Review of the 1st Watch List under the Water Framework Directive and recommendations for the 2nd Watch List

The surface water Watch List (WL) under the Water Framework Directive (WFD) is a mechanism for obtaining high-quality Union-wide monitoring data on potential water pollutants for the purpose of determining the risk they pose and thus whether Environmental Quality Standards (EQS) should be set for them at EU level. According to the EQS Directive (article 8b) , this list should be updated every 2 years. The main objectives of this report are: • To present an overview of the data gathered during the 1st year of monitoring of the 1st WL (also called WL dataset in this report), • To assess whether this WL dataset is sufficient to determine the risk posed by the WL substances, and consequently to determine whether any of these substances can be taken out of the WL, • To propose new substance(s) to be included in the second WL, using the information and results from the latest review of the list of priority substances, as well as any other relevant information available at the time of this report. The executive summary first explains the context for the assessment. Then, mirroring the report itself, it presents an overview of the WL dataset for the different WL substances, it specifies the criteria for taking substances out of the WL and the substances proposed on the basis of these criteria, and finally it presents the criteria for including new substances in the WL and the new proposed WL candidates.JRC.D.2-Water and Marine Resource

Modes of action of the current Priority Substances list under the Water Framework Directive and other substances of interest

The Water Framework Directive 2000/60/EC (WFD) has established a strategy for water protection that includes specific measures for pollution control to achieve good chemical and ecological status at European level. There is a need to review the approach to the current listing of priority substances (PS) under the WFD and to the current assessment of the chemical status, and consider eventually a wider range of chemical substances that could be covered in future monitoring programmes. Overall, the aim is to assess the water status more holistically and understand which the real effects are caused by the sum of the chemical substances present in the aquatic environment (including emerging pollutants /other substances of interest, metabolites and transformation products). The assessment of chemical status should be improved and linked with ecological status where relevant. Hundreds of different substances may co-occur, and even if most are present at very small concentrations they could exert a toxic effect on aquatic organisms (Carvalho et al. 2014) exposed for their entire life cycle and indirectly on human health (via food and drinking water consumption). Some of the substances in the current list of Priority Substances and in the first Watch List are considered in groups (e.g. brominated diphenylethers, neonicotinoid insecticides), but the overall approach to chemical pollution is otherwise based on the regulation of single substances. It has become increasingly clear that the risks from the vast number of chemical substances present in the environment cannot be adequately controlled on this basis. The Commission acknowledges the need to consider the potential toxic effects of mixtures of chemicals (EC COM(2012)252, 7th EAP). The challenge is to find a way of capturing a true picture of the chemical status of water bodies based on standards and methods that assess the presence of an adequate range of representative chemical effect types or modes of action (MoA), for example. The knowledge on the MoA is an important driver for linking exposure to chemicals to their effects in the aquatic environment, and therefore for development and application of the scientific methodologies for the assessment of combined effects of chemicals - the effect-based methods (EBM). The EBM, including biomarkers and bioassays, can target different levels of biological organisation in the aquatic environment, such as individual and/or sub-organism, community, and population levels (Carvalho et al. 2014, Ann-Sofie Wernersson et al. 2014). It is however much less clear how these EBM can be used to capture (predictively) the indirect effects that might occur in humans following long-term chronic exposure to pollutants via the aquatic environment. The use of effect-based monitoring approaches, complementary to chemical analysis, could allow assessing chemical status more holistically (rather than with a limited but ever-growing list of individual substances). The use of the EBM offers also the advantage of overcoming analytical difficulties (Kunz et al. 2015) and reducing monitoring costs by screening. To become a credible complement to chemical monitoring information, however, a better understanding of the capabilities and gaps of available EBM is needed. This report, based on a comprehensive literature study, reviews the current PS list and other substances of interest, considering their MoA(s). The review of data from the open sources clearly identified few groups of toxicological endpoints, with the majority driven by non-specific mechanisms (e.g. oxidative stress, activation of metabolizing / detoxifying pathways, histopathology, and others), and few groups with more specific biochemical / physiological pathways (photosynthesis inhibition, acetylcholinesterase inhibition, presence of PAHs metabolites, expression of metallothioneins). The majority of current PS and other substances of interest can be grouped, based on few common toxicological endpoints, and biomarkers are available for determining the concentrations and/or effects of some groups of substances. The identified biomarkers of effect seem to be however in general not very specific. There is clearly no “one size fits all” bioassay / EBM that could provide the toxicological potency of every PS and other substances of interest and their mixture toward all aquatic organisms in all water bodies, but rather a battery of bioassays that should be selected as “fit for purpose”. In addition, the present report allowed identification of uncertainty and inconsistency in observations, and thus identified areas where future investigations can be best directed. The present knowledge about MoA(s) remains limited, especially for the emerging substances of concern, such as pyrethroids and neonicotinoides.JRC.D.2-Water and Marine Resource

The Surfactant Dipalmitoylphophatidylcholine (DPPC) Modifies Acute Responses in Alveolar Carcinoma Cells in Response to Low Dose Silver Nanoparticle Exposure

Nanotechnology is a rapidly growing field with silver nanoparticles (AgNP) in particular utilized in a wide variety of consumer products. This has presented a number of concerns relating to exposure and the associated toxicity to humans and the environment. As inhalation is the most common exposure route, this study investigates the potential toxicity of AgNP to A549 alveolar epithelial carcinoma cells and the influence of a major component of lung surfactant dipalmitoylphosphatidylcholine (DPPC) on toxicity. It was illustrated that exposure to AgNP generated low levels of oxidative stress and a reduction in cell viability. While DPPC produced no significant effect on viability studies its presence resulted in increased reactive oxygen species formation. DPPC also significantly modified the inflammatory response generated by AgNP exposure. These findings suggest a possible interaction between AgNP and DPPC causing particles to become more reactive, thus increasing oxidative insult and inflammatory response within A549 cell

In vivo cholinesterase sensitivity of gilthead seabream (Sparus aurata) exposed to organophosphate compounds: Influence of biological factors

Two cholinesterases have been found in vertebrates, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). These enzymes are present in the gilthead seabream, AChE in the brain and muscle and BChE in the muscle. Cholinesterases have been used as biomarker of effect in environmental monitoring studies. However, there are few studies about the influence of biometric parameters on ChE. This paper studies the possible influence of biological factors on brain and muscle cholinesterase (ChE) in Sparus aurata. Our results show that ChE activity in brain and muscle tissues changes depending on several biological variables. ChE activity in these tissues decreased when the age (48-152 week), body length (14.15-28.95 cm) and body weight (42.73-380.74 g) of the fishes studied increased. The relationships between brain and muscle ChE activity and several biometric factors were curvilinear

Adsorption at cell surface and cellular uptake of silica nanoparticles with different surface chemical functionalizations: impact on cytotoxicity

International audienceSilica nanoparticles are particularly interesting for medical applications because of the high inertness and chemical stability of silica material. However, at the nanoscale their innocuousness must be carefully verified before clinical use. The aim of this study was to investigate the in vitro biological toxicity of silica nanoparticles depending on their surface chemical functionalization. To that purpose, three kinds of 50 nm fluorescent silica-based nanoparticles were synthesized: 1) sterically stabilized silica nanoparticles coated with neutral polyethylene glycol (PEG) molecules, 2) positively charged silica nanoparticles coated with amine groups and 3) negatively charged silica nanoparticles coated with carboxylic acid groups. RAW 264.7 murine macrophages were incubated for 20 hours with each kind of nanoparticles. Their cellular uptake and adsorption at the cell membrane were assessed by a fluorimetric assay and cellular responses were evaluated in terms of cytotoxicity, pro-inflammatory factor production and oxidative stress. Results showed that the highly positive charged nanoparticle, were the most adsorbed at cell surface and triggered more cytotoxicity than other nanoparticles types. To conclude, this study clearly demonstrated that silica nanoparticles surface functionalization represents a key parameter in their cellular uptake and biological toxicity

Phytochemical-loaded mesoporous silica nanoparticles for nose-to-brain olfactory drug delivery

Central nervous system (CNS) drug delivery is often hampered due to the insidious nature of the blood-brain barrier (BBB). Nose-to-brain delivery via olfactory pathways have become a target of attention for drug delivery due to bypassing of the BBB. The antioxidant properties of phytochemicals make them promising as CNS active agents but possess poor water solubility and limited BBB penetration. The primary aim of this study was the development of mesoporous silica nanoparticles (MSNs) loaded with the poorly water-soluble phytochemicals curcumin and chrysin which could be utilised for nose-to-brain delivery. We formulated spherical MSNP using a templating approach resulting in ∼220nm particles with a high surface porosity. Curcumin and chrysin were successfully loaded into MSNP and confirmed through Fourier transformation infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and HPLC approaches with a loading of 11-14% for curcumin and chrysin. Release was pH dependant with curcumin demonstrating increased chemical stability at a lower pH (5.5) with a release of 53.2%±2.2% over 24h and 9.4±0.6% for chrysin. MSNP were demonstrated to be non-toxic to olfactory neuroblastoma cells OBGF400, with chrysin (100μM) demonstrating a decrease in cell viability to 58.2±8.5% and curcumin an IC50 of 33±0.18μM. Furthermore confocal microscopy demonstrated nanoparticles of <500nm were able to accumulate within cells with FITC-loaded MSNP showing membrane localised and cytoplasmic accumulation following a 2h incubation. MSNP are useful carriers for poorly soluble phytochemicals and provide a novel vehicle to target and deliver drugs into the CNS and bypass the BBB through olfactory drug delivery

(Q)SAR Modelling of Nanomaterial Toxicity - A Critical Review

There is an increasing recognition that nanomaterials pose a risk to human health, and that the novel engineered nanomaterials (ENMs) in the nanotechnology industry and their increasing industrial usage poses the most immediate problem for hazard assessment, as many of them remain untested. The large number of materials and their variants (different sizes and coatings for instance) that require testing and ethical pressure towards non-animal testing means that expensive animal bioassay is precluded, and the use of (quantitative) structure activity relationships ((Q)SAR) models as an alternative source of hazard information should be explored. (Q)SAR modelling can be applied to fill the critical knowledge gaps by making the best use of existing data, prioritize physicochemical parameters driving toxicity, and provide practical solutions to the risk assessment problems caused by the diversity of ENMs. This paper covers the core components required for successful application of (Q)SAR technologies to ENMs toxicity prediction, and summarizes the published nano-(Q)SAR studies and outlines the challenges ahead for nano-(Q)SAR modelling. It provides a critical review of (1) the present status of the availability of ENMs characterization/toxicity data, (2) the characterization of nanostructures that meets the need of (Q)SAR analysis, (3) the summary of published nano-(Q)SAR studies and their limitations, (4) the in silico tools for (Q)SAR screening of nanotoxicity and (5) the prospective directions for the development of nano-(Q)SAR models

Silica nanoparticles induce lung inflammation in mice via ROS/PARP/TRPM2 signaling-mediated lysosome impairment and autophagy dysfunction

Background Wide applications of nanoparticles (NPs) have raised increasing concerns about safety to humans. Oxidative stress and inflammation are extensively investigated as mechanisms for NPs-induced toxicity. Autophagy and lysosomal dysfunction are emerging molecular mechanisms. Inhalation is one of the main pathways of exposing humans to NPs, which has been reported to induce severe pulmonary inflammation. However, the underlying mechanisms and, more specifically, the interplays of above-mentioned mechanisms in NPs-induced pulmonary inflammation are still largely obscure. Considered that NPs exposure in modern society is often unavoidable, it is highly desirable to develop effective strategies that could help to prevent nanomaterials-induced pulmonary inflammation. Results Pulmonary inflammation induced by intratracheal instillation of silica nanoparticles (SiNPs) in C57BL/6 mice was prevented by PJ34, a poly (ADP-ribose) polymerase (PARP) inhibitor. In human lung bronchial epithelial (BEAS-2B) cells, exposure to SiNPs reduced cell viability, and induced ROS generation, impairment in lysosome function and autophagic flux. Inhibition of ROS generation, PARP and TRPM2 channel suppressed SiNPs-induced lysosome impairment and autophagy dysfunction and consequent inflammatory responses. Consistently, SiNPs-induced pulmonary inflammation was prevented in TRPM2 deficient mice. Conclusion The ROS/PARP/TRPM2 signaling is critical in SiNPs-induced pulmonary inflammation, providing novel mechanistic insights into NPs-induced lung injury. Our study identifies TRPM2 channel as a new target for the development of preventive and therapeutic strategies to mitigate nanomaterials-induced lung inflammation