Effects of nanoparticles in Mytilus edulis gills and hepatopancreas : A new threat to marine life?

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.