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Al-Hazmy SM, EL-Ghoul Y, Al-Harby J, Tar H, Alminderej FM. Synthesis, Characterization, and Performance of Pyridomethene-BF2 Fluorescence Dye-Doped PVA Thin Film and PVP Nanofibers as Low γ-ray Dosimeters. ACS OMEGA 2022; 7:34002-34011. [PMID: 36188249 PMCID: PMC9520551 DOI: 10.1021/acsomega.2c03174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 08/09/2022] [Indexed: 06/16/2023]
Abstract
Currently, particular attention is paid to public health related to the field of γ-ray dosimetry, which is becoming increasingly important in medical diagnostic processes. Incorporating sensitive dyes as radiation dose sensors in different material hosts has shown promising radiation dosimetry application routes. In this perspective, the current study proposes a new fluorescent dye based on boron difluoride complex, the pyridomethene-BF2 named 2-(1-(difluoroboraneyl)-1,2-dihydroquinolin-2-yl)-2-(1-methylquinoxalin-2-ylidene) acetonitrile (DBDMA) as an indicator for low γ-ray doses. The different optical and quantum chemical parameters and the spectral behavior of the selected fluorescent dye were first studied. Then, PVP/DBDMA electrospun nanofibers and PVA/DBDMA thin films were prepared. The different UV-vis spectrophotometric and fluorescence studies revealed a clear change after exposure to different γ-ray doses. Thermogravimetric analysis exhibited excellent thermal stability of the prepared nanocomposite films, showing altered thermal behavior after γ-ray treatment. Furthermore, the SEM evaluation displayed a significant modification in the surface morphology of the two designed nanomaterials with increased radiation dose intensity. These novel forms of dosimeter designed in nanoscale composites could therefore constitute a promising and efficient alternative for rapid and accurate detection of low doses of γ-rays in various medical applications.
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Affiliation(s)
- Sadeq M. Al-Hazmy
- Department
of Chemistry, College of Science, Qassim
University, Buraidah 51452, Saudi Arabia
- Department
of Chemistry, College of Science, Sana’a
University, Sana’a 1247, Yemen
| | - Yassine EL-Ghoul
- Department
of Chemistry, College of Science, Qassim
University, Buraidah 51452, Saudi Arabia
- Textile
Engineering Laboratory, University of Monastir, Monastir 5019, Tunisia
| | - Jameelah Al-Harby
- Department
of Chemistry, College of Science, Qassim
University, Buraidah 51452, Saudi Arabia
| | - Haja Tar
- Department
of Chemistry, College of Science, Qassim
University, Buraidah 51452, Saudi Arabia
| | - Fahad M. Alminderej
- Department
of Chemistry, College of Science, Qassim
University, Buraidah 51452, Saudi Arabia
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Al-Hazmy SM, Zouaghi MO, Al-Johani JN, Arfaoui Y, Al-Ashwal R, Hammami B, Alhagri IA, Alhemiary NA, Hamdi N. Chemosensing Properties of Coumarin Derivatives: Promising Agents with Diverse Pharmacological Properties, Docking and DFT Investigation. Molecules 2022; 27:molecules27185921. [PMID: 36144656 PMCID: PMC9503222 DOI: 10.3390/molecules27185921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/02/2022] [Accepted: 09/06/2022] [Indexed: 11/26/2022] Open
Abstract
In this work, a three-component reaction of 3-acetyl-4-hydroxycoumarine, malononitrile, or cyanoacetate in the presence of ammonium acetate was used to form coumarin derivatives. The chemical structures of new compounds were identified by 1H, 13C NMR and an elemental analysis. These compounds were examined in vitro for their antimicrobial activity against a panel of bacterial strains. In addition, these compounds were investigated for antioxidant activities by superoxideradical, DPPH (2,2-Diphenyl-1-picrylhydrazyl), and hydroxyl radical scavenging assays, in which most of them displayed significant antioxidant activities. Furthermore, these compounds were evaluated for anti-inflammatory activity by indirect hemolytic and lipoxygenase inhibition assays and revealed good activity. In addition, screening of the selected compounds 2–4 against colon carcinoma cell lines (HCT-116) and hepatocellular carcinoma cell lines (HepG-2) showed that that 2-amino-4-hydroxy-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)nicotinonitrile 4 exhibited good cytotoxic activity against standard Vinblastine, while the other compounds exhibited moderate cytotoxic activity. Docking simulation showed that2-amino-4-hydroxy-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)nicotinonitrile 4 is an effective inhibitor of the tumor protein HCT-116. A large fluorescence enhancement in a highly acidic medium was observed, and large fluorescence quenching by the addition of traces of Cu2+ and Ni2+ was also remarked.
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Affiliation(s)
- Sadeq M. Al-Hazmy
- Department of Chemistry, College of Science, Qassim University, Buraidah 51452, Saudi Arabia
- Department of Chemistry, College of Science, Sana’a University, Sana’a P.O. Box 1247, Yemen
- Correspondence: (S.M.A.-H.); (J.N.A.-J.); (N.H.)
| | - Mohamed Oussama Zouaghi
- Laboratory of Characterizations, Applications & Modeling of Materials (LR18ES08), Department of Chemistry, Faculty of Sciences, University of Tunis El Manar, Tunis 2092, Tunisia
| | - Jamal N. Al-Johani
- Department of Chemistry, College of Science, Qassim University, Buraidah 51452, Saudi Arabia
- Correspondence: (S.M.A.-H.); (J.N.A.-J.); (N.H.)
| | - Youssef Arfaoui
- Laboratory of Characterizations, Applications & Modeling of Materials (LR18ES08), Department of Chemistry, Faculty of Sciences, University of Tunis El Manar, Tunis 2092, Tunisia
| | - Rania Al-Ashwal
- School of Biomedical Engineering and Health Sciences, Faculty of Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia
- Advanced Diagnostic and Progressive Human Care Research Group, School of Biomedical Engineering and Health Science Teknologi Malaysia, Johor Bahru 81310, Malaysia
| | - Bechir Hammami
- Department of Chemistry, College of Science, Qassim University, Buraidah 51452, Saudi Arabia
| | - Ibrahim A. Alhagri
- Department of Chemistry, College of Science, Qassim University, Buraidah 51452, Saudi Arabia
| | - Nabil A. Alhemiary
- Department of Chemistry, College of Science, Ibb University, Ibb P.O. Box 70270, Yemen
- Department of Chemistry, College of Science and Arts at Sharurah, Najran University, P.O. Box 1988, Najran 11001, Saudi Arabia
| | - Naceur Hamdi
- Department of Chemistry, College of Science and Arts at Ar Rass, Qassim University, P.O. Box 53, Ar Rass 51921, Saudi Arabia
- Research Laboratory of Environmental Sciences and Technologies (LR16ES09), Higher Institute of Environmental Sciences and Technology, University of Carthage, Hammam-Lif 1054, Tunisia
- Correspondence: (S.M.A.-H.); (J.N.A.-J.); (N.H.)
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Santana KVDSD, Oliver SL, Mendes MM, Lanham-New S, Charlton KE, Ribeiro H. Association between vitamin D status and lifestyle factors in Brazilian women: Implications of Sun Exposure Levels, Diet, and Health. EClinicalMedicine 2022; 47:101400. [PMID: 35497056 PMCID: PMC9043392 DOI: 10.1016/j.eclinm.2022.101400] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 03/21/2022] [Accepted: 03/31/2022] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND Vitamin D deficiency has been documented to be prevalent, even in low latitude regions; and this may be related to sun exposure behaviors. The aim of the current study was to assess the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations and lifestyle-related factors in a sample of Brazilian women living at latitude 21º 8' S. METHODS A cross-sectional study was undertaken in 101 women aged 35 years or older in July 2019 to assess the association between 25(OH)D concentration and level of exposure to ultraviolet radiation (UVR), smoking habits, alcohol consumption, and physical activity levels. Age, body mass index (BMI), and postmenopausal status were investigated. FINDINGS According to the slope coefficient for individual daily UVR levels, the concentration of 25(OH)D increased by 5 nmol / L for each extra Standard Erythema Dose of UVR, regardless of age and BMI (p < 0·001). Postmenopausal women had a significantly higher mean concentration of 25(OH)D (p = 0·01), higher UVR exposure (p = 0·01) and lower BMI (p = 0·005) compared with younger women, independent of other confounders including smoking, alcohol, occupation and physical activity. INTERPRETATION Although postmenopausal women from Brazil had higher mean concentrations of 25(OH)D than younger women, more studies are necessary to understand how sun exposure and lifestyle variables interfere with these levels. These findings have important public health implications since they suggest that vitamin D deficiency in older age is not inevitable. FUNDING This study was funded by an award received by Universities Global Partnership Network - UGPN. KVSS and SLO receive scholarship from CAPES, Brazilian Ministry of Education. HR receives a productivity grant from CNPq.
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Affiliation(s)
- Keila Valente de Souza de Santana
- Programa de Pós-Graduação em Saúde Global e Sustentabilidade, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Sofia Lizarralde Oliver
- Departamento de Saúde Ambiental, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Marcela Moraes Mendes
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, Department of Nutritional Sciences, University of Surrey, Guildford, Surrey, United Kingdom
| | - Susan Lanham-New
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, Department of Nutritional Sciences, University of Surrey, Guildford, Surrey, United Kingdom
| | - Karen E Charlton
- School of Medicine, University of Wollongong, Wollongong, Australia NSW and Illawarra Health and Medical Research Institute, Wollongong, Australia NSW
| | - Helena Ribeiro
- Departamento de Saúde Ambiental, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil
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Henning A, J Downs N, Vanos JK. Wearable ultraviolet radiation sensors for research and personal use. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2022; 66:627-640. [PMID: 34743221 DOI: 10.1007/s00484-021-02216-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 10/06/2021] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
Skin cancers are strongly linked to personal exposure to ultraviolet (UV) radiation, yet UV exposure is also the most preventable risk factor. People are exposed to UV rays when they engage in outdoor activities, particularly exercise, which is an important health behavior. Thus, researchers and the general public have shown increasing interest in measuring UV exposure using wearable sensors during outdoor physical activity. However, minimal research exists at the intersection of UV sensors, personal exposure, adaptive behavior due to exposures, and risk of skin damage. Recent years have seen an influx of new consumer-based and research-based UV-sensing technologies with wide-ranging form factors and purposes to fill this research gap, yet a thorough review of available sensors for specific purposes does not exist. Hence, the overall goal of this state-of-the-art review is to synthesize the current academic and gray literature surrounding personal UV-sensing technologies. Peer-reviewed journal articles and "gray literature," such as working papers, manuals, and UV sensor websites, were reviewed, assessing attributes of UV wearables marketed for research use, personal use, or both. Overall, 13 wearable UV sensors are available for personal use and/or research applications. These sensors vary from electronic to photochromic, with large differences in price, data outputs, accuracy, and precision. Recommendations are provided for which sensors are most suitable for various types of research or public use. Notably, the review findings will help guide researchers in future studies assessing UV exposure during physical activity.
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Affiliation(s)
- Alyssa Henning
- School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA
| | - Nathan J Downs
- School of Sciences, University of Southern Queensland, Toowoomba, Qld, Australia
| | - Jennifer K Vanos
- School of Sciences, University of Southern Queensland, Toowoomba, Qld, Australia.
- School of Sustainability, Arizona State University, 800 Cady Mall #108, Tempe, AZ, 85281, USA.
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Alashrah S, El-Ghoul Y, Almutairi FM, Omer MAA. Development, Characterization and Valuable Use of Novel Dosimeter Film Based on PVA Polymer Doped Nitro Blue Tetrazolium Dye and AgNO 3 for the Accurate Detection of Low X-ray Doses. Polymers (Basel) 2021; 13:polym13183140. [PMID: 34578041 PMCID: PMC8473152 DOI: 10.3390/polym13183140] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 09/09/2021] [Accepted: 09/11/2021] [Indexed: 12/26/2022] Open
Abstract
Currently, the uncontrolled exposure of individuals to X-rays during medical examinations represents a substantial danger that threatens both medical professionals and patients. Therefore, radiation dosimetry for low X-ray doses is a very important control of radiation practice in medical diagnostic radiology. In line with this, the current study proposes a valuable dosimeter-based PVA thin film doubly doped with silver nitrate salt and nitro blue tetrazolium dye. The nanocomposite film was prepared via a simple casting method and the different processing parameters were optimized. The performance of radiation detection was evaluated according to optical, chromic, chemical and structural changes after exposure to variable low X-ray doses (0, 2, 4, 10 and 20 mGy). The different film labels exhibited an excellent stability behavior in dark and light upon 30 days of storage. The UV-Vis spectrophotometric study showed a gradual increase in the maximum absorbance as a function of the dose and the corresponding response curve confirmed this linear variation (R = 0.998). A clear structural modification was recorded via X-ray diffraction (XRD) analysis revealing the increase in crystallinity with the level of the dose received by the nanocomposite films. Microscopic surface analysis via SEM assessments revealed a significant morphological change in PVA/Ag+/NBT films exposed to increased radiation doses and typical dendrites growing in needle- or tree-like microstructures appeared with a high X-ray dose. Finally, the nanocomposite films before and after irradiation were evaluated via a spectrocolorimetric study and the different CIELab coordinates, the color difference, as well as the color strength, showed a linear correlation with the intensity of the applied dose. This new dosimeter design could, therefore, provide a promising and efficient alternative for prompt and accurate detection of low X-rays doses in diagnostic radiology.
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Affiliation(s)
- Saleh Alashrah
- Department of Physics, College of Science, Qassim University, Buraidah 51452, Saudi Arabia;
| | - Yassine El-Ghoul
- Department of Chemistry, College of Science, Qassim University, Buraidah 51452, Saudi Arabia
- Textile Engineering Laboratory, University of Monastir, Monastir 5019, Tunisia
- Correspondence:
| | - Faisal Muteb Almutairi
- College of Science, Al-Imam Muhammad Ibn Saud Islamic University, Riyadh 11623, Saudi Arabia;
| | - Mohammed Ahmed Ali Omer
- Department of Radiologic Technology, College of Applied Medical Sciences, Qassim University, Buraidah 51452, Saudi Arabia;
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Bringing Light into Darkness-Comparison of Different Personal Dosimeters for Assessment of Solar Ultraviolet Exposure. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18179071. [PMID: 34501660 PMCID: PMC8431201 DOI: 10.3390/ijerph18179071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 11/23/2022]
Abstract
(1) Measuring personal exposure to solar ultraviolet radiation (UVR) poses a major challenges for researchers. Often, the study design determines the measuring devices that can be used, be it the duration of measurements or size restrictions on different body parts. It is therefore of great importance that measuring devices produce comparable results despite technical differences and modes of operation. Particularly when measurement results from different studies dealing with personal UV exposure are to be compared with each other, the need for intercomparability and intercalibration factors between different measurement systems becomes significant. (2) Three commonly used dosimeter types—(polysulphone film (PSF), biological, and electronic dosimeters)—were selected to perform intercalibration measurements. They differ in measurement principle and sensitivity, measurement accuracy, and susceptibility to inaccuracies. The aim was to derive intercalibration factors for these dosimeter types. (3) While a calibration factor between PSF and electronic dosimeters of about 1.3 could be derived for direct irradiation of the dosimeters, this was not the case for larger angles of incidence of solar radiation with increasing fractions of diffuse irradiation. Electronic dosimeters show small standard deviation across all measurements. For biological dosimeters, no intercalibration factor could be found with respect to PSF and electronic dosimeters. In a use case, the relation between steady-state measurements and personal measurements was studied. On average, persons acquired only a small fraction of the ambient radiation.
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Linde K, Wright CY, du Plessis JL. Personal Solar Ultraviolet Radiation Exposure of Farmworkers: Seasonal and Anatomical Differences Suggest Prevention Measures Are Required. Ann Work Expo Health 2021; 66:41-51. [PMID: 34302333 DOI: 10.1093/annweh/wxab049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 05/31/2021] [Accepted: 06/18/2021] [Indexed: 11/14/2022] Open
Abstract
INTRODUCTION Farmworkers are at risk of excess exposure to solar ultraviolet radiation (UVR) during their work activities, especially if they work in geographical areas with high ambient solar UVR levels such as in South Africa. Excess exposure to solar UVR may lead to several negative health effects such as certain cataracts and skin cancer. This study evaluated personal solar UVR exposure of a group of farmworkers to determine if they were at risk of health-related problems due to excess solar UVR exposure. METHODS Polysulphone film (PSF) badges were placed on the shoulder, arm, and top of the head of outdoor and indoor farmworkers on a macadamia nut and avocado farm in the Limpopo province for the duration of their daily work shift to evaluate their total daily solar UVR exposure. Sixteen days were assessed for each of the three, high solar UVR seasons, i.e. autumn, spring, and summer. RESULTS During autumn, farmworkers' arms received the highest solar UVR exposures (geometric mean (GM) = 7.8 SED, where 1 standard erythemal dose (SED) = 100 J/m2, 95% CI 6.1-9.8 SED) while the highest exposures were on the top of the head during spring (GM = 11.6 SED, 95% CI 7.3-17.4 SED) and summer (GM = 13.9, 95% CI 10.4-17.9 SED). Statistically significant differences in solar UVR exposure were found between the body sites during spring and summer but not autumn. CONCLUSIONS The relatively high daily solar UVR exposure levels of farmworkers suggest this occupational group is at risk of excess solar UVR exposure and preventive measures with awareness information to safeguard health is necessary for employers and employees.
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Affiliation(s)
- Karlien Linde
- Occupational Hygiene and Health Research Initiative (OHHRI), North-West University, Potchefstroom 2520, South Africa.,Department of Physiology and Environmental Health, University of Limpopo, Sovenga 0727, South Africa
| | - Caradee Yael Wright
- Environmental and Health Research Unit, South African Medical Research Council, Pretoria 0002, South Africa.,Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria 0001, South Africa
| | - Johannes Lodewykus du Plessis
- Occupational Hygiene and Health Research Initiative (OHHRI), North-West University, Potchefstroom 2520, South Africa
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Abstract
During leisure time, people can decide if they want to expose themselves to solar ultraviolet (UV) radiation and to what extent. While working, people do not have this choice. Outdoor workers are exposed to solar UV radiation (UVR) on a daily basis. This may pose a certain health risk, which can be estimated when the personal solar UVR exposure (PE) is known. During past decades, a variety of studies were conducted to measure PE of outdoor workers and our knowledge of the PE of outdoor workers has increased remarkably. As shown by this review, studies clearly indicate that PE of most outdoor workers exceeds the internationally proposed threshold limit value, which is comparable to 1.0 to 1.3 standard erythema dose (SED), respectively, to 1.1 to 1.5 UV Index received over one hour. Besides working in a high UVR environ, monotonic workflow (limited movement, nearly static posture) is a risk factor. In such cases, PE can be higher than ambient UVR. In this review, we provide also a list of milestones, depicting the progress and the most important findings in this field during the past 45 years. However, in many respects our knowledge is still rudimentary, for several reasons. Different measuring positions have been used so that measured PE is not comparable. Few studies were designed to enable the extension of measured PE to other locations or dates. Although the importance of a proper calibration of the measuring devices in respect to the changing solar spectrum was pointed out from the beginning, this is often not performed, which leads to high uncertainties in the presented PE levels. At the end of our review, we provide some key points, which can be used to evaluate the quality of a study respectively to support the design of future studies.
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Cheng W, Brown R, Vernez D, Goldberg D. Estimation of Individual Exposure to Erythemal Weighted UVR by Multi-Sensor Measurements and Integral Calculation. SENSORS 2020; 20:s20154068. [PMID: 32707787 PMCID: PMC7435697 DOI: 10.3390/s20154068] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/14/2020] [Accepted: 07/19/2020] [Indexed: 02/07/2023]
Abstract
Ultraviolet radiation (UVR) can be hazardous to humans, especially children, and is associated with sunburn, melanoma, and the risk of skin cancer. Understanding and estimating adults’ and children’s UVR exposure is critical to the design of effective interventions and the production of healthy UVR environments. Currently, there are limitations to the ways computer modeling and field measurements estimate individual UVR exposure in a given landscape. To address these limitations, this study developed an approach of integral calculation using six-directional (up, down, south, north, east, and west) field-measured UVR data and the estimated body exposure ratios (ER) for both children and adults. This approach showed high agreement when compared to a validated approach using ambient UVR and estimated ER data with a high r-square value (90.72% for child and adult models), and a low mean squared error (6.0% for child model and 5.1% for adult model) in an open area. This approach acting as a complementary tool between the climatology level and individual level can be used to estimate individual UVR exposure in a landscape with a complicated shady environment. In addition, measuring daily UVR data from six directions under open sky conditions confirmed that personal dosimeters underestimate actual individual UVR exposure.
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Affiliation(s)
- Wenwen Cheng
- College of Architecture, University of Oklahoma, Norman, OK 73019, USA
- Correspondence:
| | - Robert Brown
- Department of Landscape Architecture and Urban Planning, Texas A&M University, College Station, TX 77843, USA;
| | - David Vernez
- Center for Primary Care and Public Health (Unisanté), Department of Occupational and Environmental Health, University of Lausanne, CH-1015 Lausanne, Switzerland;
| | - Daniel Goldberg
- Department of Geography, Texas A&M University, College Station, TX 77843, USA;
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Use of Electronic UV Dosimeters in Measuring Personal UV Exposures and Public Health Education. ATMOSPHERE 2020. [DOI: 10.3390/atmos11070744] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The performance limits of electronic ultraviolet (EUV) dosimeters, which use AlGaN Schottky photodiodes as the ultraviolet radiation (UVR) sensing element to measure personal erythemally weighted UVR exposures, were investigated via a direct comparison with meteorological-grade reference instruments. EUV dosimeters with two types of AlGaN Schottky photodiode were compared to second-generation ‘Robertson–Berger type’ broadband erythemal radiometers. This comparison was done by calculating correction factors for the deviations of the spectral responsivity of each instrument from the CIE erythemal action spectrum and for deviations in their angular response from the ideal cosine response of flat surfaces and human skin. Correction factors were also calculated to convert the output of these instruments to vitamin D-weighted UV irradiances. These comparisons showed that EUV dosimeters can be engineered with spectral responsivities and cosine response errors approaching those of Robertson–Berger type radiometers, making them very acceptable for use in human UVR exposure and sun safety behaviour studies, provided appropriate side-by-side calibrations are performed. Examples of these calibrations and the effect of EUV dosimeter sampling rates on the calculation of received erythemal UVR doses and erythemal UVR dose rates are provided, as well as brief descriptions of their use in primary skin cancer prevention programmes, handheld meters, and public health displays.
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X-ray Visualization and Quantification Using Fibrous Color Dosimeter Based on Leuco Dye. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10113798] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A polystyrene (PS)-based fibrous color dosimeter, comprising a color former based on 2-(phenylamino)-6-(dipentylamino)-3-methylspiro[9H-xanthene-9,3′-phthalide] (Black305) fluoran leuco dye and a 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine (MBTT) photoacid generator, was developed for visual detection of X-ray doses of 15 Gy and higher. The composite fiber was produced by using a centrifugal spinning method, and the obtained composite fiber exhibited a stable and uniform morphology with a fiber diameter of 10 μm or less and had sufficient mechanical strength. As an example of practical application, we successfully processed the composite fiber into an apron and clearly and visually confirmed that the color change from yellow to black occurs on the surface of the fabric under X-ray exposure.
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