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El-Hiti GA, Ahmed DS, Yousif E, Al-Khazrajy OSA, Abdallh M, Alanazi SA. Modifications of Polymers through the Addition of Ultraviolet Absorbers to Reduce the Aging Effect of Accelerated and Natural Irradiation. Polymers (Basel) 2021; 14:20. [PMID: 35012042 PMCID: PMC8747282 DOI: 10.3390/polym14010020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022] Open
Abstract
The photooxidative degradation process of plastics caused by ultraviolet irradiation leads to bond breaking, crosslinking, the elimination of volatiles, formation of free radicals, and decreases in weight and molecular weight. Photodegradation deteriorates both the mechanical and physical properties of plastics and affects their predicted life use, in particular for applications in harsh environments. Plastics have many benefits, while on the other hand, they have numerous disadvantages, such as photodegradation and photooxidation in harsh environments and the release of toxic substances due to the leaching of some components, which have a negative effect on living organisms. Therefore, attention is paid to the design and use of safe, plastic, ultraviolet stabilizers that do not pose a danger to the environment if released. Plastic ultraviolet photostabilizers act as efficient light screeners (absorbers or pigments), excited-state deactivators (quenchers), hydroperoxide decomposers, and radical scavengers. Ultraviolet absorbers are cheap to produce, can be used in low concentrations, mix well with polymers to produce a homogenous matrix, and do not alter the color of polymers. Recently, polyphosphates, Schiff bases, and organometallic complexes were synthesized and used as potential ultraviolet absorbers for polymeric materials. They reduced the damage caused by accelerated and natural ultraviolet aging, which was confirmed by inspecting the surface morphology of irradiated polymeric films. For example, atomic force microscopy revealed that the roughness factor of polymers' irradiated surfaces was improved significantly in the presence of ultraviolet absorbers. In addition, the investigation of the surface of irradiated polymers using scanning electron microscopy showed a high degree of homogeneity and the appearance of pores that were different in size and shape. The current work surveys for the first time the use of newly synthesized, ultraviolet absorbers as additives to enhance the photostability of polymeric materials and, in particular, polyvinyl chloride and polystyrene, based mainly on our own recent work in the field.
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Affiliation(s)
- Gamal A. El-Hiti
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11433, Saudi Arabia;
| | - Dina S. Ahmed
- Department of Medical Instrumentation Engineering, Al-Mansour University College, Baghdad 64021, Iraq;
| | - Emad Yousif
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq; (E.Y.); (M.A.)
| | - Omar S. A. Al-Khazrajy
- Department of Chemistry, College of Education for Pure Science (Ibn Al-Haytham), University of Baghdad, Baghdad 64021, Iraq;
| | - Mustafa Abdallh
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq; (E.Y.); (M.A.)
| | - Saud A. Alanazi
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, P.O. Box 10219, Riyadh 11433, Saudi Arabia;
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Al-Khazrajy OSA, Abdallh M. Sorption and degradation of ranitidine in soil: Leaching potential assessment. Chemosphere 2020; 259:127495. [PMID: 32623203 DOI: 10.1016/j.chemosphere.2020.127495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/08/2020] [Accepted: 06/21/2020] [Indexed: 06/11/2023]
Abstract
Pharmaceuticals have been categorized as emerging contaminants that may be hazardous to the environment. To assess their environmental risk, understanding their fate and behaviour is highly needed, particularly in soil where little is known. This study investigated sorption, degradation and mobility potential of ranitidine (RAN) from soil to groundwater in two soils with different physicochemical properties. Sorption resulted in data were found to fit well to isotherm models following the order: linear model > Freundlich > Langmuir with R2 of up to 0.98. RAN showed low sorption affinity to soils with maximum adsorption coefficient (Kd) of 21.47 L kg-1. Physicochemical properties for soil and RAN showed insignificant positive correlation to Kd values except the sand%, which showed significant negative correlation. Degradation of RAN was fitted to the first order exponential decay model with minimum DT50 (time for a 50% dissipation in RAN concentration) values of 31.6 d under non-sterile conditions. Prolonged DT50 of 62.4 d was obtained in soils from sterile treatments indicating the microbial activity role in dissipation of RAN process. To predict potential leaching of RAN in soil, this study experimentally obtained values of Kd, Koc and DT50 were implemented in mathematical screening models. Results showed different but moderate leaching potential of RAN in soils.
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Affiliation(s)
- Omar S A Al-Khazrajy
- Department of Chemistry, College of Education for Pure Science (Ibn al-Haitham), University of Baghdad, Baghdad, Iraq.
| | - Mustafa Abdallh
- Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq
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Mohd Firdaus MA, Agatz A, Hodson ME, Al-Khazrajy OSA, Boxall ABA. Fate, uptake, and distribution of nanoencapsulated pesticides in soil-earthworm systems and implications for environmental risk assessment. Environ Toxicol Chem 2018; 37:1420-1429. [PMID: 29341233 DOI: 10.1002/etc.4094] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/07/2017] [Accepted: 01/11/2018] [Indexed: 06/07/2023]
Abstract
Nanopesticides are novel plant protection products offering numerous benefits. Because nanoparticles behave differently from dissolved chemicals, the environmental risks of these materials could differ from conventional pesticides. We used soil-earthworm systems to compare the fate and uptake of analytical-grade bifenthrin to that of bifenthrin in traditional and nanoencapsulated formulations. Apparent sorption coefficients for bifenthrin were up to 3.8 times lower in the nano treatments than in the non-nano treatments, whereas dissipation half-lives of the nano treatments were up to 2 times longer. Earthworms in the nano treatments accumulated approximately 50% more bifenthrin than those in the non-nano treatments. In the non-nano treatments, most of the accumulated material was found in the earthworm tissue, whereas in the nano treatments, the majority resided in the gut. Evaluation of toxicokinetic modeling approaches showed that models incorporating the release rate of bifenthrin from the nanocapsule and distribution within the earthworm provided the best estimations of uptake from the nano-formulations. Overall, our findings indicate that the risks of nanopesticides may be different from those of conventional formulations. The modeling presented provides a starting point for assessing risks of these materials but needs to be further developed to better consider the behavior of the nanoencapsulated pesticide within the gut system. Environ Toxicol Chem 2018;37:1420-1429. © 2018 SETAC.
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Affiliation(s)
- Mohd Anuar Mohd Firdaus
- Environment Department, Wentworth Way, University of York, Heslington, York, United Kingdom
- Department of Land Management, Faculty of Agriculture, UPM Serdang, Selangor Darul Ehsan, Malaysia
| | - Annika Agatz
- Environment Department, Wentworth Way, University of York, Heslington, York, United Kingdom
| | - Mark E Hodson
- Environment Department, Wentworth Way, University of York, Heslington, York, United Kingdom
| | - Omar S A Al-Khazrajy
- Environment Department, Wentworth Way, University of York, Heslington, York, United Kingdom
- Department of Chemistry, College of Ibn al-Haitham, University of Baghdad, Baghdad, Iraq
| | - Alistair B A Boxall
- Environment Department, Wentworth Way, University of York, Heslington, York, United Kingdom
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Al-Khazrajy OSA, Bergström E, Boxall ABA. Factors affecting the dissipation of pharmaceuticals in freshwater sediments. Environ Toxicol Chem 2018; 37:829-838. [PMID: 29068472 DOI: 10.1002/etc.4015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/08/2017] [Accepted: 10/17/2017] [Indexed: 06/07/2023]
Abstract
Degradation is one of the key processes governing the impact of pharmaceuticals in the aquatic environment. Most studies on the degradation of pharmaceuticals have focused on soil and sludge, with fewer exploring persistence in aquatic sediments. We investigated the dissipation of 6 pharmaceuticals from different therapeutic classes in a range of sediment types. Dissipation of each pharmaceutical was found to follow first-order exponential decay. Half-lives in the sediments ranged from 9.5 (atenolol) to 78.8 (amitriptyline) d. Under sterile conditions, the persistence of pharmaceuticals was considerably longer. Stepwise multiple linear regression analysis was performed to explore the relationships between half-lives of the pharmaceuticals, sediment physicochemical properties, and sorption coefficients for the compounds. Sediment clay, silt, and organic carbon content and microbial activity were the predominant factors related to the degradation rates of diltiazem, cimetidine, and ranitidine. Regression analysis failed to highlight a key property which may be responsible for observed differences in the degradation of the other pharmaceuticals. The present results suggest that the degradation rate of pharmaceuticals in sediments is determined by different factors and processes and does not exclusively depend on a single sediment parameter. Environ Toxicol Chem 2018;37:829-838. © 2017 SETAC.
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Affiliation(s)
- Omar S A Al-Khazrajy
- Environment Department, University of York, Heslington, York, UK
- Department of Chemistry, College of Ibn al-Haitham, University of Baghdad, Baghdad, Iraq
| | - Ed Bergström
- Centre of Excellence in Mass Spectrometry and Department of Chemistry, University of York, Heslington, York, UK
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Al-Khazrajy OSA, Boxall ABA. Impacts of compound properties and sediment characteristics on the sorption behaviour of pharmaceuticals in aquatic systems. J Hazard Mater 2016; 317:198-209. [PMID: 27270139 DOI: 10.1016/j.jhazmat.2016.05.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/29/2016] [Accepted: 05/20/2016] [Indexed: 05/13/2023]
Abstract
Sorption is a key factor in determining the persistence, attenuation and bioavailability of sediment-associated contaminants. However, our understanding of the sorption behaviour of pharmaceuticals in sediments is poor. In this study, we investigated the sorption behaviour of a diverse set of pharmaceuticals in a range sediment types. Sorption affinity of pharmaceuticals for all sediments was found to increase in the order mefenamic acid<cimetidine<atenolol<amitriptyline<diltiazem. Comparison of the experimental observations with predictions from an existing model for estimating sorption revealed the model worked poorly for the study pharmaceuticals. Multiple linear regression analysis was therefore used to develop new models for estimating sorption of individual pharmaceuticals based on sediment properties. The analyses indicated that sorption is related to properties such as Log Dow of a compound in the sediment (lipophilicity corrected for the sediment pH), cation exchange capacity, clay%, organic carbon content and exchangeable Ca(2+), although, with the exception of atenolol, robust relationships between sediment properties and sorption were not obtained. Overall, the results demonstrate how complex the processes are that drive the sorption of pharmaceuticals in sediments and highlight the need for generation of further experimental data and further model development work.
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Affiliation(s)
- Omar S A Al-Khazrajy
- Environment Department, University of York, Heslington, Wentworth Way, York, YO10 5NG, UK
| | - Alistair B A Boxall
- Environment Department, University of York, Heslington, Wentworth Way, York, YO10 5NG, UK.
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Al-Khazrajy OSA, Boxall ABA. Risk-based prioritization of pharmaceuticals in the natural environment in Iraq. Environ Sci Pollut Res Int 2016; 23:15712-26. [PMID: 27137195 PMCID: PMC4956694 DOI: 10.1007/s11356-016-6679-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/10/2016] [Indexed: 05/05/2023]
Abstract
Numerous studies have demonstrated the occurrence of pharmaceuticals in the natural environment, raising concerns about their impact on non-target organisms or human health. One region where little is known about the exposure and effects of pharmaceuticals in the environment is Iraq. Due to the high number of pharmaceuticals used by the public health sector in Iraq (hospitals and care centres) and distributed over the counter, there is a need for a systematic approach for identifying substances that should be monitored in the environment in Iraq and assessed in terms of environmental risk. In this study, a risk-based prioritization approach was applied to 99 of the most dispensed pharmaceuticals in three Iraqi cities, Baghdad, Mosul and Basrah. Initially, information on the amounts of pharmaceuticals used in Iraq was obtained. The top used medicines were found to be paracetamol, amoxicillin and metformin with total annual consumption exceeding 1000 tonnes per year. Predicted environmental concentrations (PECs) and predicted no-effect concentrations (PNECs), derived from ecotoxicological end-points and effects related to the therapeutic mode of action, were then used to rank the pharmaceuticals in terms of risks to different environmental compartments. Active pharmaceutical ingredients used as antibiotics, antidepressants and analgesics were identified as the highest priority in surface water, sediment and the terrestrial environment. Antibiotics were also prioritized according to their susceptibility to kill or inhibit the growth of bacteria or to accelerate the evolution and dissemination of antibiotic-resistant genes in water. Future work will focus on understanding the occurrence, fate and effects of some of highly prioritized substances in the environment.
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Affiliation(s)
- Omar S A Al-Khazrajy
- Environment Department, University of York, Heslington, Wentworth Way, York, YO10 5NG, UK
| | - Alistair B A Boxall
- Environment Department, University of York, Heslington, Wentworth Way, York, YO10 5NG, UK.
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