Priority setting for chemicals, waste and pollution: a risk-based strategy for environmental and human health protection.

Chemicals provide numerous benefits that support and improve the health and welfare of humans and the environment in a wide range of applications. The environmental release of chemicals, however, can result in risks to humans and the environment. Minimizing and eliminating chemical pollution should thus represent an important goal for all stakeholders and rights holders.

The number of conspecific alarm substance donors notably influences the behavioural responses of zebrafish subjected to a traumatic stress procedure.

Zebrafish (Danio rerio) represents a complementary pre-clinical model in stress and anxiety research. Conspecific alarm substance (CAS), an alarm pheromone secreted by injured fish, acts as a warning signal and modulates fear responses. Given their schooling nature and that injury precedes CAS release, varying fresh CAS concentrations extracted from different numbers of CAS-donating zebrafish may uniquely influence trauma-related behaviours.

Posttraumatic anxiety-like behaviour in zebrafish is dose-dependently attenuated by the alpha-2A receptor agonist, guanfacine.

Traumatic stress exposure increases noradrenaline (NA) release, which contributes to anxiety and impaired risk-appraisal. Guanfacine, a selective alpha-2A adrenergic receptor agonist, has been used to treat stress-related disorders characterised by impaired prefrontal cortex function. By acting on both presynaptic inhibitory autoreceptors and postsynaptic heteroreceptors, guanfacine attenuates stress reactivity and enhances cognition.

Contingency learning in zebrafish exposed to apomorphine- and levetiracetam.

Cognitive rigidity (CR) refers to inadequate executive adaptation in the face of changing circumstances. Increased CR is associated with a number of psychiatric disorders, for example, obsessive-compulsive disorder, and improving cognitive functioning by targeting CR in these conditions, may be fruitful. Levetiracetam (LEV), clinically used to treat epilepsy, may have pro-cognitive effects by restoring balance to neuronal signalling.

Influence of different functionalized CdTe quantum dots on the accumulation of metals, developmental toxicity and respiration in different development stages of the zebrafish ().

The bioaccumulation and differential effects of cadmium tellurium quantum dot (CdTe QDs) nanomaterials with different functional groups are poorly understood in aquatic organisms. This study aimed to investigate the metal uptake, developmental effects, and respiratory effects of CdTe QDs with different functional groups (COOH, NH3, and PEG) on zebrafish embryos. Zebrafish embryos were exposed to carboxylate (COOH), ammonia (NH3), and polyethylene glycol (PEG) functionalized CdTe QDs at nominal concentrations of 0.

Toxicity assessment of TiO-conjugated Carbon-based nanohybrid material on a freshwater bioindicator cladoceran, Daphnia magna.

The application of nanocomposite materials fabricated from titanium dioxide nanoparticles (TiO NPs) and different carbon (C) allotropes have gained popularity in water treatment applications due to their synergistic properties. Studies to date have focused on simple forms of nanomaterials (NMs), however, with the technology development, there is a dramatic increase in production and application of these complex NMs which could result in toxicological impacts on organisms when released into aquatic environments. This raises serious concerns about their safety and the need to ascertain their potential adverse effects on aquatic organisms.

Toxicity evaluation of TiO/MWCNT-CNF hybrid nanocomposites with enhanced photocatalytic activity toward freshwater microalgae: Pseudokirchneriella subcapitata.

A wide range of semiconductor-assisted photocatalytic nanomaterials (NMs) are currently being considered and investigated as potential photocatalysts in water treatment. The applications of nanocomposites composed of nano-structured titania (nano-TiO) and multi-walled carbon nanotubes (MWCNTs) nanocomposites is growing markedly on account of enhanced photocatalytic efficiency. However, concurrent with the increasing production and application comes a serious concern of these emerging nanosystems about their potential risks in aquatic systems, and thereby potentially threatening aquatic organisms via toxic mechanisms that are, at present, poorly understood.

Environmentally relevant lead (Pb) water concentration induce toxicity in zebrafish (Danio rerio) larvae.

Early developmental stages of aquatic organisms including fish are inherently vulnerable to lead (Pb) and other water metal contaminants. However, reports on the deleterious effects of environmentally relevant Pb levels are limited. To this end, we exposed 2.

Effects of conventionally-treated and ozonated wastewater on mortality, physiology, body length, and behavior of embryonic and larval zebrafish (Danio rerio).

To date, micropollutants from anthropogenic sources cannot be completely removed from effluents of wastewater treatment plants and therefore enter freshwater systems, where they may impose adverse effects on aquatic organisms, for example, on fish. Advanced treatment such as ozonation aims to reduce micropollutants in wastewater effluents and, thus, to mitigate adverse effects on the environment. To investigate the impact and efficiency of ozonation, four different water types were tested: ozonated wastewater (before and after biological treatment), conventionally-treated wastewater, and water from a river (River Ruhr, Germany) upstream of the wastewater treatment plant effluent.

Acute exposure to environmentally relevant lead levels induces oxidative stress and neurobehavioral alterations in larval zebrafish (Danio rerio).

The ubiquitous contamination of environmental lead (Pb) remains a worldwide threat. Improper Pb mine waste disposal from an abandoned lead-zinc mine has recently unearthed widespread Pb poisoning in children in Kabwe Zambia. Although the adverse effects of Pb on human health have begun to receive attention, the ecotoxicological effects on aquatic vertebrates still need further investigation.

Polyethylene glycol (5,000) succinate conjugate of lopinavir and its associated toxicity using Danio rerio as a model organism.

Lopinavir (LPV), a well-known drug administered in human immunodeficiency virus (HIV) infection, has shown limitation for pediatric treatment owing to poor aqueous solubility that gives rise to limited oral bioavailability and short plasma half-life (5-6 h). Polymers such as polyethylene glycol (PEG) have been used as drug carriers to improve their solubility. This study reports the preparation of polyethylene glycol (5,000) succinate (PEG-Suc-LPV) conjugate of LPV by the esterification method.

How toxic is a non-toxic nanomaterial: Behaviour as an indicator of effect in Danio rerio exposed to nanogold.

Gold nanoparticles are used as drug delivery vectors based on the assumption that they have low toxicity. Literature has, however, produced conflicting results over the last few years. As such, this study aimed to investigate the toxicological effects of nanogold (nAu) on several indicators that range from subcellular to whole-organism level.

Assessing predator-prey interactions in a chemically altered aquatic environment: the effects of DDT on Xenopus laevis and Culex sp. larvae interactions and behaviour.

Behavioural assays are used as a tool to understand ecotoxicological effects on organisms, but are often not applied in an ecologically relevant context. Assessment of the effect of chemical contaminants on behaviours relating to fitness and trophic interactions for example, requires incorporating predator-prey interactions to create impact assessments. Dichlorodiphenyltrichloroethane (DDT) is a controlled substance but is still regularly used as a form of mosquito control.

Sublethal Effects of Ionic and Nanogold on the Nematode .

The nematode is used as an ecotoxicological model species in both aqueous medium and solid substrates. It is easy and of low cost to maintain in the laboratory and it produces hundreds of offspring within a short period of time. It also has a small body size (1 mm), making it possible for assays to be conducted in 12-well plates.