1,800 research outputs found

    Rising Level of Public Exposure to Mobile Phones: Accumulation through Additivity and Reflectivity

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    A dramatic development occurring in our daily life is the increasing use of mobile equipment including mobile phones and wireless access to the Internet. They enable us to access several types of information more easily than in the past. Simultaneously, the density of mobile users is rapidly increasing. When hundreds of mobile phones emit radiation, their total power is found to be comparable to that of a microwave oven or a satellite broadcasting station. Thus, the question arises: what is the public exposure level in an area with many sources of electromagnetic wave emission? We show that this level can reach the reference level for general public exposure (ICNIRP Guideline) in daily life. This is caused by the fundamental properties of electromagnetic field, namely, reflection and additivity. The level of exposure is found to be much higher than that estimated by the conventional framework of analysis that assumes that the level rapidly decreases with the inverse square distance between the source and the affected person. A simple formula for the exposure level is derived by applying energetics to the electromagnetic field. The formula reveals a potential risk of intensive exposure.Comment: 5 pages, 1 fugure; to appear in J. Phys. Soc. Jpn. Vol.71 No.2 in Feb 200

    Numerically simulated exposure of children and adults to pulsed gradient fields in MRI

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    PurposeTo determine exposure to gradient switching fields of adults and children in a magnetic resonance imaging (MRI) scanner by evaluating internal electric fields within realistic models of adult male, adult female, and child inside transverse and longitudinal gradient coils, and to compare these results with compliance guidelines. Materials and MethodsPatients inside x-, y-, and z-gradient coils were simulated using anatomically realistic models of adult male, adult female, and child. The induced electric fields were computed for 1 kHz sinusoidal current with a magnitude of 1 A in the gradient coils. Rheobase electric fields were then calculated and compared to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) 2004 and International Electrotechnical Commission (IEC) 2010 guidelines. The effect of the human body, coil type, and skin conductivity on the induced electric field was also investigated. ResultsThe internal electric fields are within the first level controlled operating mode of the guidelines and range from 2.7V m(-1) to 4.5V m(-1), except for the adult male inside the y-gradient coil (induced field reaches 5.4V m(-1)).The induced electric field is sensitive to the coil type (electric field in the skin of adult male: 4V m(-1), 4.6V m(-1), and 3.8V m(-1) for x-, y-, and z-gradient coils, respectively), the human body model (electric field in the skin inside y-gradient coil: 4.6V m(-1), 4.2V m(-1), and 3V m(-1) for adult male, adult female, and child, respectively), and the skin conductivity (electric field 2.35-4.29% higher for 0.1S m(-1) skin conductivity compared to 0.2S m(-1)). ConclusionThe y-gradient coil induced the largest fields in the patients. The highest levels of internal electric fields occurred for the adult male model. J. Magn. Reson. Imaging 2016;44:1360-1367

    Determinants of fluoroscopy time for invasive coronary angiography and percutaneous coronary intervention: Insights from the NCDR ®

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    Objectives Identifying the distributions and determinants of fluoroscopy time for invasive coronary angiography (ICA) and percutaneous coronary intervention (PCI). Background ICA and PCI are significant contributors to radiation exposure from medical imaging in the US. Fluoroscopy time is a potentially modifiable determinant of radiation exposure for these procedures, but has not been well characterized in contemporary practice. Methods We evaluated the distribution of fluoroscopy time in patients undergoing ICA and/or PCI in the CathPCI Registry ® , stratifying patients by numerous clinical scenarios. Hierarchical models were used to determine patient, procedure, operator and hospital‐level factors associated with fluoroscopy time for these procedures. Results Our study included a total of 3,295,348 ICA and PCI procedures performed by 9,600 operators from January 2005 through June 2009. There was wide variation in fluoroscopy times for these procedures with median [IQR] fluoroscopy times of 2.6 [1.7–4.5] minutes for ICA, 6.7 [4.2–10.8] minutes for ICA in patients with prior coronary artery bypass grafting (CABG), 10.1 [6.0–17.4] minutes for PCI, 10.7 [7.0–16.9] minutes for PCI with ICA, and 16.0 [10.6–24.0] minutes for PCI and ICA in patients with prior CABG. Prolonged fluoroscopy times (>30 minutes) were rare for ICA, but occurred in 6.7% of PCIs and 14.7% of PCIs in patients with prior CABG. After accounting for patient characteristics and procedure complexity, operator and hospital‐level factors explained nearly 20% of the variation in fluoroscopy time. Conclusions Fluoroscopy times vary widely during ICA and PCI with operator and hospital‐level factors contributing substantially to these differences. A better understanding of potentially modifiable sources of this variation will elucidate opportunities for enhancing the radiation safety of these procedures. © 2013 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101860/1/ccd24996.pd

    Основные направления и перспективы изучения имиджа науки в современном обществе

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    Ставится проблема имиджа науки, понимаемого как совокупность содержатель-и эмоционально-оценочных представлений о существенных компонентах науки. Обосновываются основные направления исследования и формирования имиджа науки. Выделяются и анализируются виды имиджа науки в современном российском обществе.Поставлено проблему іміджу науки, який розуміється як сукупність змістових і емоційно-оціночних уявлень щодо існуючих компонентів науки. Обґрунтовано основні напрями досліджень і формування іміджу науки. Виокремлено і проаналізовано види іміджу науки в сучасному російському суспільстві.The author puts the problem of the image of science, considered as a combination of visions on the existing components of science, based on knowledge, emotions and judgments. The main areas of research related with the image of science are justified, with distinguishing and analyzing the types of vision on science within the Russian society

    Principles for non-ionizing radiation protection

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    In this statement, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) presents its principles for protection against adverse health effects from exposure to non-ionizing radiation. These are based upon the principles for protection against ionizing radiation of the International Commission for Radiological Protection (ICRP) in order to come to a comprehensive and consistent system of protection throughout the entire electromagnetic spectrum. The statement further contains information about ICNIRP and the processes it uses in setting exposure guidelines

    Light-Emitting Diodes (LEDS): implications for safety

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    Since the original ICNIRP Statement was published in 2000, there have been significant improvements in the efficiency and radiance (i.e., optical radiation emission) of LEDs. The most important improvement is the development of 'white' LEDs that can be used as general lighting sources, which are more efficient than traditional lighting sources. LEDs emitting in the ultraviolet wavelength region have also become available and have made their way into consumer products. All these changes have led to a rise in concern for the safety of the optical radiation emissions from LEDs. Several in vitro and animal studies have been conducted, which indicate that blue and white LEDs can potentially cause retinal cell damage under high irradiance and lengthy exposure conditions. However, these studies cannot be directly extrapolated to normal exposure conditions for humans, and equivalent effects can also be caused by the optical radiation from other light sources under extreme exposure conditions. Acute damage to the human retina from typical exposure to blue or white LEDs has not been demonstrated. Concern for potential long-term effects, e.g. age-related macular degeneration (AMD), remains based on epidemiological studies indicating a link between high levels of exposure to sunlight and AMD. When evaluating the optical radiation safety of LEDs, it has now been established that published safety standards for lamps, not lasers, should be applied. Thus far, the only clear, acute adverse health effects from LEDs are those due to temporal light modulation (including flicker). Glare can also create visual disturbances when LED light fixtures are not properly designed. Further research is needed on potential health effects from short- and long-term exposure to new and emerging lighting technologies

    Guidelines for limiting exposure to electromagnetic fields (100 kHz to 300 GHz)

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    Radiofrequency electromagnetic fields (EMFs) are used to enable a number of modern devices, including mobile telecommunications infrastructure and phones, Wi-Fi, and Bluetooth. As radiofrequency EMFs at sufficiently high power levels can adversely affect health, ICNIRP published Guidelines in 1998 for human exposure to time-varying EMFs up to 300 GHz, which included the radiofrequency EMF spectrum. Since that time, there has been a considerable body of science further addressing the relation between radiofrequency EMFs and adverse health outcomes, as well as significant developments in the technologies that use radiofrequency EMFs. Accordingly, ICNIRP has updated the radiofrequency EMF part of the 1998 Guidelines. This document presents these revised Guidelines, which provide protection for humans from exposure to EMFs from 100 kHz to 300 GHz

    Intended human exposure to non-ionizing radiation for cosmetic purposes

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    Cosmetic devices using non-ionizing radiation (NIR) are increasingly available for people who wish to modify their appearance for aesthetic purposes. There are a wide range of NIR modalities used for cosmetic procedures, including devices that use optical radiation (laser, intense pulsed light, and light-emitting diode), electromagnetic fields, and ultrasound. Common procedures involving the application of NIR include epilation, skin rejuvenation, body sculpting and contouring, treatment of vascular and skin lesions, tattoo removal, and scar reduction. The majority of research on the use of NIR cosmetic devices has focused on the efficacy of the treatment rather than adverse effects or complications. Studies that assessed safety consisted mostly of case reports and small case series. Common adverse effects on the skin reported include mild and transient pain, erythema, swelling, and changes in pigmentation. Less common, more severe side effects include burns, blisters, scarring, persisting erythema, altered pigmentation, and eye damage. Some of the latter may have resulted from treatment errors. Particular groups of people that may be at greater risk from optical radiation include people with dark skin, with high sun exposure, and taking photosensitizing medications or supplements. There is lack of evidence for the safety profile of cosmetic NIR procedures during pregnancy. Reports of injuries to workers administering treatments with cosmetic NIR devices are rare, but inadvertent damage to the eye from optical devices may occur. Randomized controlled trials are required to fully assess potential adverse effects from the use of NIR cosmetic devices. Regulation varies worldwide and some regions apply the same safety classification and guidance as for medical devices. In order to reduce harm associated with the use of cosmetic devices, ICNIRP considers it important that regulations that cover all types and frequencies of cosmetic NIR devices are adopted worldwide and that there is greater oversight regarding their use

    Comments on the 2013 ICNIRP laser guidelines

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    A description of ICNIRP's independent, best practice system of guidance on the protection of people and the environment from exposure to non-ionizing radiation

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    ABSTRACT: In this statement, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) presents its structure, its activities, and general approach to providing guidance on NIR protection. The statement highlights ICNIRP's independence and presents the principle and requirements of no commercial or other vested interests. ICNIRP's funding arrangements and collaboration with other advisory bodies and radiation protection authorities are also described. The statement also presents the types of guidance documents that are produced by ICNIRP and the general approach in assessing scientific evidence
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