In parallel with the growing use of nanoparticle-containing products, their release into the environment over the coming years is expected to increase significantly. With many large population centers located in near-coastal areas, and increasing evidence that various nanoparticles may be toxic to a range of organisms, biota in estuarine and coastal waters may be particularly vulnerable. While size effects may be important in cases, silver nanoparticles have been found to be toxic in large part due to their release of silver ions. However, there is relatively little data available on how nanoparticle coatings can affect silver ion release in estuarine or marine waters. We have found that albumin, as a model for biocorona-forming macromolecules which nanoparticles may encounter in wastewater streams, stabilizes silver colloids from agglomeration in high salinity marine waters by electrosteric repulsion for long time periods. A minimum mass ratio of about 130 for albumin:silver nanoparticles (40 nm) was required for stable dispersion in seawater. Increasing albumin concentration was also found to reduce dissolution of nanoparticles in seawater with up to 3.3 times lower concentrations of silver ions noted. Persistent colloids and slow sustained ion release may have important consequences for biota in these environmental compartments.

The widespread use of rare earth elements (REEs) in a number of technological applications raises unanswered questions related to REE-associated adverse effects. We have previously reported on the multiple impact of some REEs on the early life stages of the sea urchin Paracentrotus lividus. The present investigation was to evaluate REE toxicity to early life stages in two unrelated sea urchin species, Sphaerechinus granularis and Arbacia lixula. The comparative toxicities were tested of seven REEs, namely yttrium, lanthanum, cerium, neodymium, samarium, europium and gadolinium as chloride salts at concentrations ranging from 10 to 10 M. The evaluated endpoints included developmental defects and cytogenetic anomalies in REE-exposed embryos/larvae, and decreased fertilization success and offspring damage following sperm exposure. The results showed different toxicity patterns for individual REEs that varied according to test species and to treatment protocol, thus showing toxicity scaling for the different REEs. Further, the observed effects were compared with those reported for P. lividus either following embryo or sperm exposures. S. granularis showed a significantly higher sensitivity both compared to A. lixula and to P. lividus. This study provides clear-cut evidence for distinct toxicity patterns among a series of REEs. The differences in species sensitivity at micromolar REE levels may warrant investigations on species susceptibility to impacts along polluted coasts.

The effect of styrene-ethylene/butylene-styrene block copolymer (SEBS) on the thermal degradation of polystyrene (PS)/high density polyethylene (HDPE) blends have been investigated. Polystyrene and (HDPE) are widely used thermoplastics, which have extensive application in everyday life. The main disadvantage of PS/PE systems is their poor miscibility which can be improved by adding compatibilizer. The blends were prepared by melt mixing in a twin screw extruder Haake Record 90. The behavior of the thermal degradation of PS/HDPE and PS/HDPE/SEBS blends has been investigated in inert nitrogen atmosphere by using thermogravimetric analysis (TGA) to obtain the degradation temperature and activation energy ( E a). The Ea for the PS/HDPE blends as well as for the PS/HDPE/SEBS blends was determined by the isoconversional Kissinger–Akahira–Sunose (KAS) method. The results indicated that the HDPE enhance thermal properties of the blends. The addition of SEBS in PS/HDPE blends increased the E a in all blends.