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The present work is considered to investigate the sources, concentration, and composition of polycyclic aromatic hydrocarbons (PAHs) and associated health risk assessment of road dust in Riyadh City, Saudi Arabia. The study region included an urban area, strongly affected by traffic, a bare and an industrial area. A total of 50 locations were selected for sampling and 16 different PAHs were determined. The concentration of PAHs in road dust and their estimated lifetime average daily dose (LADD) for adults (human) ranged from 0.01 to 126 ng g−1 and 1950 to 16,010 mg kg−1 day−1, respectively. The ADDing was calculated separately for children (>6), teenagers (6−12), and adults (>12) for all PAHs with each collected sample. Moreover, the average daily exposure dose by ingestion (ADDing) and average daily exposure dose by dermal absorption (ADDder) were more in children (<6 years) as compared to teenagers (6−12 years) and adults (>12 years). Likewise, total equivalency factor based on BaP (TEQBaP) calculations pointed out that PAHs having more benzene rings or having high molecular weight showed high TEQBaP as compared to low molecular weight PAHs. The data revealed that the children population is at high risk for asthma, respiratory and cardiovascular diseases, and immunity suppression as compared to adults in the particular area of investigated region. These outcomes of this study can be used to deliver significant policy guidelines concerning habitants of the area for possible measures for controlling PAHs contamination in Riyadh City to protect human health and to ensure environmental sustainability.

The shortage of potable water is a global problem. One of the techniques used to participate solving this problem is the solar distiller. The main demerit of solar distiller is its low output yield. So, this work aims at improving the freshwater productivity of a dish solar distiller by enlarging its absorber surface area and increasing its evaporation rate. As a result, the effect of using three different shapes of absorber liner was investigated: convex dish absorber, stepped absorber, and corrugated surface over the stepped absorber. In addition, the absorber of dish distiller was covered by a cotton wick to enlarge the wetted surface area. Also, different water depths (1.0, 2.0, 3.0, 4.0, and 5.0 cm) in dish distiller with stepped absorber were investigated. Moreover, the distance below basin liner was occupied by energy storing medium (paraffin wax + titanium oxide nanoparticles). The performances of dish distiller, dish distiller with stepped absorber, and dish distiller with corrugated absorber were evaluated and compared to that of a conventional solar distiller. Experimental results revealed that the performance of dish distiller with corrugated absorber, wick, and energy storing material was higher than that of dish distiller with stepped absorber, which was better than that of dish distiller, which was higher than that of conventional distiller. As well, the highest improvement in productivity of dish distiller with stepped absorber was 125% compared to conventional distiller and took place at 2-cm water depth. In addition, the productivity of dish distiller with corrugated absorber and wick was improved by 160% compared to that of conventional distiller. Additionally, the highest performance was obtained for dish distiller with corrugated absorber, wick, and energy storing material, where the productivity was augmented by about 183%, and the thermal efficiency reached 69.5%., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Maghemite (Fe 2 O 3 -NPs) nanoparticles were synthesized by a convenient, green and cost effective method using aqueous fruit extracts of Hyphaene thebaica. Different techniques like FTIR, XRD, UV-Vis, Raman, HR-TEM, EDS. SAED, Zeta potential were used to establish the nature of Fe 2 O 3 -NPs, while the therapeutic properties were studied using different biological assays including antiviral, antibacterial, antifungal, antioxidant and enzyme inhibition assays. XRD pattern revealed sharp peaks and a crystalline nature of Fe 2 O 3 -NPs. HR-TEM revealed quasi-spherical and cuboidal morphologies, while the particle size in ~10 nm. FTIR indicated a sharp peak centered at ~444 cm -1 which is the characteristic FeO band vibration. SAED pattern indicated the crystalline nature while EDS also confirmed the synthesis of Fe 2 O 3 NPs. Zeta potential was obtained in different solvents and physiological buffers indicating highest value in water (-26.5 mV) and lowest in DMSO (-15.8 mV). Tested bacterial strains, Bacillus subtilis was found to be inhibited significantly. Aspergillus flavus appeared to be susceptible to all of the tested concentration of Fe 2 O 3 NPs. Maximum 40.78% FRSA was obtained at 400 μg/mL. Cell culture based studies on RD cells and L20B cells indicated reduction in viability of cells with increase concentration of Fe 2 O 3 NPs. Moderate inhibition of polio virus-1 and polio virus-2 was observed, after culturing the virus in the L20B cells. Excellent Protein Kinase (PK) inhibition was revealed. Hemolytic potential and cytotoxic potential was indicated to be dose dependent. In conclusion, the present report for the first time reports the synthesis of Fe 2 O 3 NPs from H. thebaica fruits and reveals their biomedical potential including antiviral potential., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Aim: The biosynthesis of chromium oxide nanoparticles (Cr 2 O 3 NPs), using Hyphaene thebaica as a bioreductant, for assessment of their potential nanomedicinal applications. Materials & methods: Biosynthesized Cr 2 O 3 NPs were characterized by x-ray diffraction, Fourier-transform infrared spectroscopy, energy dispersive x-ray spectroscopy, scanning and transmission electron microscopy, selected area electron diffraction, UV-Vis spectroscopy and ζ-potential measurement. In vitro assays were used to assess the biological properties of Cr 2 O 3 NPs. Results: Nanoparticles with size approximately 25-38 nm were obtained with a characteristic Cr-O vibration at 417 cm -1 . A broad spectrum antimicrobial potential and antioxidant nature is reported. Slight inhibition of polio virus and biocompatibility at low doses was observed. Conclusion: We conclude a multifunctional nature of biogenic Cr 2 O 3 NPs.

Biosynthesis of bismuth vanadate (BiVO 4 ) nanorods was performed using dried fruit extracts of Hyphaene thebaica as a cost effective reducing and stabilizing agent. XRD, DRS, FTIR, zeta potential, Raman, HR-SEM, HR-TEM, EDS and SAED were used to study the main physical properties while the biological properties were established by performing diverse assays. The zeta potential is reported as - 5.21 mV. FTIR indicated Bi-O and V-O vibrations at 640 cm -1 and 700 cm -1 /1120 cm -1 . Characteristic Raman modes were observed at 166 cm -1 , 325 cm -1 and 787 cm -1 . High resolution scanning and transmission electron micrographs revealed a rod like morphology of the BiVO 4 . Bacillus subtilis, Klebsiella pneumonia, Fusarium solani indicated highest susceptibility to the different doses of BiVO 4 nanorods. Significant protein kinase inhibition is reported for BiVO 4 nanorods which suggests their potential anticancer properties. The nanorods revealed good DPPH free radical scavenging potential (48%) at 400 µg/mL while total antioxidant capacity of 59.8 µg AAE/mg was revealed at 400 µg/mL. No antiviral activity is reported on sabin like polio virus. Overall excellent biological properties are reported. We have shown that green synthesis can replace well established processes for synthesizing BiVO 4 nanorods.