The Beagle Channel is a remote subantarctic environment where mussel aquaculture initiatives have existed since the early 1990s. Here we analyze phytoplankton biomass and composition, and the occurrence of harmful microalgae species and their toxins at three sites during the period 2015–2016. The occurrence of potentially harmful algae was observed throughout the study period, including toxigenic dinoflagellates such as Alexandrium catenella (Group I of the A. tamarense complex), A. ostenfeldii, Dinophysis acuminata, Gonyaulax spinifera, Azadinium sp., and the diatoms Pseudo-nitzschia australis and P. fraudulenta. Toxic dinoflagellates were detected in low densities whereas a Pseudo-nitzschia bloom was observed in late February. Isolates of A. catenella and P. delicatissima sensu stricto were phylogenetically characterized. The toxin profile of A. catenella was dominated by GTX4, while P. delicatissima sensu stricto showed no production of the neurotoxin domoic acid in culture conditions. The results provide base-line information for the management of harmful algal blooms in this little explored subantarctic area.

Proceedings of the 2nd International Conference on Microplastic Pollution in the Mediterranean Sea, Capri, ITALIE, 15-/09/2019 - 18/09/2019 | International audience | Nowadays, microplastic (MPs) pollution is well documented in marine ecosystems since the first publication alarming about marine plastic pollution in 1972 [1]. Similarly, continental contamination is more and more investigated. More recently, interest for estuarine systems is growing. Estuaries are considered as a suspected predominant pathway for microplastic pollution from continent to oceans. The specific conditions of estuaries, like salinity gradient, tides and hydrodynamics, could affect the repartition, settling and transfer of microplastics to marine systems.

International audience | Biocides are added to or applied on building materials to prevent microorganisms from growing on their surface or to treat them. They are leached into building runoff and contribute to diffuse contamination of receiving waters. This review aimed at summarizing the current state of knowledge concerning the impact of biocides from buildings on the aquatic environment. The objectives were (i) to assess the key parameters influencing the leaching of biocides and to quantify their emission from buildings; (ii) to determine the different pathways from urban sources into receiving waters; and (iii) to assess the associated environmental risk. Based on consumption data and leaching studies, a list of substances to monitor in receiving water was established. Literature review of their concentrations in the urban water cycle showed evidences of contamination and risk for aquatic life, which should put them into consideration for inclusion to European or international monitoring programs. However, some biocide concentration data in urban and receiving waters is still missing to fully assess their environmental risk, especially for isothiazolinones, iodopropynyl carbamate, zinc pyrithione and quaternary ammonium compounds, and little is known about their transformation products. Although some models supported by actual data were developed to extrapolate emissions on larger scales (watershed or city scales), they are not sufficient to prioritize the pathways of biocides from urban sources into receiving waters during both dry and wet weathers. Our review highlights the need to reduce emissions and limit their transfer into rivers, and reports several solutions to address these issues.

This is the post-print version of the following article: "Threats Underestimated in Freshwater Plastic Pollution: Mini-Review", which has been published in final form at https://link.springer.com/article/10.1007/s11270-019-4220-z | International audience | Plastic pollution is one of the most acute environmental topics of our time. While there is a great scientific effort to tackle this problem, it has not always been well-coordinated or properly targeted. In this short review we call for scientists to get involved in three crucial topics (threats) underestimated-or ignored-in freshwater systems: i) plastic-species entanglement, ii) plastic as nesting material and iii) macroplastic debris coming from mismanaged household solid waste. Reducing the knowledge gaps between marine and freshwater environments will be crucial to solute the plastic pollution problem effectively and globally. Therefore, we make a plea here to reinforce research activities on these three issues in freshwater environments worldwide.

Today, the environmental awareness is leading to the recovery of the solid organic waste and the use of fossil fuels. Methanisation, or anaerobic digestion, is a solution. This process is the transformation of organic matter by bacteria in the absence of oxygen. It allows both the treatment of organic waste and provides two main products biogas and digestate. Digestate is an improved fertilizer that can be used by spreading or composting. Biogas can be used to produce heat or electricity. Biogas production is currently supported by governments of developed countries. In France, the number of installations is gradually increasing (Club Biogaz ATEE, 2011). However, waste used as raw material can potentially be rich in microorganisms. Currently, some questions arise about the potential spread of micro-organisms by this type of process. Among the among the dispersal pathways, the airborne mode of spread is often poorly explored. During the anaerobic process, a few phases seem to be able to cause the aerosolization of microorganisms, for example, the stock of raw materials or digestate handling. In this context, the EMAMET project was realised to provide data on atmospheric emissions from these processes (Bayle et al, 2016). The objectives of this study are to enumerate and describe the airborne microbial community on anaerobic digestor site caracterized by molecular approach. On a quarterly basis, over a one-year period, of the anaerobic digestion of waste water activated sludge has been monitored. For each campaign, four sampling locations have been investigated; the storage area for raw materials, the raw material preparation area, the digestion reactor and the phase separation zone of the digestate. A fifth simple, an outdoor control sampling point was also included.

The rapid dissemination of microplastics in many habitats of the oceans has raised concerns about the consequences for marine biota and ecosystems. Many adverse effects of microplastics on marine invertebrates are consequences of ingestion. Accordingly, the identification of mechanisms that facilitate the uptake of microplastics is essential for the evaluation of possible implications for marine organisms and food webs. Gastropods produce mucus for locomotion. Gastropod pedal mucus naturally retains formerly suspended micro-organisms, such as bacteria, microalgae, and seaweed spores. The retained organisms are consumed by gastropods that forage on pedal mucus. Here, we investigated the potential of gastropod pedal mucus to retain suspended microplastic particles and make them available for ingestion by periwinkles that forage on the contaminated mucus. In laboratory experiments, mucus of the periwinkles Littorina littorea and Littorina obtusata efficiently retained microplastics. Retention of microplastics varied between mucus from conspecifics of different size but not between mucus from either species. The density of microplastics in mucus trails increased concomitantly with the experimental particle concentration but was independent of incubation time. Aging of mucus and, particularly, desiccation affected the retention of microplastics. Periwinkles ingested microplastics when foraging on the contaminated mucus. Our results reveal a functional link between biogenic accumulation of microplastics and their trophic transfer by marine benthic herbivores into marine food webs.

International audience

In early nineteen century, a gas field was operational in southern part of Sindh, Pakistan for power production. The plant was completely un-operational for last three decades, whereas all wastage and raw materials are still dumped there, which might be the source to contaminate the ground water. The most of the workers population still living in different villages nearby the gas field. In present study, evaluated the undesirable effects of the toxic metals (lead and cadmium) via consuming groundwater for drinking and other domestic purpose especially in children of ≤5.0 years. For comparative purpose groundwater of nonindustrial area (nonexposed) was also analysed and their impact on age matched children was carried out. Biological samples (scalp hair and blood) were collected from children of exposed and nonexposed areas. The Cd and Pb in scalp hair and blood samples were carried out by graphite furnace atomic absorption spectrometry. Whereas, Cd and Pb in groundwater obtained from both areas were determined prior to applied preconcentration method as reported in our previous works. The Cd and Pb contents in the groundwater of villages of exposed area were found in the range of 5.18–10.9 and 19.9–69.5 μg/L, respectively. Whereas, the groundwater of nonexposed area contains Cd and Pb in the range of 1.79–3.78 and 5.07–24.3 μg/L, respectively. It was observed that the concentrations of Cd and Pb in scalp hair and blood samples of children belongs to exposed area have ≥2.0 fold higher than the resulted data attained for age matched control children, indicating as the exposure biomarkers of toxic metals. The children belong to exposed area have poor health, anemic and low body mass index (<13 kg/m2). A significant positive correlations among Cd and Pb concentrations in biological samples of exposed subjects and groundwater was observed (p < 0.01).

A study was undertaken to test the hypothesis that the presence of fly ash and other artifactual materials (AMs) significantly increases the toxicity of urban soil and street dust. AMs were distinguished as artifacts (artificial particles > 2 mm in size), and particulate artifacts (≤2 mm in size); street dust was the <63 μm fraction of street sediments. Reference artifacts, street dusts, and topsoils representing different land use types in Detroit, Michigan were analyzed for miscellaneous radionuclides, trace elements, magnetic susceptibility (MS), and acetic acid-extractable (leachable) Pb. Background levels were established using native glacial sediments. Street sediments were found to have a roadside provenance, hence street dusts inherited their contamination primarily from local soils. All soils and dusts had radionuclide concentrations similar to background levels, and radiological hazard indices within the safe range. Artifacts, fly ash-impacted soils and street dusts contained elevated concentrations of toxic trace elements, which varied with land use type, but none produced a significant amount of leachable Pb. It is inferred that toxic elements in AMs are not bioavailable because they are occluded within highly insoluble materials. Hence, these results do not support our hypothesis. Rather, AMs contribute to artificially-elevated total concentrations leading to an overestimation of toxicity. MS increased with increasing total concentration, hence proximal sensing can be used to map contamination level, but the weak correlation between total and leachable Pb suggests that such maps do not necessarily indicate the associated biohazard. Home site soils with total Pb concentrations >500 mg kg−1 were sporadically toxic. Thus, these results argue against street dust as the local cause of seasonally elevated blood-Pb levels in children. Lead-bearing home site soil tracked directly indoors to form house dust is an alternative exposure pathway.