Marine nano-ecotoxicology has emerged with the purpose to assess the environmental risks associated with engineered nanomaterials (ENMs) among contaminants of emerging concerns entering the marine environment. ENMs’ massive production and integration in everyday life applications, associated with their peculiar physical chemical features, including high biological reactivity, have imposed a pressing need to shed light on risk for humans and the environment. Environmental safety assessment, known as ecosafety, has thus become mandatory with the perspective to develop a more holistic exposure scenario and understand biological effects. Here, we review the current knowledge on behavior and impact of ENMs which end up in the marine environment. A focus on titanium dioxide (n-TiO₂) and silver nanoparticles (AgNPs), among metal-based ENMs massively used in commercial products, and polymeric NPs as polystyrene (PS), largely adopted as proxy for nanoplastics, is made. ENMs eco-interactions with chemical molecules including (bio)natural ones and anthropogenic pollutants, forming eco- and bio-coronas and link with their uptake and toxicity in marine organisms are discussed. An ecologically based design strategy (eco-design) is proposed to support the development of new ENMs, including those for environmental applications (e.g., nanoremediation), by balancing their effectiveness with no associated risk for marine organisms and humans.

The present study investigates the potential interaction between nano‑titanium dioxide (nano-TiO₂) and the water accommodated fraction (WAF) of crude oil and associated chemicals on bioavailability and biotransformation responses in the European sea bass (Dicentrarchus labrax). An in vivo (48-h) waterborne exposure with nano-TiO₂ (10 mgL^-1), crude oil WAF (0.068 gL^-1), alone and in combination was performed. Combined exposure significantly reduced levels of polycyclic aromatic hydrocarbons (PAH) in either seawater and fish fillets compared to WAF alone. A significant reduction in the expression of several biotransformation genes (cyp1a, gsta, erβ2, elmod2, abcb1 and abcc1) when nano-TiO₂ was combined with WAF was observed in fish liver, compared to WAF alone. EROD and GST enzyme activities were also significantly reduced. Nano-TiO₂ can reduce PAHs bioavailability in seawater and biological responses in European sea bass, suggesting a potential safe application of nano-TiO₂ for the remediation of crude oil WAF in the marine environment.

A topsoil sample obtained from a highly industrialized area (Taranto, Italy) was tested on the DR-CALUX^® cell line and the exposed cells processed with proteomic and bioinformatics analyses. The presence of polyhalogenated compounds in the topsoil extracts was confirmed by GC-MS/MS analysis. Proteomic analysis of the cells exposed to the topsoil extracts identified 43 differential proteins. Enrichment analysis highlighted biological processes, such as the cellular response to a chemical stimulus, stress, and inorganic substances; regulation of translation; regulation of apoptotic process; and the response to organonitrogen compounds in light of particular drugs and compounds, extrapolated by bioinformatics all linked to the identified protein modifications. Our results confirm and reflect the complex epidemiological situation occurring among Taranto inhabitants and underline the need to further investigate the presence and sources of inferred chemicals in soils. The combination of bioassays and proteomics reveals a more complex scenario of chemicals able to affect cellular pathways and leading to toxicities rather than those identified by only bioassays and related chemical analysis. This combined approach turns out to be a promising tool for soil risk assessment and deserves further investigation and developments for soil monitoring and risk assessment.

Sewage sludge applications as soil amendment calls for a proper ecological risk assessment due to unexpected delivery of toxic chemicals and materials. Standardized acute toxicity assays have proven to provide limited information in terms of potential hazard for soil organisms. Here sub-lethal endpoints as physiological and tissue alterations were proposed as suitable tools for sewage sludge ecological risk assessment. Acute toxicity assay using earthworm Eisenia fetida (OECD n.207) was performed on sewage sludge samples from two wastewater treatment plants (A and B) and mortality, body weight, body morphology and histology of intestinal cavity were evaluated at the end of the exposure period. Sewage sludge dilutions (1:50 and 1:100) from plant B caused a low percentage of mortality (5%) while none was observed in worms exposed to plant A. However, all specimens showed external body alterations as vesicles, swellings, constrictions, and discoloration. Histological sections highlight damages to epidermis, circular and longitudinal muscles and chloragogenic tissue regardless of sewage sludge origin. Our findings confirm that standardized end points of acute toxicity are not sensitive enough in worms exposed to sewage sludges while sub-lethal endpoints as body morphology and tissue histology are thus more suitable and appropriate endpoints for assessing potential detrimental outcomes and ecological risk for soil biota.