Description: Every day new extraordinary properties of nanoparticles (a billionth of a meter) are discovered and worldwide millions are invested into nanotechnology and nanomaterials. As nanoparticles essentially differ from other environmental toxins, known mechanisms of toxicity do not apply. Man-made nanoparticles are introduced into the environment from multi-tons of carbon black and fumed silica for plastic fillers, car tyres and house insulation, kilograms in sunscreens, toothpaste, cosmetics, sanitary ware coatings, antifouling covers to micrograms as fluorescent quantum dots in biological imaging. According to the EU Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) toxicological risks assessment of nanoparticles should be based on particle size and shape (nanotubes and nanofibre such as glass wool and asbestos). Two areas are relevant here: (1) In free form nanoparticles can be released in the air or water during production (or production accidents) or as waste by product of production, and ultimately accumulate in the soil, water or plant life. (2) In fixed form, where they are part of a manufactured substance or product, they will ultimately have to be recycled or disposed of as waste. We used the filter feeding blue mussel as a model to analyse uptake and effects of nanoparticles from glass wool over a period of up to 60 days and measured lysosomal membrane stability and lipofuscin. By electron microscopic studies we analysed if and which size and shapes of particles were taken up by gills and into hepatopancreas. Lysosomal stability decreased significantly already after 24 h of exposure followed by lipofuscin accumulation indicating oxidative stress. Electronmicroscopy indicated inflammatory response, increased autophagy and silica fibre and dust accumulation in gills and hepatopancreas, mainly in the lysosomal system.

Description: Dissolved organic matter (DOM) is an important component in marine and freshwater environments and plays a fundamental role in global biogeochemical cycles. In the past, optical and molecular-level analytical techniques evolved and improved our mechanistic understanding about DOM fluxes. For most molecular chemical techniques, sample desalting and enrichment is a prerequisite. Solid-phase extraction has been widely applied for concentrating and desalting DOM. The major aim of this study was to constrain the influence of sorbent loading on the composition of DOM extracts. Here, we show that increased loading resulted in reduced extraction efficiencies of dissolved organic carbon (DOC), fluorescence and absorbance, and polar organic substances. Loading-dependent optical and chemical fractionation induced by the altered adsorption characteristics of the sorbent surface (styrene divinylbenzene polymer) and increased multilayer adsorption (DOM self-assembly) can fundamentally affect biogeochemical interpretations, such as the source of organic matter. Online fluorescence monitoring of the permeate flow allowed to empirically model the extraction process and to assess the degree of variability introduced by changing the sorbent loading in the extraction procedure. Our study emphasizes that it is crucial for sample comparison to keep the relative DOC loading (DOCload [wt %]) on the sorbent always similar to avoid chemical fractionation.

Description: Dumped warfare material like munitions, unexploded ordnances and sunken war ships carry a significant risk of chemical leakage, posing threats to marine wildlife. To assess the hazard potential of explosives on marine biota a multi-biomarker analysis was conducted using blue mussels (Mytilus edulis) and fish (Trisopterus luscus) exposed at munition containing war-wrecks in the Belgian part of the North Sea. Chosen biomarkers were lysosomal membrane stability (LMS), lipofuscin (LIPF), neutral lipids (NL), glycogen (GLY) and the enzyme activity of catalase (CAT), glutathione-S transferase (GST) and acetylcholinesterase (AChE). Samples were taken in October 2019 and July 2020 by divers.