Metals and marine microplastics: Adsorption from the environment versus addition during manufacture, exemplified with lead.

There are two means by which metals associate with microplastics in the aquatic environment. Firstly, they may be adsorbed to the plastic surface or hydrogenous-biogenic accumulations thereon, and secondly, they may be present in the polymeric matrix as functional additives or as reaction or recyclate residues. In this study, the relative significance of these associations is evaluated with respect to Pb in beached marine microplastics.

Gills are an initial target of zinc oxide nanoparticles in oysters Crassostrea gigas, leading to mitochondrial disruption and oxidative stress.

The increasing industrial use of nanomaterials during the last decades poses a potential threat to the environment and in particular to organisms living in the aquatic environment. In the present study, the toxicity of zinc oxide nanoparticles (ZnONP) was investigated in Pacific oysters Crassostrea gigas. The nanoscale of ZnONP, in vehicle or ultrapure water, was confirmed, presenting an average size ranging from 28 to 88 nm.

Enhanced toxicity of 'bulk' titanium dioxide compared to 'fresh' and 'aged' nano-TiO2 in marine mussels (Mytilus galloprovincialis).

Marine bivalves (Mytilus galloprovincialis) were exposed to titanium dioxide (10 mg L(-1)) either as engineered nanoparticles (nTiO2; fresh, or aged under simulated sunlight for 7 days) or the bulk equivalent. Inductively coupled plasma-optical emission spectrometry analyses of mussel tissues showed higher Ti accumulation (>10-fold) in the digestive gland compared to gills. Nano-sized TiO2 showed greater accumulation than bulk, irrespective of ageing, particularly in digestive gland (>sixfold higher).

Relative sensitivity of two marine bivalves for detection of genotoxic and cytotoxic effects: a field assessment in the Tamar Estuary, South West England.

The input of anthropogenic contaminants to the aquatic environment is a major concern for scientists, regulators and the public. This is especially relevant in areas such as the Tamar valley in SW England, which has a legacy of contamination from industrial activity in the nineteenth and twentieth centuries. Following on from previous laboratory validation studies, this study aimed to assess the relationship between genotoxic and cytotoxic responses and heavy metal concentrations in two bivalve species sampled from locations along the Tamar estuary.

Selenium in water enhances antioxidant defenses and protects against copper-induced DNA damage in the blue mussel Mytilus edulis.

Selenium and copper are naturally occurring elements in the environment that have important roles in cellular function. Selenium is known for its role in antioxidant defense, whereas copper is a redox-active metal capable of acting as a pro-oxidant. We investigated the effects of short term selenium (Na(2)SeO(3)) supplementation (4 μg/L for 3 days) on antioxidant parameters of the blue mussel, Mytilus edulis, and its possible protective effects against a subsequent copper (CuSO(4)) exposure (56 μg/L for 3 days).

Uptake and biological responses to nano-Fe versus soluble FeCl3 in excised mussel gills.

Nano-Fe particle uptake was experimentally examined in vitro using excised gills and blood cells of the edible blue mussel Mytilus sp. Whole gills were exposed to both Fe(2)O(3) nanoparticles and a solution of the hydrated FeCl(3) salt, for up to 12 h, and blood cells for 30 min. Equimolar Fe(+3) in the nano- and the soluble form was estimated under the assumption of dense spherical particles accommodating the same number of Fe(+3) as in the dissolved salt solution, namely: 1,000 microg L(-1) Fe(2)O(3) equivalent to 100 microg L(-1) FeCl(3).

Protective effects of selenium on mercury-induced DNA damage in mussel haemocytes.

Little is known of the antioxidant role of selenium (Se) in aquatic invertebrates. We investigated the effects of Se on mercury-induced DNA damage in haemocytes from Mytilus edulis using alkaline single cell gel electrophoresis, that is, the Comet assay. The basal percentage tail DNA value for mussel haemocytes was 9.

Adsorption kinetics of platinum group elements in river water.

The uptake of platinum group elements (PGE) by different preparations of estuarine sediment suspended in filtered river water has been examined. For a given PGE, adsorption time courses to untreated sediment and to sediment whose hydrous metal oxides or organic matter had been removed by appropriate chemical treatments were similar. Adsorption of Rh(lll) and Pt(IV) proceeded via a first-order reversible reaction.

Genotoxic, cytotoxic and ontogenetic effects of tri-n-butyltin on the marine worm, Platynereis dumerilii (Polychaeta: Nereidae).

The genotoxic, cytotoxic and ontogenetic (embryo-larval) or developmental effects of tri-n-butyltin (TBT), were investigated in Platynereis dumerilii. Following the determination of maximum tolerated dose with regard to ontogenetic effects and mortality, early life stages of P. dumerilii were exposed to a range of TBT concentrations.