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PubMed2006

The number of genes changing expression after chronic exposure to code division multiple access or frequency DMA radiofrequency radiation does not exceed the false-positive rate.

Experiments with cultured C3H 10T 1/2 cells were performed to determine if exposure to cell phone radiofrequency (RF) radiations induce changes in gene expression. Following a 24 h exposure of 5 W/kg specific adsorption rate, RNA was extracted from the exposed and sham control cells for microarray analysis on Affymetrix U74Av2 Genechips. Cells exposed to 0.68 Gy of X-rays with a 4-h recovery were used as positive controls. The number of gene expression changes induced by RF radiation was not greater than the number of false positives expected based on a sham versus sham comparison. In contrast, the X-irradiated samples showed higher numbers of probe sets changing expression level than in the sham versus sham comparison.

Animals↗
PubMed2001

Driven to distraction: dual-Task studies of simulated driving and conversing on a cellular telephone.

Dual-task studies assessed the effects of cellular-phone conversations on performance of a simulated driving task. Performance was not disrupted by listening to radio broadcasts or listening to a book on tape. Nor was it disrupted by a continuous shadowing task using a handheld phone, ruling out, in this case, dual-task interpretations associated with holding the phone, listening, or speaking, However significant interference was observed in a word-generation variant of the shadowing task, and this deficit increased with the difficulty of driving. Moreover unconstrained conversations using either a handheld or a hands-free cell phone resulted in a twofold increase in the failure to detect simulated traffic signals and slower reactions to those signals that were detected. We suggest that cellular-phone use disrupts performance by diverting attention to an engaging cognitive context other than the one immediately associated with driving.

Adolescent↗
PubMed1999

Spontaneous and nitrosourea-induced primary tumors of the central nervous system in Fischer 344 rats chronically exposed to 836 MHz modulated microwaves.

We have tested an 836.55 MHz field with North American Digital Cellular (NADC) modulation in a 2-year animal bioassay that included fetal exposure. In offspring of pregnant Fischer 344 rats, we tested both spontaneous tumorigenicity and the incidence of induced central nervous system (CNS) tumors after a single dose of the carcinogen ethylnitrosourea (ENU) in utero, followed by intermittent digital-phone field exposure for 24 months. Far-field exposures began on gestational day 19 and continued until weaning at age 21 days. Near-field exposures began at 35 days and continued for the next 22 months, 4 consecutive days weekly, 2 h/day. SAR levels simulated localized peak brain exposures of a cell phone user. Of the 236 original rats, 182 (77%) survived to the termination of the whole experiment and were sacrificed at age 709-712 days. The 54 rats (23%) that died during the study ("preterm rats") formed a separate group for some statistical analyses. There was no evidence of tumorigenic effects in the CNS from exposure to the TDMA field. However, some evidence of tumor-inhibiting effects of TDMA exposure was apparent. Overall, the TDMA field-exposed animals exhibited trends toward a reduced incidence of spontaneous CNS tumors (P < 0. 16, two-tailed) and ENU-induced CNS tumors (P < 0.16, two-tailed). In preterm rats, where primary neural tumors were determined to be the cause of death, fields decreased the incidence of ENU-induced tumors (P < 0.03, two-tailed). We discuss a possible approach to evaluating with greater certainty the possible inhibitory effects of TDMA-field exposure on tumorigenesis in the CNS.

Animals↗
PubMed2006

Implicit attitudes toward nuclear power and mobile phone base stations: support for the affect heuristic.

The implicit association test (IAT) measures automatic associations. In the present research, the IAT was adapted to measure implicit attitudes toward technological hazards. In Study 1, implicit and explicit attitudes toward nuclear power were examined. Implicit measures (i.e., the IAT) revealed negative attitudes toward nuclear power that were not detected by explicit measures (i.e., a questionnaire). In Study 2, implicit attitudes toward EMF (electro-magnetic field) hazards were examined. Results showed that cell phone base stations and power lines are judged to be similarly risky and, further, that base stations are more closely related to risk concepts than home appliances are. No differences between experts and lay people were observed. Results of the present studies are in line with the affect heuristic proposed by Slovic and colleagues. Affect seems to be an important factor in risk perception.

Journal Article↗
PubMedDate not supplied

Physician-investigator phone elicitation of consent in the field: a novel method to obtain explicit informed consent for prehospital clinical research.

OBJECTIVE: To describe and report the feasibility of a novel field telephonic strategy to elicit explicit informed consent in prehospital trials for conditions in which patients retain decision-making capacity. METHODS: In a pilot prehospital neuroprotective stroke therapy trial, ambulances carried written informed consent forms and dedicated trial cellular phones permitting rapid connection to on call physician-investigators. The physician-investigator discussed the trial with the consent provider [patient if competent, on scene legally authorized representative (LAR) if patient not competent] by phone, while paramedics carried out prehospital care duties unimpeded. RESULTS: 32 patients met consent elicitation criteria. 20 (63%) were enrolled. The most frequent reasons for non-enrollment were: patient not competent and no available on-scene LAR-5; patient/LAR declined participation-4. Among enrollees, 15 (75%) were competent and self-enrolled; 5 (25%) were not competent and were enrolled by LAR family members. Site of consent initiation was: patient home-15 (74 = 5%), work-2(10)%, other-3(15)%. Consent was elicited via cell phone in 11 (55%) and site landline in 9 (45%). Compared with patients enrolled in prior studies employing standard in-hospital consent, prehospital consent procedures reduced time from paramedic arrival on-scene to start of study agent (26 vs 139 mins, p < 0.0001), and did not prolong the on-scene to ED arrival time (37 vs 34 min, p = 0.50). No patient/family withdrew consent during the 3-month follow-up period. CONCLUSION: Physician phone elicitation of prehospital research consent from individuals with retained competency or on-scene legally authorized representatives is feasible, permits rapid patient study entry, and does not delay field transport times.

Biomedical Research↗
PubMedDate not supplied

Carcinogenic effects of hyperthermia.

The purpose of this paper is to assess the evidence for and against the premise that hyperthermia is carcinogenic. The paper is one of several published in this issue of the International Journal of Hyperthermia on the subject of the health risks of hyperthermia. The motivation for this issue of the journal was the result of a World Health Organization workshop that dealt with this issue, as it relates to exposure of the population to RF fields. Since hyperthermia can be a natural consequence of such exposures, the health risks of hyperthermia are relevant in this context. Particularly in the case of carcinogenesis, it is necessary to provide a brief overview of the data that have been generated to examine the carcinogenic risks of RF exposure, so that these results can be compared with studies that have examined the carcinogenic risks of hyperthermia. For this reason, the paper is organized into three sections dealing with: (1) effects of heat on DNA damage/repair and mutations, (2) in vivo studies evaluating the carcinogenic potential of heat alone and combined with other carcinogens, and (3) in vivo studies involving RF exposures. The bulk of the data presented indicate that hyperthermia alone is not carcinogenic. If hyperthermia occurs in the presence of exposure to known carcinogens, such as radiation or chemical carcinogens there is the potential for modulation of carcinogenic effects of those agents. In some circumstances, hyperthermia can actually protect against tumour formation. In other instances, hyperthermia clearly increases incidence of tumour formation, but this occurs following thermal exposures (several degrees C temperature rise for up to 1 h or more) and radiation (therapeutic levels as for treatment of cancer) or chemical carcinogen doses higher than would be encountered by the general population. The extrapolation of these results to the general population, where radiation exposure levels would be at background and temperature rise from incidental RF exposure, such as cell phones (which are estimated to cause no more than 0.1 degrees C temperature rise) is not recommended. Current evidence indicates that the temperature elevations resulting from RF exposure are not carcinogenic. Caution should be used in situations where exposure to known carcinogens is combined with thermal exposures high enough to cause tissue damage. A summary of thermal thresholds for tissue damage from hyperthermia is presented in another paper in this special issue (Dewhirst et al.). No data exist that examine the carcinogenic risks of chronic thermal exposures below the threshold for detectable tissue damage, either alone or in combination with known carcinogens. This is an important goal for future research.

Animals↗
PubMed2004

Generic UMTS test signal for RF bioelectromagnetic studies.

This report outlines the characteristics of universal mobile telecommunications system (UMTS) signals and discusses the signal parameters with respect to their possible biological relevance in order to define a generic UMTS test signal (GUS) for experiments aiming at the investigation of biological effects of weak electromagnetic fields. The GUS includes features of a real UMTS signal and especially the characteristics of UMTS, which differ from those of already applied second generation mobile communication systems (GSM 900, DCS1800, PCS1900, IS-95). It has been specified on the basis of the recommendations of a working group of the German Forschungsgemeinschaft Funk (FGF) with a focus on the mechanisms of UMTS which are responsible for slow term signal contributions, i.e., low frequency variations of the radio frequency (RF) envelope, since the hypothetical possibility of biological relevance of weak electromagnetic fields is often attributed to time variations of the RF envelope with frequencies close to those of natural processes. In this respect, it is also shown that the mandatory power control loop in UMTS gives rise to very strong 1.5 kHz variations on the air interface. Based upon the concept of the GUS, a UMTS test signal generator (GUS6960S) is described.

Cell Phone↗
PubMed2005

Evaluation of genotoxic effects in human peripheral blood leukocytes following an acute in vitro exposure to 900 MHz radiofrequency fields.

Human peripheral blood leukocytes from healthy volunteers have been employed to investigate the induction of genotoxic effects following 2 h exposure to 900 MHz radiofrequency radiation. The GSM signal has been studied at specific absorption rates (SAR) of 0.3 and 1 W/kg. The exposures were carried out in a waveguide system under strictly controlled conditions of both dosimetry and temperature. The same temperature conditions (37.0 +/- 0.1 degrees C) were realized in a second waveguide, employed to perform sham exposures. The induction of DNA damage was evaluated in leukocytes by applying the alkaline single cell gel electrophoresis (SCGE)/comet assay, while structural chromosome aberrations and sister chromatid exchanges were evaluated in lymphocytes stimulated with phytohemagglutinin. Alterations in kinetics of cell proliferation were determined by calculating the mitotic index. Positive controls were also provided by using methyl methanesulfonate (MMS) for comet assay and mitomycin-C (MMC), for chromosome aberration, or sister chromatid exchange tests. No statistically significant differences were detected in exposed samples in comparison with sham exposed ones for all the parameters investigated. On the contrary, the positive controls gave a statistically significant increase in DNA damage in all cases, as expected. Thus the results obtained in our experimental conditions do not support the hypothesis that 900 MHz radiofrequency field exposure induces DNA damage in human peripheral blood leukocytes in this range of SAR.

Cell Phone↗
PubMed2005

Electromagnetic fields (GSM 1800) do not alter blood-brain barrier permeability to sucrose in models in vitro with high barrier tightness.

We previously reported that electromagnetic fields (EMFs) [GSM 1800 standard (Global System for Mobile Communications, 1800 MHz)] increased sucrose permeation across the blood-brain barrier (BBB) in vitro. The cell culture model used in our previous study was comprised of rat astrocytes in coculture with porcine brain microvascular endothelial cells (PBECs). In this study, after optimization of cell culture conditions, distinctly improved barrier tightness was observed, accompanied by a loss of susceptibility to EMF-related effects on BBB permeability. Cell cultures were exposed for 1-5 days at an average specific absorption rate (SAR) of 0.3 W/kg in the identical exposure system as described before. To quantify barrier tightness, sucrose permeation across exposed PBEC was measured and compared to values of sham exposed cells and to a control group. Additionally, observations in the BBB coculture system were complemented by similar experiments using two other in vitro models, composed of PBEC monocultures with or without serum. These three models display distinctly higher barrier tightness than the previously used system. In all three BBB models, sucrose permeation across the cell layers remained unaffected by exposure to a GSM 1800 field for up to 5 days. We thus could not confirm enhanced permeability of the BBB in vitro after EMF exposure as reported before since the in vitro barrier tightness in these experiments is now more like that of the in vivo situation.

Animals↗
PubMed2005

Differences in RF energy absorption in the heads of adults and children.

There has been a long and controversial debate on possible differences in electromagnetic (EM) energy absorption between adults and children during cell phone usage. Some published studies report higher specific absorption rate (SAR) in children and explain this based on smaller head size. More recently, age dependent changes of the dielectric tissue parameters have again ignited the discussion. This study intends to give a comprehensive review of the current state of knowledge about the parameters and mechanisms affecting the exposure of the mobile phone user with special focus on the exposure of children. Discussed are the absorption mechanism, tissue parameters, the effect of the pinna, and the uncertainties associated with head models based on spheroids, scaled adult heads, and magnetic resonance imaging (MRI) data of children. The conclusions of the review do not support the assumption that the energy exposure increases due to smaller heads, but identifies open issues regarding the dielectric tissue parameters and the thickness of the pinna.

Adult↗
PubMed2005

Lack of effects of 1439 MHz electromagnetic near field exposure on the blood-brain barrier in immature and young rats.

Possible effects of 1439 MHz electromagnetic near field (EMF) exposure on the blood-brain barrier (BBB) were investigated using immature (4 weeks old) and young (10 weeks old) rats, equivalent in age to the time when the BBB development is completed and the young adult, respectively. Alteration of BBB related genes, such as those encoding p-glycoprotein, aquaporin-4, and claudin-5, was assessed at the protein and mRNA levels in the brain after local exposure of the head to EMF at 0, 2, and 6 W/kg specific energy absorption rates (SARs) for 90 min/day for 1 or 2 weeks. Although expression of the 3 genes was clearly decreased after administration of 1,3-dinitrobenzene (DNB) as a positive control, when compared with the control values, there were no pathologically relevant differences with the EMF at any exposure levels at either age. Vascular permeability, monitored with reference to transfer of FITC-dextran, FD20, was not affected by EMF exposure. Thus, these findings suggest that local exposure of the head to 1439 MHz EMF exerts no adverse effects on the BBB in immature and young rats.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2006

Radiofrequency radiation does not induce stress response in human T-lymphocytes and rat primary astrocytes.

Heat shock proteins (HSPs) are rapidly induced by a variety of stressors, including heat shock, ethanol, heavy metals, UV, and gamma-radiation. Mitogen-activated protein kinases (MAPKs) are also involved in the stress transduction pathways in all eukaryotes. In this study, we attempted to determine whether radiofrequency (RF) radiation is able to induce a non-thermal stress response. Human T-lymphocyte Jurkat cells and rat primary astrocytes were exposed to 1763 MHz of RF radiation at an average specific absorption rate (SAR) of either 2 W/kg or 20 W/kg, for 30 min or 1 h. Temperature was completely controlled at 37 +/- 0.2 degrees C throughout the exposure period. The sham exposures were performed under exactly identical experimental conditions without exposure to RF radiation. We assessed alterations in the expression of HSPs and the activation of MAPKs in the RF-exposed cells. No detectable difference was observed in the expression levels of HSP90, HSP70, and HSP27. The phosphorylation status of MAPKs, extracellular signal-regulated kinases (ERK1/2), c-Jun N-terminal protein kinases (JNK1/2), or p38, did not change significantly. In order to determine whether RF radiation can promote the effects of 12-O-tetradecanoylphorbol 13-acetate (TPA) on stress response, cells were exposed to RF radiation coupled with TPA treatment. When TPA alone was applied, the MAPKs were found to be phosphorylated in a dose-dependent manner. However, RF radiation did not result in any enhancement of TPA-induced MAPK phosphorylation. Neither TPA nor RF radiation exerted any detectable effect on the induction of HSPs. These results indicate that 1763 MHz RF radiation alone did not elicit any stress response, nor did it have any effect on TPA-induced MAPK phosphorylation, under our experimental conditions.

Animals↗
PubMed2002

Microwave exposure induces Hsp70 and confers protection against hypoxia in chick embryos.

To determine if microwave exposure could elicit a biological effect in the absence of thermal stress, studies were designed in which chick embryos were exposed to athermal microwave radiation (915 MHz) to look for induction of Hsp70, a protein produced during times of cellular stress that aids in the protection of cellular components. Levels of Hsp70 were found to increase within 2 h, with maximum expression ( approximately 30% higher than controls) typically occurring by 3 h from the start of exposure. Other embryos were exposed to microwave radiation prior to being subjected to hypoxic stress, and were found to have significantly higher survival (P < 0.05) following re-oxygenation than non-exposed controls. The results of these studies indicate that not only can athermal microwave exposures activate the stress protein response pathway; they can also enhance survivability following exposure to a subsequent, potentially lethal stress. From a public health standpoint, it is important that more studies be performed to determine if repeated exposures, a condition likely to be found in cell phone use, are still beneficial.

Adaptation, Physiological↗
PubMed2005

The association of distraction and caution displayed by pedestrians at a lighted crosswalk.

The rates of deaths and injuries among pedestrians have fallen in recent years, but still remain public health problems as about 5000 pedestrians die each year. Because pedestrians have been shown to be responsible or partially responsible for many of the crashes in which they are involved, we sought to assess the relationship of distracted walking and performing routine cautionary behaviors of pedestrians crossing a busy street in a southwestern city at an intersection, adjacent a university. The behavior of 866 individuals was recorded by trained observers as pedestrians walked across a 105-foot wide street served by a stop light and zebra painted crosswalk. We defined distracted pedestrians as those wearing headphones, talking on a cell phone, eating, drinking, smoking or talking as they crossed the street. Caution was measured by looking left and right, and entering the crosswalk only when the white proceed light was illuminated. We found that only 13.5% of walkers looked left and right and entered the crosswalk while the white light was flashing. Approximately 20% of walkers were distracted as they crossed the street. Regression analysis indicated that distraction was negatively, but weakly associated with displaying cautious pedestrian behaviors. Because traffic lights were routinely ignored and lack of caution was predicted by distraction, we suggest that inexpensive education efforts target pedestrians near college campuses.

Accidents, Traffic↗
PubMed2025

Men's Knowledge, Attitudes, Practices, Cultural Beliefs, and Perceived Risk and Susceptibility Regarding Prostate Cancer in the Vhembe District, Limpopo Province, South Africa.

BACKGROUND: Prostate cancer (PCa) awareness and knowledge among men in Vhembe District, Limpopo Province, South Africa, remain inadequately studied despite the high local burden of the disease. This study investigates the knowledge, attitudes, practices, cultural beliefs, and perceived risk of PCa among men aged 40 and above in selected villages under the Mphaphuli and Niani tribal authorities. METHODS: A quantitative survey was conducted with 431 men, utilizing a questionnaire adapted from the African Women Awareness of Cancer (AWACAN) tool. The questionnaire, translated into Tshivenda, assessed socio-demographic data, awareness, knowledge of risk factors and symptoms, health-seeking behavior, and barriers to seeking medical help. RESULTS: The study revealed that 51.3% of participants had heard of PCa, while 48.7% had not. Awareness varied significantly with age, relationship status, education level, and language. Older men and those with higher education levels were more knowledgeable about PCa. Clinics, hospitals, and media were the primary sources of information. Misconceptions about risk factors were prevalent, with 24.0% of men indicating a preference for traditional healers for PCa symptoms. Barriers to medical help included fear of the disease, procedural fears, and cultural taboos. Multivariate analysis identified significant factors associated with PCa knowledge, including age, language, access to tap water, and cell phone ownership. CONCLUSION: These findings underscore the importance of targeted educational interventions considering sociodemographic and cultural contexts. Future public health initiatives should focus on bridging the gap between traditional and modern medical practices to enhance health outcomes in the Vhembe District and similar settings.

Humans↗
PubMed1992

Mammography knowledge and intentions among insured women.

UNLABELLED: METHOD. A survey was conducted among 1,113 randomly selected insured state university employees to evaluate knowledge of the American Cancer Society mammography guidelines, awareness of insurance coverage for screening mammograms, previous guideline adherence, and future mammography intentions. RESULTS: The survey, which included two mailings with follow-up phone cells of nonresponders, had a refusal rate of 6%. Respondents were relatively more likely to know the guideline for older age groups; 77% knew the guidelines for women 50+. Over one-third of the responders were not aware that their insurance policy covered screening mammograms. For women who had never had a mammogram, insurance knowledge was significantly related to intentions to have a mammogram in the future. Previous screening adherence, as well as future intentions, was positively related to the age of the respondent. The results are contrasted with those of previous studies, and the implications for the content of future breast cancer screening campaigns are discussed.

Adult↗
PubMed2005

Media literacy for clinicians and parents.

Families and children are in the midst of a media revolution. Television, Internet access, instant messaging, cell phones, and interactive video games are delivering more information for more hours than ever in history. Exposure is occurring at younger and younger ages, often without parental oversight or interpretation. The impact on children is just beginning to be studied. Does media exposure prepare children for the world in which they live or deprive them of critical developmental opportunities? Does the steady display of violence contribute to violent behavior? This article presents a developmental context, discusses the research conducted to date, reviews the recommendations of major organizations, and tries to take a balanced perspective in the midst of a rising tide of media, technology, commercialism, and controversy.

Adolescent↗
PubMedDate not supplied

Facing SARS: psychological impacts on SARS team nurses and psychiatric services in a Taiwan general hospital.

OBJECTIVE: The outbreak of severe acute respiratory syndrome (SARS) in 2003 resulted in 346 probable SARS cases and 37 deaths in Taiwan. This descriptive study, which was conducted from May to June 2003, intended to identify staff stress and coping strategies among a SARS team of nursing staff during the outbreak. METHOD: Twenty-six female nurses of the SARS team completed a questionnaire about their experiences serving in the SARS team. RESULTS: SARS had both positive and negative psychological impacts on the nurses. While worrying about infecting their families and colleagues, nurses were able to cope with the situation through various means. Additional findings include the need for more psychiatric staff to provide flexible and continuous service, the importance of meetings to improve teamwork and reduce conflict between doctors and nurses and the useful discovery that video cell phones provided needed reassurance from afar to the worried families of the nurses. CONCLUSION: This study reinforces the importance and benefits of psychiatric services for SARS team members in reducing their secondary traumatization. It is hoped that the results will enhance our knowledge on the needs of frontline health care workers and support the planning of better psychiatric services in future epidemics.

Adult↗