Unknown authors · 1999
Researchers conducted a case-control study of 399 children with leukemia and 399 controls across five Canadian provinces from 1990 to 1994. Exposure assessment included 48-hour personal EMF measurement, wire coding, residential magnetic field measurements from conception to diagnosis, and 24-hour bedroom magnetic field measurement. Personal magnetic fields were not related to risk of leukemia (adjusted OR = 0.95, p for trend = 0.73) or acute lymphatic leukemia (OR = 0.93, p for trend = 0.64). No clear associations were found with predicted magnetic field exposure two years before diagnosis, over the lifetime, or with personal electric field exposure.
Unknown authors · 1999
Groups of 100 female Sprague–Dawley rats were initiated with a single 10 mg gavage dose of DMBA at 50 days of age and then exposed to ambient fields, 50 Hz magnetic fields at 1 or 5 Gauss, or 60 Hz fields at 1 Gauss for 18.5 hours per day, 7 days per week for 26 weeks. There was no effect of magnetic field exposure on body weight gains or the time of appearance of mammary tumors. Carcinoma incidence was 96%, 90%, 95%, and 85% for the DMBA controls, 1 G 50 Hz, 5 G 50 Hz, and 1 G 60 Hz groups respectively, total carcinoma numbers were 649, 494, 547, and 433 with significant decreases in the 1 G 50 Hz and 1 G 60 Hz groups, and the authors concluded there was no evidence that 50 or 60 Hz magnetic fields promoted breast cancer under the conditions of this assay.
Unknown authors · 1999
Unknown authors · 1999
Unknown authors · 1999
Researchers exposed HBL-100 cells and normal human mammary epithelial cells to 60 Hz EMF at flux densities of 0.1, 1.0, and 10.0 Gauss for periods ranging from 20 min to 24 h. Gene expression was quantitated using ribonuclease protection assays. EMF exposure had no statistically significant effect on basal levels of c-myc transcripts in either human breast cell model, and had no effect on alterations in c-myc expression induced by 12-O-tetradecanoylphorbol-13-acetate. Transcript levels of c-erbB-2, p53, p21, GADD45, bax, bcl-x, mcl-1, and c-fos were also unaffected by EMF exposure.
Unknown authors · 1999
Researchers exposed groups of 100 female Sprague-Dawley rats to 50 Hz magnetic fields at 1 or 5 G, or 60 Hz at 1 G, for 18.5 hours a day, 7 days a week, for 13 weeks after initiating mammary tumors with DMBA. A second study used a lower DMBA dose of 2 mg and exposed rats to 50 Hz fields at 1 or 5 G for the same duration. Magnetic field exposure did not affect body weight, tumor latency, or tumor size in either study, and the authors concluded there was no evidence that 50 or 60 Hz fields promoted breast cancer.
Unknown authors · 1999
Researchers conducted a population-based case-control study across England, Wales, and Scotland. They measured household and school magnetic fields for 2226 matched case-control pairs and estimated average exposure in the year before diagnosis. For children with mean exposures above 0.2 microT compared to below 0-1 microT, the adjusted odds ratio for all malignant disease combined was 0.87 (95% CI 0.56-1.35).
Li et al. · 1999
Researchers exposed human fibroblast cells to 837 MHz continuous microwaves for 2 hours at SAR levels of 0.9 or 9.0 W/kg. TP53 protein levels were measured by Western blot at 2, 8, 24, and 48 hours after exposure. No significant changes in TP53 protein expression were found in exposed cells compared to sham or untreated cells at any time point. No morphological alterations were observed in microwave-treated cells compared to sham-treated cells.
Higashikubo R et al. · 1999
Researchers exposed Fischer 344 rats implanted with 9L gliosarcoma cells to 835.62 MHz FMCW or 847.74 MHz CDMA fields with a nominal brain specific absorption rate of 0.75 +/- 0.25 W/kg. The animals were exposed for 4 hours a day, 5 days a week, starting 4 weeks before tumor implantation and continuing up to 150 days after. Sham-exposed rats injected with 2 to 10 cells had a median survival of 70 days with 27% surviving to 150 days; those with 11 to 36 cells had a median survival of 52 days and 14% final survival; those with 37 to 100 cells had a median survival of 45 days and 0% survival. Statistical comparison showed no significant differences in survival curves between RF-exposed and sham-exposed animals in any of the three cell-dose groups.
Chagnaud, JL, Moreau, JM, Veyret, B · 1999
Two-month-old female Sprague-Dawley rats were treated by injection of benzo(a)pyrene and irradiated with GSM (Global System for Mobile)-modulated 900-MHz microwaves in an anechoic chamber at 55 or 200 mu W cm-2 (75 and 270mWkg-1 average whole-body SAR, 2h daily for 2 weeks). Microwave exposure had no effect on tumour development, no acceleration or delays in tumour onset were observed, and animal survival was not modified while serum auto-antibody levels were similar in exposed and sham-exposed groups.
Johnson EH, Chima SC, Muirhead DE · 1999
Researchers examined an adult squirrel monkey with a history of long-term exposure to microwave radiation that had a malignant tumor in the right cerebral cortex. Microscopy showed sheets of moderate-sized cells with clear cytoplasm and central nuclei, resembling an oligodendroglioma, with malignant features including nuclear pleomorphism, mitotic figures, and necrosis. Immunohistochemical analysis supported a neuronal origin with positivity for neurofilament proteins and neuron-specific enolase, while vimentin and glial fibrillary acidic protein were negative except in reactive astrocytes. The tumor showed strong positivity for Ki-67 antigen and p53 oncoprotein, indicating aggressive malignant nature, and was diagnosed as a cerebral primitive neuroectodermal tumor.
Hardell et al. · 1999
Researchers conducted a case-control study with 209 brain tumour cases and 425 controls in Sweden. Overall cellular telephone use yielded an odds ratio of 0.98 with a 95% confidence interval. Separate analyses for the digital GSM system and the analogue NMT system gave odds ratios of 0.97 and 0.94 respectively. A non-significantly increased risk was found for tumours in the temporal or occipital lobe on the same side as phone use. The increased risk was only seen for use of the NMT system.
Dreyer NA, Loughlin JE, Rothman KJ · 1999
The initial protocol called for continuing surveillance for mortality. Access to data beyond 1 year was blocked by a class-action lawsuit challenging the legality of monitoring product safety through record linkage.
Adey WR et al. · 1999
Researchers tested an 836.55 MHz NADC-modulated field in a 2-year bioassay with fetal exposure in Fischer 344 rats. Of 236 original rats, 182 (77%) survived to termination at age 709-712 days. There was no evidence of tumorigenic effects in the CNS from TDMA field exposure. Exposed animals showed trends toward reduced incidence of spontaneous CNS tumors (P < 0.16) and ENU-induced CNS tumors (P < 0.16). In preterm rats where neural tumors caused death, fields decreased ENU-induced tumor incidence (P < 0.03).
Unknown authors · 1998
Unknown authors · 1998
Researchers conducted two population-based case-control studies on childhood leukemia in northwestern Germany and Berlin from 1992 to 1996. They obtained 24-hour measurements for 176 cases and 414 controls. Multivariate regression analysis comparing exposures of 0.2 microT or more to lower exposures yielded an odds ratio of 2.3 with a 95% confidence interval of 0.8 to 6.7.
Unknown authors · 1998
Public concern about EMF and cancer stems from epidemiological studies that appear to show an association between cancer and residence near power lines. The epidemiological evidence falls far short of establishing a causal relationship, and biophysics suggests biological effects are implausible at environmental field strengths. Approximately 100 published reports looked for evidence that power-frequency fields have genotoxic or epigenetic activity. These studies found no replicated evidence that power-frequency fields have the potential to cause or contribute to cancer.
Unknown authors · 1998
They identified 699 female breast cancer cases and 9 male cases, with one matched control per female case and eight per male case. In women younger than 50 at diagnosis, the relative risk was 1.8 (95% CI 0.7-4.3). Among estrogen receptor-positive women younger than 50, the relative risk increased to 7.4 (95% CI 1.0-178.1).
Unknown authors · 1998
Researchers assessed whether a 60-Hz magnetic field at 0.1 mT could reproduce earlier reported transcription changes in c-fos, c-jun, and c-myc oncogenes in CEM-CM3 cells. Cells were exposed for 15, 30, 60, or 120 minutes to the field or to a sham condition with coils in bucking mode. Transcription rates measured by nuclear run-on assay and transcript levels measured by Northern analysis showed no significant difference between exposed and sham or control cells at any time point.
Imaida K et al. · 1998
Researchers exposed male F344 rats to a 929.2 MHz electromagnetic near-field for 90 minutes a day, five days a week, over six weeks. The exposed rats showed no significant difference in GST-P positive foci numbers or areas compared to sham-exposed rats. Maximum local specific absorption rates were 7.2 to 6.6 W/kg in the whole body and 2.0 to 1.7 W/kg in the liver.
Imaida et al. · 1998
Researchers exposed male F344 rats to a 1.439 GHz TDMA electromagnetic near-field for 90 minutes a day, 5 days a week, over 6 weeks. The rats were initiated with diethylnitrosamine and underwent partial hepatectomy at week 3. Peak liver SARs ranged from 1.91 to 0.937 W/kg and whole-body average SARs from 0.680 to 0.453 W/kg at 0.33 W antenna power. Exposure did not significantly alter the numbers or areas of GST-P-positive foci in the liver compared to sham-exposed rats. Serum levels of corticosterone, ACTH, and melatonin were increased in exposed rats.
Frei et al. · 1998
Researchers exposed 100 C3H/HeJ mice to continuous-wave 2450 MHz RF radiation at 1.0 W/kg for 78 weeks, 20 hours per day, 7 days per week, while 100 mice were sham-exposed. There was no significant difference in mammary tumor incidence between exposed mice (38%) and sham-exposed mice (30%). Latency to tumor onset was similar: 62.5 weeks for exposed mice and 62.0 weeks for sham-exposed mice. Histopathological evaluation found no significant difference in malignant, metastatic, or benign neoplasms between groups.
Michelozzi P, Ancona C, Fusco D, Forastiere F, Perucci CA · 1998
Researchers conducted a small area study to investigate a leukemia cluster near a high-power radio transmitter in a peripheral area of Rome. Leukemia mortality within 3.5 km (5,863 inhabitants) was higher than expected (SMR=2.5, 95% confident interval 1.07-4.83). The excess was due to a significant higher mortality among men (7 cases observed, SMR=3.5). Stone's test adjusted for socio-economic confounding showed a significant decline in risk with distance from the transmitter only among men (p=0.005), while the p-value for both sexes was 0.07.
Hardell L, Nasman A, Ohlson CG, Fredrikson M. · 1998
The case-control study enrolled 148 cases (91% response) and 314 controls (87% response), including 101 seminoma and 47 embryonal testicular cancer cases. Occupational plastics work yielded an odds ratio of 2.9 with a 95% confidence interval of 1.3-6.5. Farming (OR 3.1, CI 1.03-9.1) and contact with farm animals (OR 3.3, CI 1.00-10.9) increased risk for embryonal cancer but not for seminoma. Exposure to insect repellents, mostly containing DEET, gave an odds ratio of 1.7 (CI 1.03-2.8) for all testicular cancer with a dose-response effect. Video display unit work gave an odds ratio of 1.5 (CI 0.98-2.3), and for 480 working days (median) the odds ratio increased to 1.8 (CI 1.1-3.2).
Unknown authors · 1997
