Evaluation of HSP70 expression and DNA damage in cells of a human trophoblast cell line exposed to 1.8 GHz amplitude-modulated radiofrequency fields.
ABSTRACT The aim of this study was to determine whether high-frequency electromagnetic fields (EMFs) could induce cellular effects. The human trophoblast cell line HTR-8/SVneo was used as a model to evaluate the expression of proteins (HSP70 and HSC70) and genes (HSP70A, B, C and HSC70) of the HSP70 family and the primary DNA damage response after nonthermal exposure to pulse-modulated 1817 MHz sinusoidal waves (GSM-217 Hz; 1 h; SAR of 2 W/kg). HSP70 expression was significantly enhanced by heat, which was applied as the prototypical stimulus. The HSP70A, B and C transcripts were differentially expressed under basal conditions, and they were all significantly induced above basal levels by thermal stress. Conversely, HSC70 protein and gene expression was not influenced by heat. Exposing HTR-8/SVneo cells to high-frequency EMFs did not change either HSP70 or HSC70 protein or gene expression. A significant increase in DNA strand breaks was caused by exposure to H(2)O(2), which was used as a positive stimulus; however, no effect was observed after exposure of cells to high-frequency EMFs. Overall, no evidence was found that a 1-h exposure to GSM-217 Hz induced a HSP70-mediated stress response or primary DNA damage in HTR-8/SVneo cells. Nevertheless, further investigations on trophoblast cell responses after exposure to GSM signals of different types and durations are needed.
SourceAvailable from: Michele Wiens
Technical Report: Radiofrequency toolkit[Show abstract] [Hide abstract]
ABSTRACT: The Radiofrequency Toolkit was developed in response to requests from BC’s medical and environmental health officers to the BCCDC for assistance in assessing and communicating the risk to health from exposure to the many devices which emit radiofrequency waves. Students, public health residents, and specialists in epidemiology from outside BCCDC collaborated with staff from BCCDC and the National Collaborating Center for Environmental Health (NCCEH) on this project. The toolkit provides background on the physics of RF, its sources, measurement and exposure characteristics as well as an evaluation of the current scientific literature on potential biological and health effects associated with exposure to RF.
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ABSTRACT: The aim of this study isto examine whether radiofrequency (RF) used in cellular phone communications at a specific absorption rate (SAR) less than 1.2 w/kg could increase the spontaneous rate of sister chromatid exchanges (SCE) or elicit alterations both in the cell replication index (CRI) and mitotic index (MI) in human peripheral blood lymphocytes. Whole blood samples were obtained from twenty six healthy donors (male nonsmokers). Cultures were placed in sterile T-25 tissue flasks and sham-exposed or RF-exposed to 900 MHz or 1800 MHz radiation for 1 h, then incubated for 72 h at 37 °C. The mean SCE values of both RF exposure groups slightly increased, as compared with the sham-exposure group. However, there was no significant difference between the RF exposure groups and sham-RF exposure group. Compared with the negative control, both CRI and MI were non-significantly elevated after exposure to both frequencies, but to a lesser extent in case of 1800 MHz exposure. In view of the present guidelines of mutagenicity, which necessitates at least two-fold increase in SCE rate, RF is not considered as mutagenic.
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ABSTRACT: The objective of this paper is to compare realistic maximum electromagnetic exposure of human tissues generated by mobile phones with electromagnetic exposures applied during in vitro experiments to assess potentially adverse effects of electromagnetic exposure in the radiofrequency range. We reviewed 80 in vitro studies published between 2002 and present that concern possible adverse effects of exposure to mobile phones operating in the 900 and 1800 MHz bands. We found that the highest exposure level averaged over the cell medium that includes evaluated cells (monolayer or suspension) used in 51 of the 80 studies corresponds to 2 W/kg or less, a level below the limit defined for the general public. That does not take into account any exposure non-uniformity. For comparison, we estimated, by numerical means using dipoles and a commercial mobile phone model, the maximum conservative exposure of superficial tissues from sources operated in the 900 and 1800 MHz bands. The analysis demonstrated that exposure of skin, blood, and muscle tissues may well exceed 40 W/kg at the cell level. Consequently, in vitro studies reporting minimal or no effects in response to maximum exposure of 2 W/kg or less averaged over the cell media, which includes the cells, may be of only limited value for analyzing risk from realistic mobile phone exposure. We, therefore, recommend future in vitro experiments use specific absorption rate levels that reflect maximum exposures and that additional temperature control groups be included to account for sample heating. Bioelectromagnetics © 2015 Wiley Periodicals, Inc.Bioelectromagnetics 01/2015; DOI:10.1002/bem.21895 · 1.86 Impact Factor