As the production and use of engineered nanomaterials increase, there is an urgent need to develop analytical techniques that are sufficiently sensitive to be able to measure the very small nanoparticles (NP) at very low concentrations. Although single particle ICP-MS (SP-ICP-MS) is emerging as one of the best techniques for detecting NP, it is limited by relatively high size detection limits for several NP, including many of the oxides. The use of a high sensitivity sector field ICP-MS (ICP-SF-MS), microsecond dwell times, and dry aerosol sample introduction systems were examined with the goal of lowering the size detection limits of the technique. For samples injected as a wet aerosol, size detection limits as low as 4.9 nm for Ag NP and 19.2 nm for TiO2 NP were determined. By using a dry aerosol, a significant gain in ion extraction from the plasma was obtained, which resulted in a noticeable decrease of the size detection limits to 3.5 nm for the Ag NP and 12.1 nm for the TiO2 NP. These substantial improvements were applied to the detection of TiO2 NP in sunscreen lotions, rainwaters, and swimming pool waters. Concentrations of Ti-containing NP between 27 and 193 μL–1 were found in rain samples. Similar NP concentrations were detected in public swimming pools, although much higher particle number concentrations (6046 ± 290 μL–1) were measured in a paddling pool, which was attributed to a high concentration of sunscreen lotions in a small recirculated water volume. High losses of TiO2 NP through adsorption or agglomeration resulted in recoveries ranging from 14–34%.

Nanoplastics (NPs; <0.1 μm) are speculated to be a bigger ecological threat due to their predicted wider distribution, higher concentrations, and bioavailability. Primary NPs are manufactured to be that size, while secondary NPs originate from fragmentation of bigger debris. To date, the long-term impact of NPs in freshwater systems, particularly secondary NPs, is not well-understood. Thus, we employed a freshwater invertebrate, Daphnia magna, to investigate the chronic effects of model primary NPs, fluorescent polystyrene nanospheres (PS-NPs; 20 nm), and water leachate of weathered single-use plastics that contained micro-and nanosized particles. In experiment 1, parent Daphnia (F0) were exposed to 1 and 50 mg/L PS-NPs until the production of the neonates (F1) followed by a two-generation recovery. PS-NPs were mainly detected in the intestine and brood chamber in F0 and transferred to F1 and F2. PS-NPs significantly decreased the appendage curling and heartbeat rate in F0 and reduced reproduction in F2. In experiment 2, the plastic leachate also reduced the appendage curling rate but increased growth and reproduction. The results suggest that the acute toxicity of primary and secondary plastic particles is low even at high concentrations, but their chronic and sublethal effects should not be overlooked.

As a result of the burgeoning nanotechnology industry, the number of uses of engineered silver nanoparticles (Ag NPs) in consumer products has risen significantly in recent years.Despite their utility as anti-bacterial agents, the 'nano-scale' properties of these materials may lead to eco-toxicological problems when they end up in the environment. Wastewater effluents represent one of the main routes through which Ag NPs can reach an aquatic environment, where they may potentially interact with aquatic life. However, in wastewaters, Ag NPs may undergo different chemical and physical transformations, which may alter the potential toxicity of these NPs towards aquatic organisms. The main objectives of this study are to characterize the Ag NPs in wastewater effluents and then to assess their interactions with a model organism, the green alga Chlamydomonas reinhardtii.Experiments were conducted to distinguish the effect(s) of the wastewater matrix on the dissolution of Ag NPs and to determine whether the transformed NPs or the dissolved Ag species would be most bioavailable to C. reinhardtii. It was shown that in environmental matrices such as wastewater, the bioavailability of Ag + could be significantly or completely reduced-a Nous avons étudié l'effet de la matrice des eaux usées sur la dissolution des Ag NPs et la biodisponibilité des différentes formes (particulaire et dissoute) des Ag NPs pour C. reinhardtii.Dans les matrices environnementales telles que les eaux usées la biodisponibilité de Ag + serait réduite de façon significative, si ce n'est complète; une conclusion qui va à l'encontre les résultats des études similaires faites dans des matrices biologiques simples. Cette réduction

Wet, cold or freeze-thaw conditions enhanced the release of TiO2 nanoparticles from outdoor painted surfaces.