International audience | The use of organic plastic additives (OPAs) in food packaging has led to their widespread presence in various foodstuffs. These additives, including mainly flame-retardants, bisphenols, UV-stabilizers and plasticizers, are known for their potential hazards and environmental impact. This review aims to comprehensively assess the contamination of food products by OPAs and evaluate their role as vectors of exposure to hazardous chemicals. A review of recent literature was conducted, focusing on studies that report on the presence and concentrations of OPAs in different food categories, including aquatic products, beverages, cereals, dairy products, eggs, oils, fats, meat, poultry, vegetables, fruits and other food categories. The review also examines regional variations in contamination levels and identifies the pollutants. Significant contamination of foodstuffs by OPAs are highlighted, with varying concentrations reported across different regions and food types. Potential sources of contamination include food-packaging materials and environmental pollution. This review also identifies research gaps and proposes future directions to improve the study of OPAs in food, aiming to enhance the reliability and comparability of findings while supporting efforts to mitigate contamination risks.

fff | International audience | The potential success of microalgal biofuels greatly depends on the sustainability of the chosen pathway to produce them. Hydrothermal liquefaction (HTL) is a promising route to convert wet algal biomass into biocrude. Recycling the resulting HTL aqueous phase (AP) aims not only to recover nutrients from this effluent but also to use it as a substrate to close the photosynthetic loop and produce algal biomass again and process this biomass again into new biocrude. With that purpose, the response to AP recycling of five Chlorellaceae strains was monitored over five cultivation cycles. After four successive cycles of dynamic growth under nutrient-replete conditions, the microalgae were cultivated for a prolonged fifth cycle of 18 days in order to assess the impact of the AP on lipid and biomass accumulation under nutrient-limited conditions. Using AP as a substrate reduced the demand for external sources of N, S, and P while producing a significant amount of biomass (2.95-4.27 g/L) among the strains, with a lipid content ranging from 16 to 36%. However, the presence of the AP resulted in biomass with suboptimal properties, as it slowed down the accumulation of lipids and thus reduced the overall energy content of the biomass in all strains. Although Chlorella vulgaris NIES 227 did not have the best growth on AP, it did maintain the best lipid productivity of all the tested strains. Understanding the impact of AP on microalgal cultivation is essential for further optimizing biofuel production via the HTL process.

International audience | Biomagnetic monitoring increasingly is applied to assess particulate matter (PM) concentrations, mainly using plant leaves sampled in small geographical area and from a limited number of species. Here, the potential of magnetic analysis of urban tree trunk bark to discriminate between PM exposure levels was evaluated and bark magnetic variation was investigated at different spatial scales. Trunk bark was sampled from 684 urban trees of 39 genera in 173 urban green areas across six European cities. Samples were analysed magnetically for the Saturation Isothermal Remanent Magnetisation (SIRM). The bark SIRM reflected well the PM exposure level at city and local scale, as the bark SIRM (i) differed between the cities in accordance with the mean atmospheric PM concentrations and (ii) increased with the cover of roads and industrial area around the trees. Furthermore, with increasing tree circumferences, the SIRM values increased, as a reflection of a tree age effect related to PM accumulation over time. Moreover, bark SIRM was higher at the side of the trunk facing the prevailing wind direction. Significant relationships between SIRM of different genera validate the possibility to 2 combine bark SIRM from different genera to improve sampling resolution and coverage in biomagnetic studies. Thus, the SIRM signal of trunk bark from urban trees is a reliable proxy for atmospheric coarse to fine PM exposure in areas dominated by one PM source, as long as variation caused by genus, circumference and trunk side is taken into account.

International audience | Temperature is a key factor that influences pesticide degradation. Extrapolating degradation half-lives (DT50) measured at a given temperature to different temperatures remains challenging, especially for tropical conditions with high temperatures. In this study, the use of the standard Arrhenius equation for correcting temperature effects on pesticide degradation in soils was evaluated and its performance was compared with that of alternative Arrhenius-based equations. To do so, a database of 509 DT50 values measured between 5 and 35 °C for 32 pesticides on tropical and temperate soils was compiled for the first time through an extensive literature search. The temperature correction models were fitted to the database using linear mixed regression approaches that included soil type and compound effects. No difference in the temperature dependence of DT50 between tropical and temperate soils was detected, regardless of the model. A comparison of the prediction performances of the models showed that constant activation energy (Ea) cannot be considered valid for the whole range of temperatures. The classical Arrhenius equation with an Ea of 65.4 kJ.mol−1, as recommended by the European Food Safety Authority (EFSA), was shown to be valid for correcting the DT50 only for temperatures ranging from 5 to 20 °C. However, for temperatures greater than 20 °C, which are common in tropical environments, the median Ea was significantly lower at 10.3 kJ.mol−1. These findings suggest the need to adapt the standard temperature correction of the European pesticide risk assessment temperature procedure when it is applied in tropical settings

National audience | This paper aims at gaining an insight into the PM10 daily threshold (50 micro g/m3) exceedances measured by French regional air quality monitoring networks for the last four years. As almost three quarter of these exceedances happens to occur between November and April, we focus here on such winter (broadly speaking) pollution episodes. The deployment of monitoring devices allowing for a proper account of semi-volatile material within PM10 was achieved concomitantly to the development particulate pollution episodes largely influenced by ammonium nitrate (which is semi-volatile) in March-April 2007. Since then, such pollution events are frequently observed at this period of the year, notably due to stable meteorological conditions favoring the condensation of semi-volatile material into the particulate phase along with the resumption of manure spreading, which constitutes a major source of ammonium nitrate gaseous precursors (at least at some points of the year). Such pollution events, which are also related to combustion emissions (among which mobile sources) are typically preceded, from November to February, by frequent daily threshold exceedances with potentially significant influences of biomass burning (e.g. residential wood burning). The winter period is also impacted by long range transport episodes, corresponding notably to increases of ammonium sulfate relative abundances within PM10. Moreover, as traffic sites are generally the first ones showing PM10 exceedances due the increment of direct emissions and resuspension processes, mobile sources are also considered as a major target for action plans. Finally, it is underlined that the occurrence of daily threshold exceedances is highly influenced by meteorological conditions, so that the yearly number of these exceedances shows well-marked inter-annual variations, with 2009 and 2011 (and 2012, but not shown here) being significantly more polluted than 2008 and 2010. The on-going development of efficient forecasting systems still suffer lacks of detailed emission inventories and strong knowledge on the physical and chemical transformation processes of particles and their gaseous precursors within the boundary layer. | Cette synthèse dresse une analyse non exhaustive des dépassements du seuil réglementaire journalier de 50 micro g/m3 pour les PM10 mesurés au niveau national par les Associations Agréées de Surveillance de la Qualité de l'Air (AASQA) au cours des quatre dernières années. Près des trois quarts de ces dépassements étant observés entre fin novembre et début avril, nous nous intéressons plus particulièrement ici à ces épisodes hivernaux (au sens large). La mise en oeuvre de techniques analytiques permettant une prise en compte correcte des espèces semi-volatiles dans la composition des PM10 a coïncidé en mars-avril 2007 à la survenue de nombreux dépassements de seuil journalier s'accompagnant d'importants niveaux de nitrate d'ammonium (composé semi-volatil). Ce type d'épisode est régulièrement observé à cette période. Il s'explique notamment par la conjonction de conditions atmosphériques stables et propices à la condensation en phase particulaire des espèces labiles, et de la reprise des épandages agricoles, constituant une source majeure, au moins ponctuellement, de précurseurs gazeux azotés du nitrate d'ammonium. Ce type d'épisode, mettant également en cause les émissions anthropiques de combustion (dont les transports), est typiquement précédé entre novembre et février de fréquents dépassements pour lesquels le rôle des combustions de biomasse (incluant notamment le chauffage au bois individuel) peut être important. La période hivernale est également marquée par l'occurrence de phénomènes de transport longue distance se caractérisant par une augmentation des contributions du sulfate d'ammonium. Les sites de proximité automobile étant généralement les premiers concernés par les dépassements du seuil journalier en raison du surplus de concentrations provenant des émissions à l'échappement et des phénomènes de remise en suspension, le transport routier est également considéré comme un levier incontournable pour le respect des valeurs limites. Enfin, il est souligné que l'occurrence des différents types d'épisodes de dépassements dépend fortement des conditions météorologiques, de sorte qu'on observe une forte variabilité interannuelle du nombre de dépassements hivernaux ? : 2009 et 2011 (et 2012) étant significativement plus impactées que 2008 et 2010. Une bonne prévision de ces épisodes passe encore par l'affinage des cadastres d'émission et une meilleure compréhension du devenir dans l'atmosphère des émissions primaires (gazeuses et particulaires).

Poster session | International audience

Poster session | International audience

Monographie en Série : Integrated Environmental Technology Series, Lens, P. (Ed.) | International audience | Environmental Technologies to Treat Nitrogen Pollution will provide a thorough understanding of the principles and applications of environmental technologies to treat nitrogen contamination. The main focus will be on water and wastewater treatment, with additional coverage of leachates and off-gasses. The book will bring together an up-to-date compilation of the main physical, chemical and biological processes demanded for the removal of nitrogenous contaminants from water, wastewater, leachates and off-gasses. It will include a series of chapters providing a deep and broad knowledge of the principles and applications required for the treatment of nitrogen pollution. Each chapter will be prepared by recognized specialists across the range of different aspects involved in the removal of nitrogenous contaminants from industrial discharges. Environmental Technologies to Treat Nitrogen Pollution will be the first book to provide a complete review of all the different processes used for the global management of nitrogen pollution. It will also contain updated information about strategies to achieve nitrogen recovery and reuse in different industrial sectors. Several case studies will document the application of different environmental technologies to manage nitrogen pollution. This book will be of interest to lecturers and graduate students in the following subject areas: Environmental Engineering, Environmental Biotechnology, wastewater treatment plant design, water pollution control, contaminants recovery and reuse. The book will also be an attractive reference for environmental engineering consultants.