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Urbanization and population are increasing significantly across the world resulting in increase in vegetarian food demand and hence exposure to pesticides and pollutants. This study aimed at monitoring and assessing the levels of three groups of toxicants including organophosphate pesticides (OPPs), other selective pesticides used in Saudi Arabia (SPs) and polychlorinated biphenyl (PCBs). The study included 69 samples of 23 different species of fruit and vegetables consumed in Asir region, Saudi Arabia. After extraction, clean-up and pre-concentration, the analytes were separated and quantified by ultra-performance liquid chromatography equipped with photodiode detector. The ranges of limits of detection (LOD, gg/ml) were as follows: OPPs 0.008-0.147, SAPs 0.006-0.619 and PCBs 0.002-0.007. Many toxicants were found < LOD. For OPPs, butachlor, metachlor and prometon were detected in few species. Simazine and atrazine were detected in the majority of samples (45-6000 gg/kg). For SPs, abamectin was also detected in the majority of samples (12.18-441.0 gg/kg). Emamectin, profenofos and cypermethrin were detected in few samples. For PCBs, PCB 110, PCB 138 and PCB 180 were detected in few samples. The potential exposure to cancerous and non-cancerous diseases for adults and children from consumption of fruit and vegetables were estimated in terms of estimated daily intake (EDI), hazard quotient (HQ), hazard index (HI) and lifetime cancer risk (LCR). HQ and HI values of detected OPPs, SAPs and PCBs were < 1 indicating no significant risk, with the exception of the cancer and non-cancer HQ for adults and children from emamectin in some samples, besides HI non-cancer and cancer of SAPs for adults from some samples. Additionally, atrazine, PCB 101, PCB 180, and PCB 153 recorded safe LCR levels (1x10-4 - 1x10-6), with the exception of PCB 138 in arugula. [ABSTRACT FROM AUTHOR]

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were studied in the Nile Delta area of Egypt's southern Mediterranean for their environmental impacts, probable sources, and ecological risk assessment. Using the Gas Chromatography Triple Quadrupole technique, the residues of 16 OCPs and 18 PCBs were determined. The total OCPs content in the seawater and sediment samples ranged from 0.108 to 10.97 μg/L and 0.301 to 5.268 ng/g, respectively, while the PCBs residues had values between 0.808 and 1069.75 μg/L in seawater and between not detected and 575.50 ng/g in sediment samples. The findings of the risk evaluation showed that, except for endosulfan-I, OCPs caused little harm in seawater. However, PCB180, PCB153, PCB156, PCB126 and PCB138 posed a comparatively significant risk. The concentration of DDTs was higher than the effect range low and threshold effect level but remained below the effect range median and probable effect level, posing a minimal ecological concern. • First PCBs and OCPs study in water–sediment of Nile Delta, southern Mediterranean • Residues of 16 OCPs and 18 PCBs were determined from seawater and sediment samples. • Except for endosulfan-I, OCPs caused little harm in seawater. • PCB180, PCB153, PCB156, PCB126 and PCB138 posed ecological risk concern. [ABSTRACT FROM AUTHOR]

This research studies the inhibition efficiency (IE) of chitosan biguanidine hydrochloride (CBGHCl), as novel environmentally - friendly organic inhibitor, contrary to the corrosion of low carbon steel (LCS) in 0.5 M sulphuric acid whether the synergistic effect of 0.1 M NaCl exists or not. Results obtained from both electrochemical impedance spectroscopy (EIS) and electrochemical polarization measurements indicated a significant increase in the corrosion protection of the low carbon steel in the presence of CBG-HCl and 0.1 M NaCl as opposed to the presence of CBG-HCl alone. The formation of a protective film by the adsorbed inhibitor blend obstructs the surface area of the LCS rod hindering corrosive gradients to react with the metal surface. The research showed that an IE of 80% was reached when 100 ppm of CBG-HCI was added along with 0.1 M NaCl whereas it only reached 66% in the absence of 0.1 M NaCl. A maximum IE of 92.67% was reported for 100 ppm CBG-HCl and 0.1 M NaCl after six hours of immersion. Furthermore, potentiodynamic experiments indicate that a CBG-HCl and 0.1 M NaCl blend acts as a mixed-type inhibitor for the corrosion of low carbon steel. Inhibition efficiency of CBG-HCl/0.1 M NaCl blend remains noticeably high with long periods of immersion indicating its good stability in the applied acidic medium. [ABSTRACT FROM AUTHOR]

This manuscript reports the contents of selected metals in street dust from functional areas in Khamees-Mushait city, Saudi Arabia. The metals were quantified using inductively-coupled plasmamass spectrometry. Acceptable recovery (87.2- 109.3%) was obtained using spiking and certified reference material approaches. The metal contents (μg/g) recorded the following ranges: As 3.42- 44.76, Se 2.64-38.25, Sr 4 14.56-3692.93, Ce 0.04- 0.42 and U 1.25-19.70. The principal component analysis extracted one significant component. Significant correlations (r > 0.9) were obtained for AsSe, As-U, Se-U and Sr-Ce. The cluster analysis classified sampling sites into two main clusters; one of them was represented by one site. The GIS mapping revealed heterogeneous spatial distribution with hot spots in the centers of the east side of the study area. The geo-accumulation index classified the study area at low hazardous level while the enrichment factor classified the study area at levels from minimal to moderate pollution. As reported possible adverse health effect on children while no adverse health effects were observed from As on adult and from Sr and U on both children and adult. On the other hand, As reported a non-carcinogenic risk for both children and adult. [ABSTRACT FROM AUTHOR]

Numerous malignancies have been shown to be successfully treated with Curcumin. Despite its promising effects, Curcumin has limitations in clinical studies because of its stability, low water solubility, and adsorption. Carbon quantum dots with high biocompatibility can be employed as nanostructured material carriers to enhance Curcumin availability. In this study, folic acid was used as the raw material for the hydrothermal preparation of carbon dots, followed by the loading of Curcumin onto the carbon dots to form a folic acid carbon dot/Curcumin nanocomposite. The morphology and the chemical structure of the synthesized carbon dots were investigated. Folic acid carbon dots displayed robust emission peaks with a quantum yield of 41.8%. Moreover, the adsorption effectiveness of Curcumin on carbon dots was determined to be 83.11%. The liberating pattern of Curcumin was pH-dependent and reached 36 and 27% after a few hours at pH 5 and 7.4, respectively. The release occurs via the Fickiann diffusion mechanism with ah n value less than 0.45.The nanocomposite was tested for antibacterial activity against gram-negative Pseudomonas aeruginosa ATCC 27,853 and gram-positive Staphylococcus aureus ATCC 25,923. The nanocomposite displayed antibacterial behavior with MIC 12.5 µg/mL. The anticancer activities of the nanocomposite were further tested against high-folate receptor-expressing Hela cells (cervical malignancy) and low-folate receptor-expressing HepG2 cells (hepatocellular carcinoma). Folic acid carbon dot/Curcumin nanocomposite reduced Hela cell viability at an IC50 of 88.723 ± 0.534 g/mL. On the other hand, HepG2 cells showed no toxicity response. Highlights: Hydrothermal preparation of carbon dots (CDs) using folic acid as a Curcumin loading. The synthesis of amorphous carbon dots had an average particle size of 6.8 ± 2.1 nm. CDs loaded with Curcumin are active against gram-positive and gram-negative bacteria. Anticancer properties of CDs against a high folate receptor-expressing Hela cells. The anticancer properties of CDs against a low folate receptor-expressing HepG2. [ABSTRACT FROM AUTHOR]

An efficient method for the generation of cellulose di- and tri-acetate nano-structures is obtained through testing ferric chloride hydrate (FeCl3·6H2O) as a valuable Lewis acid catalyst with acetic anhydride under microwave irradiation. Our target was to evaluate the effects of the reaction conditions on the products' properties such as surface area and particle size distribution. It was found that changes in the degree of substitution (DS), the surface area, the degree of polymerization and the particle size distribution of the products correlated with reaction conditions. Cellulose tri-acetate nanofibers with DS of 2.94 with 98.03% yield was prepared using 200 mg of FeCl3·6H2O, 25 ml of Ac2O and 4 minutes of microwave irradiation. Also, cellulose di-acetate nanofibers were prepared with DS values ranged between 2.37 and 2.72 with yield ranged between 78.92 and 90.58%. The percentage of acetyl groups (Ac%) as well as the BET specific surface area, total pore volume, mean pore diameter, mono layer volume and the mean particle size of the products were determined. The maximum specific surface area obtained for the acetylated cellulose was about ten times larger than that measured for the commercial cotton cellulose and about six times larger than that of the commercial cellulose acetate. The lowest mean particle size (34.90 nm) was about eleven times smaller than the mean particle size of the commercial cellulose acetate (394 nm). The present work has proved that FeCl3·6H2O was a highly active catalyst for the esterification of cellulose with unexpected yields and for the formation of nanofibers with low molecular weight. [ABSTRACT FROM AUTHOR]

This paper examines the possibility of applying ozone (O 3 ) and O 3 combined with ultraviolet (UV) to degrade the content of synthetic wastewater Mordant Violet 40 dye (MV-40). The experimental parameters included pH, initial dye concentration and time of reaction; all were assessed in a batch reactor to achieve the optimum operating circumstances. The results obtained showed that the pH and initial MV-40 dye concentration controlled the decolorization process. The maximum decolorization of MV-40 dye solution was obtained at pH 9. More than 98% of color removal was obtained within 20 min for both UV assisted O 3 and individual O 3 treatment of 100 ppm dye concentration. Kinetic analyses showed that the decolorization of MV-40 dye followed the second-order kinetics. The degree of decolorization of MV-40 dye solution was indirectly proportional to the initial dye concentration. Gas Chromatography Mass Spectrum analysis of treated synthetic dye solution was performed at the end of the pre-treatment time to the final degradation products of MV-40 dye. The obtained results explained that the advanced oxidation processes enhanced the biodegradability and lowered the zooplankton toxicity of the treated MV-40 dye solution. [ABSTRACT FROM AUTHOR]

This work tests the viability of applying ozone (O 3 ) and O 3 combined with ultraviolet (UV) to degrade the content of synthetic wastewater containing Direct Blue 86 (DB-86) dye. The tested parameters, which included pH, initial concentration of DB-86 dye and time of reaction, were tested in a batch reactor to achieve optimum operating circumstances. The results obtained in this study showed that pH and initial concentration of DB-86 dye controlled the efficiency of the decolorization process. The maximum decolorization was obtained at pH 11. More than 98% of color removal was reported after 35 min of O 3 treatment (for 100 ppm dye concentration). Kinetic analyses showed that color removal of DB-86 dye followed first-order kinetics. The rate of color removal was primarily relative to the initial DB-86 dye concentration. The effect of seawater on the efficiency of the process was studied. Gas Chromatography Mass Spectrum analysis of treated synthetic DB-86 dye solution was performed at the end of the pre-treatment time to study the final degradation products of DB-86 dye. The obtained results revealed that ozonation processes had reduced the zooplankton toxicity belonging to the raw solution and had improved the biodegradability of the DB-86 dye wastewater. [ABSTRACT FROM AUTHOR]