Richard Tell - Academia.edu (original) (raw)

Papers by Richard Tell

Magnetic fields emanate from radial tires due to the presence of reinforcing belts which are made... more Magnetic fields emanate from radial tires due to the presence of reinforcing belts which are made of magnetized steel wire. When these tires spin, they generate alternating magnetic fields of extremely low frequency (ELF), usually below 20 Hz. The fundamental frequency of these fields is determined by tire rotation rate and has a sinusoidal waveform with a high harmonic content. The static field of radial tires can exceed 500mT at the tread, and the tire-generated alternating fields can exceed 2.0 mT at seat level in the passenger compartment of vehicles. Degaussing the tires reduces both the static and alternating fields to low levels, but the fields increase gradually over time after degaussing. The tire-generated fields are below the frequencies detected by most of the magnetic field meters used in previous studies of power frequency magnetic field health effects. If these fields are biologically active, failure to detect them could compromise exposure assessments associated with...

Health physics, 1991

As the use of video display terminals (VDTs) has expanded, questions have been raised as to wheth... more As the use of video display terminals (VDTs) has expanded, questions have been raised as to whether working at a VDT affects the risk of adverse pregnancy outcome. A particular focus for these questions has been the very low frequency (VLF) magnetic field produced by a VDT's horizontal deflection coil. VDTs also produce VLF electric fields, extremely low frequency (ELF) electric and magnetic fields, and static electric fields, Ten studies of pregnancy outcome in VDT operators have been conducted in six countries, and with one exception, none has concluded that magnetic fields from VDTs may predispose pregnant operators to spontaneous abortion or congenital malformation. The epidemiologic studies conducted thus far do not provide a basis for concluding that VDT work and adverse pregnancy outcome are associated. Studies of fetal resorptions and malformations in rodents exposed to VLF magnetic fields have produced inconsistent findings. Two laboratories in Sweden that studied mice ...

1979 IEEE International Symposium on Electromagnetic Compatibility, 1979

The U.S. Environmental Protection Agency has been collecting broadcast signal field intensity dat... more The U.S. Environmental Protection Agency has been collecting broadcast signal field intensity data for over three years to estimate population exposure to this form of nonionizing radiation. Measurement data have been obtained at 486 locations distributed throughout 15 large cities and collectively represent approximately 14,000 measurements of VHF and UHF signal field intensities. The VHF and UHF broadcast service is the main source of ambient radiofrequency exposure in the United States. A computer algorithm has been developed which uses these measurement data to estimate the broadcast exposure at some 47,000 census enumeration districts within the metropolitan boundaries of these 15 cities. The results of the computations provide information on the fraction of the population that is potentially exposed to various intensities of radiofrequency radiation. Special emphasis has been placed on determining the uncertainty inherent to the exposure estimation procedure and details are pr...

IEEE Access, 2019

The newly released IEEE Std C95.1 TM-2019 defines exposure criteria and associated limits for the... more The newly released IEEE Std C95.1 TM-2019 defines exposure criteria and associated limits for the protection of persons against established adverse health effects from exposures to electric, magnetic, and electromagnetic fields, in the frequency range 0 Hz to 300 GHz. The exposure limits apply to persons permitted in restricted environments and to the general public in unrestricted environments. These limits are not intended to apply to the exposure of patients by or under the direction of physicians and care professionals, as well as to the exposure of informed volunteers in scientific research studies, or to the use of medical devices or implants. IEEE Std C95.1 TM

BioMedical Engineering OnLine, 2018

When radiofrequency (RF) currents flow through biological tissues, tissue heating can occur. Such... more When radiofrequency (RF) currents flow through biological tissues, tissue heating can occur. Such currents, as described in RF safety standards, are designated as "induced" currents or "contact" currents. Induced currents are those that are caused through the

Proceedings of the IEEE, 1980

measurements are conducted without regard to population distributions but rather from the viewpoi... more measurements are conducted without regard to population distributions but rather from the viewpoint of determining the maximum or highest intensities of exposure that are possible to be found in the environment. The principle purpose of this report is to provide the results of our efforts in the f i t instance. Previous discussions of USEPA activites in this area are available (Janes et al. [ 1 I ; Athey et al. [21; Tell and Mantiply [ 3 I). This report contains new and more extensive data and results for U.S. cities and uses an improved propagation modeling technique for generating estimates of population exposure. Additionally, a technique is discussed which provides insight to the consideration of the accuracy with which exposure estimates are obtained.

Radiation protection dosimetry, 2016

Measurements were conducted to investigate electric and magnetic fields (EMFs) from 120 Hz to 10 ... more Measurements were conducted to investigate electric and magnetic fields (EMFs) from 120 Hz to 10 kHz and 1.2 to 100 kHz in 9 electric or hybrid vehicles and 4 gasoline vehicles, all while being driven. The range of fields in the electric vehicles enclosed the range observed in the gasoline vehicles. Mean magnetic fields ranged from nominally 0.6 to 3.5 µT for electric/hybrids depending on the measurement band compared with nominally 0.4 to 0.6 µT for gasoline vehicles. Mean values of electric fields ranged from nominally 2 to 3 V m(-1) for electric/hybrid vehicles depending on the band, compared with 0.9 to 3 V m(-1) for gasoline vehicles. In all cases, the fields were well within published exposure limits for the general population. The measurements were performed with Narda model EHP-50C/EHP-50D EMF analysers that revealed the presence of spurious signals in the EHP-50C unit, which were resolved with the EHP-50D model.

1978 IEEE International Symposium on Electromagnetic Compatibility, 1978

Smart Grid Handbook, 2016

Nasa Sti Recon Technical Report N, May 1, 1974

The report describes an engineering analysis of the potential impact of proposed EPA Federal Radi... more The report describes an engineering analysis of the potential impact of proposed EPA Federal Radiation Protection guidance for radiofrequency radiation on the broadcast industry. The study was performed by developing computer models of the radiofrequency radiation on the ground near broadcast stations and applying the models to data bases of the stations. The models were developed using theoretical predictions, empirical data and an existing numerical electromagnetic code, and compared with field study data and other prediction techniques to determine their accuracy. Variations of the models incorporating possible mitigation strategies were applied in conjunction with the original models so that the number of effective fixes could also be studied. Descriptions of the models and the results of the study are presented.

Abstract : This report documents the purposes of discussion, observation, and characterization of... more Abstract : This report documents the purposes of discussion, observation, and characterization of experimental methodology used in research on the effects of pulsed magnetic fields on the chick embryo.

Workshop Held at Las Vegas Nev 3 5 Nov 1980, Jul 1, 1982

Nasa Sti Recon Technical Report N, Jun 1, 1978

Journal of Occupational and Environmental Hygiene, 2015

The southwest region of the United States is expected to experience an expansion of commercial so... more The southwest region of the United States is expected to experience an expansion of commercial solar photovoltaic generation facilities over the next 25 years. A solar facility converts direct current generated by the solar panels to three-phase 60-Hz power that is fed to the grid. This conversion involves sequential processing of the direct current through an inverter that produces low-voltage three-phase power, which is stepped up to distribution voltage (∼12 kV) through a transformer. This study characterized magnetic and electric fields between the frequencies of 0 Hz and 3 GHz at two facilities operated by the Southern California Edison Company in Porterville, CA and San Bernardino, CA. Static magnetic fields were very small compared to exposure limits established by IEEE and ICNIRP. The highest 60-Hz magnetic fields were measured adjacent to transformers and inverters, and radiofrequency fields from 5-100 kHz were associated with the inverters. The fields measured complied in every case with IEEE controlled and ICNIRP occupational exposure limits. In all cases, electric fields were negligible compared to IEEE and ICNIRP limits across the spectrum measured and when compared to the FCC limits (≥0.3 MHz).

Biological Effects and Dosimetry of Nonionizing Radiation, 1983

Determination of radiofrequency electromagnetic field expo-, sure is necessary in both biological... more Determination of radiofrequency electromagnetic field expo-, sure is necessary in both biological effects research work concerned with electromagnetic field effects and the assessment of possible hazards to exposed individuals. The situations include laboratory exposure of animals and human exposures in both the work place and non-occupational settings for determining compliance with applicable safety standards. Because of the common complications introduced by the environment such as multipath reflections and absorption caused by intervening attenuative media, resort is often made to a direct measurement of the ambient fields in lieu of the often impossible task of accurate mathematical computation.

Radiofrequency Radiation Standards, 1995

Despite the controversial nature of whether radiofrequency radiation (RFR) poses the potential fo... more Despite the controversial nature of whether radiofrequency radiation (RFR) poses the potential for adverse health effects in exposed individuals, there has been no lack of development of RFR exposure standards in recent years. During the last ten years, no less than an average of one new guideline or standard has been issued each year. Regulatory activities in the United States,1,2 Canada,3 the United Kingdom,4 Australia,5 Germany,6 China,7 and Czechoslovakia8 exemplify this prolific generation of new and, very commonly, more stringent and complex standards.

IEEE Transactions on Broadcast and Television Receivers, 1970

highly filtered, well regulated X-ray machine and its subsequent use to perform attenuation studi... more highly filtered, well regulated X-ray machine and its subsequent use to perform attenuation studies on picture tube glasses and bonding resins. The attenuation data were used to derive attenuation coefficients which are compared to those calculated from known chemical compositions at several photon energies. Measurements were made of the spectra from the picture tubes of two color television receivers. In one, the picture tube (GE 21 GFP22) was intact with its safety panel bonded to the face plate (see Fig. 1), while in Screen Shadow Mask Electron Guns Bonding Resin Safety Panel Fig. 1-Typical color television picture tube 82