Silver nanoparticles (AgNPs) are widely used in commercial applications as antimicrobial agents, but there have recently been increasing concerns raised about their possible environmental and health impacts. In this study, zebrafish embryos were exposed to two sizes of AgNP, 4 and 10 nm, through a continuous exposure from 4 to 96 h post-fertilisation (hpf), to study their uptake, impact and molecular defense responses. Results showed that zebrafish embryos were significantly impacted by 72 hpf when continuously exposed to 4 nm AgNPs. At concentrations above 0.963 mg/L, significant in vivo uptake and delayed yolk sac absorption was evident; at 1.925 mg/L, significantly reduced body length was recorded compared to control embryos. Additionally, 4 nm AgNP treatment at the same concentration resulted in significantly upregulated hypoxia inducible factor 4 (HIF4) and peroxisomal membrane protein 2 (Pxmp2) mRNA expression in exposed embryos 96 hpf. In contrast, no significant differences in terms of larvae body length, yolk sac absorption or gene expression levels were observed following exposure to 10 nm AgNPs. These results demonstrated that S4 AgNPs are available for uptake, inducing developmental (measured as body length and yolk sac area) and transcriptional (specifically HIF4 and Pxmp2) perturbations in developing embryos. This study suggests the importance of particle size as one possible factor in determining the developmental toxicity of AgNPs in fish embryos.

Nanotechnology is often described as an emerging technology, holding promise for a diverse range of fields. Public awareness may have a strong impact on public acceptance of nano-technology and its various implications. In Jordan, nano-education has only been introduced recently into universities and it is offered to students of pharmacy, engineering, biomedical sciences, and agriculture. However, there is no data available on nanotechnology awareness among the public in Jordan. Therefore, we conducted this study to evaluate Jordanian public awareness and concern about nanotechnology, nanomaterials, and nanoproducts and its implications for health related applications of nanotechnology. An online survey was developed consisting of 15 questions and separated into three domains. The study findings show that more than half of the respondents have a very low awareness with regards to nanotechnology and its various implications. Additionally, respondents show interest to learn more about nanotechnology and its implications, preferring several sources of information such as media, universities and research institutions.

We investigated the effects of short-term exposure of bare TiO₂NPs and polyelectrolyte-coated TiO₂NPs in the 5–25 nm size range, at relatively high concentrations (of 500 and 1000 mg/L) under light or dark conditions, in D. rerio embryos. The biological endpoints investigated included embryo viability and mRNA transcript levels of antioxidant and membrane transport genes relative to control embryos. The presence of nanoparticles on the surface of embryos was assessed using TEM. The results confirm an accumulation of TiO₂NPs on the outer surface (chorion) of the embryo, but not within the embryo. No significant difference in embryo viability was detected following each exposure regime. The expression of antioxidant biomarker, SOD2, was significantly impacted by the type of TiO₂NP, with TiO₂NPs/PSS/PAH coating exposure showing down regulation; the concentration of the nanoparticles, with down regulation at 500 mg/L; and dark/light condition with down regulation in the light. The expression levels of the hypoxia and membrane markers, HIF1 and Pxmp2, were not significantly impacted by any factor. The study indicates that SOD2 mRNA expression levels may be useful in the detection of apparent oxidative stress induced by the titania nanoparticle build up on the embryo chorion surface.

As Jordan advances in an attempt to promote greywater reuse, it is important to investigate the composition of bacteria in these new sources. To evaluate the presence of enteric pathogens in greywater, a pilot study investigating enteric pathogens in household washing machines and kitchen sink effluents from residential premises was conducted. In the culture-dependent method, bacteria were identified after using Sanger sequencing of 16S rRNA. Bacteria in the phylum Proteobacteria have been found to be the most abundant phyla, which may indicate that they play an important environmental role and might be representative of adaptation to different environments. Klebsiella sp. and Pseudomonas sp. were the two major genera found in this study and accounted for 78.57% of the total isolates. This is the first investigation of enteric pathogens in household washing machines and kitchen sink effluents in Jordan. To my knowledge, no study has identified the microbial hazards associated with greywater reuse in Jordan yet. Additional research with more adequate methodology is needed to assist our findings.

Sponges (Porifera) are the largest biomass component of coral reefs benthic fauna among marine organisms and are very morphologically diverse. In the present work, we aimed to identify marine sponges in the Jordanian Gulf of Aqaba using the partial 18S rRNA and the 28S rRNA genes as DNA barcoding markers. A total of nine morphologically different marine sponge samples from 6.6m to approximately 22m depth were collected. Sponge fragments were frozen at −80 °C prior to DNA extraction. The sponge's DNA was extracted using a commercial kit and subjected directly to PCR amplification for the 18S rRNA and 28S rRNA genes. The DNA sequences were analyzed using the Basic Local Alignment Search Tool (BLAST) to determine the sponge's identity, and phylogenetic trees were constructed to clarify the relationship among the samples. The results obtained revealed the presence of the following genera: Axinella, Negombata, Siphonochalina, Diacarnus, and an unidentified genus within the order Haplosclerida. Identification of sponge species was difficult due to the scarcity of diagnostic morphological characters. To our knowledge, this is the first study in the Jordanian Gulf of Aqaba that focuses on the morphological and molecular taxonomy of marine sponges using DNA barcoding markers.