Early detection of cyanide, organophosphate and rodenticide pollution based on locomotor activity of zebrafish larvae

Cyanide, organophosphate and rodenticides are highly toxic substances widely used in agriculture and industry. These toxicants are neuro- and organotoxic to mammals at low concentrations, thus early detection of these chemicals in the aqueous environment is of utmost importance. Here, we employed the behavioral toxicity test with wildtype zebrafish larvae to determine sublethal concentrations of the above mentioned common environmental pollutants. After optimizing the test with cyanide, nine rodenticides and an organophosphate were successfully tested. The compounds dose-dependently initially (0–60-min exposure) stimulated locomotor activity of larvae but induced toxicity and reduced swimming during 60–120-min exposure. IC50 values calculated based on swimming distance after 2-h exposure, were between 0.1 and 10 mg/L for both first-generation and second-generation anticoagulant rodenticides. Three behavioral characteristics, including total distance travelled, sinuosity and burst count, were quantitatively analyzed and compared by hierarchical clustering of the effects measured by each three parameters. The toxicity results for all three behavioral endpoints were consistent, suggesting that the directly measured parameter of cumulative swimming distance could be used as a promising biomarker for the aquatic contamination. The optimized method herein showed the potential for utilization as part of a monitoring system and an ideal tool for the risk assessment of drinking water in the military and public safety.

E-Waste Reporting in Malaysia – A Preliminary Study

Globally, the awareness of environmental sustainability is gaining prominence, and one of the critical issues discussed in this area is waste management. With the advent of the digitalisation age, where information may be retrieved with a finger point, the use of electric and electronic appliances has been increasing exponentially. The appliances contain components that are usually filled with toxic materials and heavy metals such as mercury, lead and brominated flame retardants that are considered hazardous under the Basel Convention. When these appliances reach the end of their useful life, the toxic components that are not properly disposed of will eventually end up in landfills, thus endangering human health and the environment (www.doe.gov.my). Unproperly managed e-waste will result in soil, atmospheric and aquatic contamination (Alabi, Adeoluwa, Huo, Xu, & Bakare, 2021). Furthermore, these contaminations posed a threat to human, animals and plants (Alabi et al., 2021). Within humans, exposure to e-waste will lead to health problems such as changes in thyroid function, respiratory problems, changes in temperament and behaviour, decreased lung function, DNA damage and cancer (Grant et al., 2013; Alabi et al., 2021). Keywords: E-waste, Reporting, Annual reports, Malaysia

Microplastics in Aquatic Environments: Sources, Ecotoxicity, Detection & Remediation

Microplastic pollutants are increasingly posing a significant threat of aquatic contamination and causing various adverse effects on the aquatic environment as well as human health. Microplastics are hazardous chemicals to marine and freshwater ecosystems; therefore, it is becoming a severe concern for ecology. Microplastics can also expose via drinking water and can be vulnerable to all living organisms. Microplastics work as carriers for various toxic components such as additives and other hazardous substances from industrial and urbanized areas. These microplastic contaminated effluents are ultimately transferred into water systems and directly ingested by organisms associated with a particular ecosystem. The microplastics components also pose an indirect threat to aquatic ecosystems by adsorbing surrounding other water pollutants. Due to the luxuriant discharge of billion tons of plastic waste from domestic to industrial level every year, degraded microplastics get accumulated in various aquatic systems, contaminate, and introduce into the food chain. This review mainly focuses on occurrence, factors influencing the release of microplastics into aquatic ecosystems, possible impact of these toxic micro-sized particles on human health and aquatic life. This study also briefly discusses removing microplastics from effluent and water systems using different advanced final-stage treatment technologies.

Assessment of Human Pharmaceuticals in Drinking Water Catchments, Tap and Drinking Fountain Waters

The occurrence of pharmaceuticals in water catchments and drinking waters raises potential risks to public health. Therefore, after addressing the major aquatic contamination pathway, the wastewater treatment plants (WWTPs), and, subsequently, surface waters, 18 human pharmaceuticals from 6 therapeutic groups (antibiotics, lipid regulators, selective serotonin reuptake inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs) and hormones) were analyzed in drinking water catchments, tap and drinking fountain waters. This was performed by solid phase extraction (SPE) and liquid chromatography coupled with tandem mass detection (LC-MS/MS). The 97 samples analyzed were collected from 31 different sites in the center of Portugal. All samples presented concentrations below the method detection limits (MDLs) that ranged between 1.13 to 5.45 ng L−1. The achieved results contributed to a better knowledge on the Portuguese and European context of drinking water, since there is a knowledge gap regarding this matrix. Comparing our data with other studies, published worldwide, we can observe that median concentrations of pharmaceuticals were reported in the low ng L−1 levels, values close to our MDLs. Consequently, it is unlikely that, in light of the current knowledge, the presence of pharmaceuticals in drinking water presents a threat to human health.

Environmental Contamination and Human Exposure to Select Endocrine-Disrupting Chemicals: A Review

Endocrine-disrupting compounds (EDCs) are exogenous compounds that interfere with the normal hormone functions and ultimately lead to health disorders. Parabens, phenols, and phthalates are well-known EDCs, produced globally in large quantities and widely used in a variety of applications. Several studies have monitored these compounds in a variety of environmental matrices, including air, water, sediment, fish, human tissues, soil, indoor dust, and biosolids, etc. In recent years, environmental contamination and human exposure to these chemicals have become a great concern, due to their residue levels exceeding the permissible/acceptable limits. In this review, we focus on the origin of these EDCs, aquatic contamination pathways, distribution, human exposure, health implications, and healthcare costs. Further, this review identifies critical challenges and future research needs in removing or minimizing environmental contamination and exposure to these chemicals to protect living resources.

On the Development of Selective Chelators for Cadmium: Synthesis, Structure and Chelating Properties of 3-((5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)amino)benzo[d]isothiazole 1,1-dioxide, a Novel Thiadiazolyl Saccharinate

Aquatic contamination by heavy metals is a major concern for the serious negative consequences it has for plants, animals, and humans. Among the most toxic metals, Cd(II) stands out since selective and truly efficient methodologies for its removal are not known. We report a novel multidentate chelating agent comprising the heterocycles thiadiazole and benzisothiazole. 3-((5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)amino)benzo[d]isothiazole 1,1-dioxide (AL14) was synthesized from cheap saccharin and characterized by different techniques, including single crystal X-ray crystallography. Our studies revealed the efficiency and selectivity of AL14 for the chelation of dissolved Cd(II) (as compared to Cu(II) and Fe(II)). Different spectral changes were observed upon the addition of Cd(II) and Cu(II) during UV-Vis titrations, suggesting different complexation interactions with both metals.

A graphene-based hydrogel monolith with tailored surface chemistry for PFAS passive sampling

Aquatic contamination by per- and polyfluorinated alkyl substances (PFAS) has attracted global attention due to their environmental and health concerns. Current health advisories and surface water regulatory limits require PFAS...

Tetracycline Photocatalytic Degradation under CdS Treatment

Industrialization and the growing consumption of medicines leads to global aquatic contamination. One of the antibiotics widely used against bacterial infections in both human and veterinary medicine is tetracycline. Despite its positive antibiotic action, tetracycline is resistant against degradation, and therefore it accumulates in the environment, including the aquatic environment, creating great health hazards, possibly stimulating antibiotic resistance of pathogenic organisms. In this research, aqueous suspensions of semiconductor nanoparticles CdS were used for photocatalytic activity studies in the presence of methylene blue as a model compound, and finally, in the presence of tetracycline, a broad-spectrum antibiotic widely used against bacterial infections, as well as a live-stock food additive. The mechanism and kinetic rate constants of photocatalytic degradation processes of methylene blue and tetracycline were described in correlation with the energy diagram of CdS nanoparticles.