avère qu’un allumage inversé permet de réduire de manière significative la globalité des émissions par rapport à un allumage classique. En effet, seules les émissions de Carbone Elémentaire sont plus importantes avec un allumage inversé. | he aim of this study is to bring to light the influence on firewood emissions and performance of several parameters like the moisture content of the fuel, the presence of bark, the caliber of the fuel but also the ignition mode. Many results emerge from this study. First of all, all these parameters significantly impact the emissions of the firewood at the nominal thermal heat output, especially the particles emissions. The presence of bark modifies the particles composition in total carbon. Moreover, the presence of bark induces the emissions of a new family of particles: the nanocrystal. A high moisture of the fuel led to a lower temperature in the combustion chamber. Then, the emissions of unburned gases, like the Volatile Organic Compounds, will considerably increase. The particles emissions and the composition of those particles were also significantly impacted by the moisture of the fuel. Two ignition modes were also studied. It appears that the top-down ignition against the traditional ignition allowed a significant decrease of all the emissions. Nevertheless, the elemental carbon emissions were more important with a top-down ignition.

International audience | he aim of this study is to bring to light the influence on firewood emissions and performance of several parameters like the moisture content of the fuel, the presence of bark, the caliber of the fuel but also the ignition mode. Many results emerge from this study. First of all, all these parameters significantly impact the emissions of the firewood at the nominal thermal heat output, especially the particles emissions. The presence of bark modifies the particles composition in total carbon. Moreover, the presence of bark induces the emissions of a new family of particles: the nanocrystal. A high moisture of the fuel led to a lower temperature in the combustion chamber. Then, the emissions of unburned gases, like the Volatile Organic Compounds, will considerably increase. The particles emissions and the composition of those particles were also significantly impacted by the moisture of the fuel. Two ignition modes were also studied. It appears that the top-down ignition against the traditional ignition allowed a significant decrease of all the emissions. Nevertheless, the elemental carbon emissions were more important with a top-down ignition. | L’objectif de cette étude est de mettre en évidence l’influence sur les émissions et les performances d’un appareil de différents paramètres, comme l’humidité du bois, la présence d’écorce ou non, le calibre utilisé ainsi que le mode d’allumage. De nombreux résultats ressortent de cette étude. Tout d’abord, tous ces paramètres influent de manière considérable sur les émissions des appareils, notamment les émissions de particules, et ce, même à régime nominal. La présence d’écorce modifie la composition en carbone total des particules totales et implique l’émission d’un nouveau type de particule : les nano-cristaux. Une humidité élevée induit des niveaux de températures plus faibles. Ainsi, les émissions d’imbrûlés gazeux tels que les Composés Organiques Volatils vont augmenter de manière importante. Les émissions de particules, en quantité et en composition chimique, sont aussi significativement impactées par l’humidité du combustible. Deux modes d’allumage ont aussi été étudiés. Il s’avère qu’un allumage inversé permet de réduire de manière significative la globalité des émissions par rapport à un allumage classique. En effet, seules les émissions de Carbone Elémentaire sont plus importantes avec un allumage inversé.

A combination of local (i.e. firefighting training facilities) and remote sources (i.e., long-range transport) are assumed to be responsible for the occurrence of per- and polyfluoroalkyl substances (PFASs) in Svalbard (Norwegian Arctic). However, no systematic elucidation of local PFASs sources have been conducted yet. Therefore, a survey was performed aiming at identifying local PFASs pollution sources on the island of Spitsbergen (Svalbard, Norway). Soil, fresh water (lake, draining rivers), sea water, melt-water run-off, surface snow and coastal sediment samples were collected from Longyearbyen (Norwegian mining town), Ny-Ålesund (research facility) and the Lake Linnévatnet area (background site) during several campaigns (2014-2016) and analysed for 14 individual target PFASs. For background site (Linnévatnet area, sampling during April to June 2015), ∑PFAS levels ranged from 0.4 – 4 ng/L in surface lake water (n = 20). PFAS in melt water from the contributing glaciers showed similar concentrations (~4 ng/L, n = 2). The short chain perfluorobutanoate (PFBA) was predominant in lake water (60-80% of the ∑PFASs), meltwater (20-30 %) and run-off water (40 %). Long range transport is assumed to be the major PFAS source. In Longyearbyen, 5 water samples (i.e. 2 seawater, 3 run-off) were collected near the local firefighting training site (FFTS) in November 2014 and June 2015, respectively. The highest PFAS levels were found in FFTS melt water run-off (118 ng/L). PFOS was the most abundant compound in the FFTS meltwater run-off (53 – 58 % PFASs). At the research station Ny-Ålesund, sea water (n = 6), soil (n = 9) and fresh water (n = 10) were collected in June 2016. Low ∑PFAS concentrations were determined for sea water (5 - 6 ng/L), whereas high ∑PFAS concentrations were found in run-off water (113 – 119 ng/L) and soil (211 – 800 ng/g dry weight (dw)) collected close to the local FFTS. In addition, high ∑PFAS levels (127 ng/L) were also found in fresh water from lake Solvatnet close to former sewage treatment facility. Overall, at both FFTS affected sites (soil, water), PFOS was the most abundant compound (60 – 69% of ∑PFASs). FFTS and landfill locations were identified as major PFASs sources for Svalbard settlements. | Elucidation of contamination sources for poly- and perfluoroalkyl substances (PFASs) on Svalbard (Norwegian Arctic) | acceptedVersion

A combination of local (i.e. firefighting training facilities) and remote sources (i.e., long-range transport) are assumed to be responsible for the occurrence of per- and polyfluoroalkyl substances (PFASs) in Svalbard (Norwegian Arctic). However, no systematic elucidation of local PFASs sources have been conducted yet. Therefore, a survey was performed aiming at identifying local PFASs pollution sources on the island of Spitsbergen (Svalbard, Norway). Soil, fresh water (lake, draining rivers), sea water, melt-water run-off, surface snow and coastal sediment samples were collected from Longyearbyen (Norwegian mining town), Ny-Ålesund (research facility) and the Lake Linnévatnet area (background site) during several campaigns (2014-2016) and analysed for 14 individual target PFASs. For background site (Linnévatnet area, sampling during April to June 2015), ∑PFAS levels ranged from 0.4 – 4 ng/L in surface lake water (n = 20). PFAS in melt water from the contributing glaciers showed similar concentrations (~4 ng/L, n = 2). The short chain perfluorobutanoate (PFBA) was predominant in lake water (60-80% of the ∑PFASs), meltwater (20-30 %) and run-off water (40 %). Long range transport is assumed to be the major PFAS source. In Longyearbyen, 5 water samples (i.e. 2 seawater, 3 run-off) were collected near the local firefighting training site (FFTS) in November 2014 and June 2015, respectively. The highest PFAS levels were found in FFTS melt water run-off (118 ng/L). PFOS was the most abundant compound in the FFTS meltwater run-off (53 – 58 % PFASs). At the research station Ny-Ålesund, sea water (n = 6), soil (n = 9) and fresh water (n = 10) were collected in June 2016. Low ∑PFAS concentrations were determined for sea water (5 - 6 ng/L), whereas high ∑PFAS concentrations were found in run-off water (113 – 119 ng/L) and soil (211 – 800 ng/g dry weight (dw)) collected close to the local FFTS. In addition, high ∑PFAS levels (127 ng/L) were also found in fresh water from lake Solvatnet close to former sewage treatment facility. Overall, at both FFTS affected sites (soil, water), PFOS was the most abundant compound (60 – 69% of ∑PFASs). FFTS and landfill locations were identified as major PFASs sources for Svalbard settlements. | Elucidation of contamination sources for poly- and perfluoroalkyl substances (PFASs) on Svalbard (Norwegian Arctic)

Embargo until 23 November 2019 | China's coastal environment has been heavily affected by the loading of terrestrial pollutants in recent decades, and quantitative risk assessment is urgently needed to assess the ecological risks of China's coastal environment. We assessed the ecological risks induced by five heavy metals (including Cu, Zn, Pb, Hg and As) in China's coastal waters for three groups of marine organisms (including crustacean, fish and mollusc) based on data obtained from a nationwide unified coastal environment monitoring program consisting of 301 sampling sites. The results show that higher heavy metal concentrations occurred more frequently in the Bohai Sea and in the estuaries of major sea-going rivers. The ecological risks decreased in the following order: Bohai Sea > Yellow Sea > South China Sea > East China Sea. There was generally low ecological risk, but certain hotspots existed near Tianjin and Jinzhou, which had relatively high ecological risks caused by Cu and Zn. | acceptedVersion

China's coastal environment has been heavily affected by the loading of terrestrial pollutants in recent decades, and quantitative risk assessment is urgently needed to assess the ecological risks of China's coastal environment. We assessed the ecological risks induced by five heavy metals (including Cu, Zn, Pb, Hg and As) in China's coastal waters for three groups of marine organisms (including crustacean, fish and mollusc) based on data obtained from a nationwide unified coastal environment monitoring program consisting of 301 sampling sites. The results show that higher heavy metal concentrations occurred more frequently in the Bohai Sea and in the estuaries of major sea-going rivers. The ecological risks decreased in the following order: Bohai Sea>Yellow Sea>South China Sea>East China Sea. There was generally low ecological risk, but certain hotspots existed near Tianjin and Jinzhou, which had relatively high ecological risks caused by Cu and Zn.

Biodegradation of chemically dispersed oil at low temperature (0–2 °C) was compared in natural seawater from Arctic (Svalbard) and a temperate (Norway) fjords. The oil was premixed with a dispersant (Corexit 9500) and small-droplet oil dispersions prepared. Faster biotransformation of n-alkanes in the Arctic than in the temperate seawater were associated with the initially higher abundance of the alkane-degrading genus Oleispira in the Arctic than the temperate seawater. Comparable transformation of aromatic hydrocarbons was further associated with the late emergences Cycloclasticus in both seawater sources. The results showed that chemically dispersed oil may be rapidly biodegraded by microbial communities in Arctic seawater. Compared to oil biodegradation studies at higher seawater temperatures, longer lag-periods were experienced here, and may be attributed to both microbial and oil properties at these low seawater temperatures. | acceptedVersion

Biodegradation of chemically dispersed oil at low temperature (0–2 °C) was compared in natural seawater from Arctic (Svalbard) and a temperate (Norway) fjords. The oil was premixed with a dispersant (Corexit 9500) and small-droplet oil dispersions prepared. Faster biotransformation of n-alkanes in the Arctic than in the temperate seawater were associated with the initially higher abundance of the alkane-degrading genus Oleispira in the Arctic than the temperate seawater. Comparable transformation of aromatic hydrocarbons was further associated with the late emergences Cycloclasticus in both seawater sources. The results showed that chemically dispersed oil may be rapidly biodegraded by microbial communities in Arctic seawater. Compared to oil biodegradation studies at higher seawater temperatures, longer lag-periods were experienced here, and may be attributed to both microbial and oil properties at these low seawater temperatures.

Subsea blowouts have the potential to spread oil across large geographical areas, and subsea dispersant injection (SSDI) is a response option targeted at reducing the impact of a blowout, especially reducing persistent surface oil slicks. Modified Weber scaling was used to predict oil droplet sizes with the OSCAR oil spill model, and to evaluate the surface oil volume and area when using SSDI under different conditions. Generally, SSDI reduces the amount of oil on the surface, and creates wider and thinner surface oil slicks. It was found that the reduction of surface oil area and volume with SSDI was enhanced for higher wind speeds. Overall, given the effect of SSDI on oil volume and weathering, it may be suggested that tar ball formation, requiring thick and weathered oil, could possibly be reduced when SSDI is used. | acceptedVersion

Subsea blowouts have the potential to spread oil across large geographical areas, and subsea dispersant injection (SSDI) is a response option targeted at reducing the impact of a blowout, especially reducing persistent surface oil slicks. Modified Weber scaling was used to predict oil droplet sizes with the OSCAR oil spill model, and to evaluate the surface oil volume and area when using SSDI under different conditions. Generally, SSDI reduces the amount of oil on the surface, and creates wider and thinner surface oil slicks. It was found that the reduction of surface oil area and volume with SSDI was enhanced for higher wind speeds. Overall, given the effect of SSDI on oil volume and weathering, it may be suggested that tar ball formation, requiring thick and weathered oil, could possibly be reduced when SSDI is used.

peer reviewed | Microplastics (MPs) are thought to be ingested by a wide range of marine organisms before being excreted. However, several studies in marine organisms from different taxa have shown that MPs and nanoplastics could be translocated in other organs. In this study, we investigated the presence of MPs in the livers of commercial zooplanktivorous fishes collected in the field. The study focuses mainly on the European anchovy Engraulis encrasicolus but concerns also the European pilchard Sardina pilchardus and the Atlantic herring Clupea harengus. Two complementary methodologies were used to attest the occurrence of MPs in the hepatic tissue and to exclude contamination. 1) MPs were isolated by degradation of the hepatic tissue. 2) Cryosections were made on the livers and observed in polarized light microscopy. Both methods separately revealed that MPs, mainly polyethylene (PE), were translocated into the livers of the three clupeid species. In anchovy, 80 per cent of livers contained relatively large MPs that ranged from 124 μm to 438 μm, showing a high level of contamination. Two translocation pathways are hypothesized: (i) large particles found in the liver resulted from the agglomeration of smaller pieces, and/or (ii) they simply pass through the intestinal barrier. Further studies are however required to understand the exact process. © 2017 Elsevier Ltd

International audience

Microplastics (MPs) are thought to be ingested by a wide range of marine organisms before being excreted. However, several studies in marine organisms from different taxa have shown that MPs and nanoplastics could be translocated in other organs. In this study, we investigated the presence of MPs in the livers of commercial zooplanktivorous fishes collected in the field. The study focuses mainly on the European anchovy Engraulis encrasicolus but concerns also the European pilchard Sardina pilchardus and the Atlantic herring Clupea harengus. Two complementary methodologies were used to attest the occurrence of MPs in the hepatic tissue and to exclude contamination. 1) MPs were isolated by degradation of the hepatic tissue. 2) Cryosections were made on the livers and observed in polarized light microscopy. Both methods separately revealed that MPs, mainly polyethylene (PE), were translocated into the livers of the three clupeid species. In anchovy, 80 per cent of livers contained relatively large MPs that ranged from 124 μm to 438 μm, showing a high level of contamination. Two translocation pathways are hypothesized: (i) large particles found in the liver resulted from the agglomeration of smaller pieces, and/or (ii) they simply pass through the intestinal barrier. Further studies are however required to understand the exact process.