Unknown authors · 1997
Researchers conducted a case-control study in northern Taiwan matching on date of birth, sex, and date of diagnosis to evaluate risks of adult leukemia, brain tumors, and female breast cancers in relation to residential exposure to 60-Hertz magnetic fields. The analysis included 870 leukemia cases, 577 brain tumor cases, and 1,980 female breast cancer cases. For leukemia, exposure to magnetic fields above 0.2 microtesla versus below 0.1 microtesla yielded an odds ratio of 1.4 (95% CI = 1.0-1.9), and living within 50 meters versus 100 meters or more from transmission lines gave a relative risk of 2.0 (95% CI = 1.4-2.9).
Unknown authors · 1997
Researchers conducted a nested case-control study of children aged 0 to 14 years who lived in census wards crossed by high-voltage power lines during selected years from 1960 to 1989. Exposure to electric and magnetic fields was calculated using computer programs that accounted for power line characteristics and distance. No association was found between time-weighted average magnetic field exposure and cancer at all sites, brain tumors, lymphoma, or leukemia. Cancer at other sites showed elevated odds ratios in the two highest exposure categories for some exposure measures, but the researchers noted that no firm conclusions could be drawn due to small numbers.
Unknown authors · 1997
The population-based case-control study conducted in northwestern Germany between 1992 and 1995 included 129 children with leukemia and 328 controls. Exposure was assessed by 24-hour magnetic field measurements in the child's bedroom at the residence where the child had lived longest before diagnosis. For exposure above 0.2 microtesla the odds ratio was 3.2 with a 95 percent confidence interval of 0.7 to 14.9, based on four leukemia cases and three controls. Exploratory analyses found no statistically significant increases for other magnetic field characteristics at varying cut-points.
Unknown authors · 1997
Researchers examined mortality trends among a cohort of 40,335 electric utility workers with at least one year of experience from 1960 to 1991, observing 3,753 deaths. They used standardized mortality ratios and internal cohort analyses to compare mortality across occupational groups. Standardized mortality ratios were generally at or below 1.0, indicating lower overall mortality, cardiovascular disease, cancer, and nonintentional injury rates than the general population. Internal comparisons showed higher respiratory cancer mortality for field staff, linecrew, and power plant workers relative to office staff, and higher injury mortality for nonmanagement occupations.
Unknown authors · 1997
Many epidemiologic studies suggest a relationship between leukemia incidence and exposure to 50/60 Hz magnetic fields. Radiofrequency currents used for communications have been detected on high- and medium-voltage lines. The intensity of RF fields is low but induced currents in the human body increase with frequency, so the authors argue RF fields must be considered in epidemiologic studies.
Unknown authors · 1997
Researchers reviewed studies on leukaemia risk among people living near high voltage transmission lines of 49 kV and above. They calculated combined risks for distances of 50 meters and 25 meters and for magnetic field exposures at 2, 3, 4, and 10 milligauss. The combined analysis showed an odds ratio of 1.3 with a 95% confidence interval of 1.0 to 1.7 for exposures of 2 milligauss or higher. Odds ratios increased at higher exposures of 3, 4, and 10 milligauss, and risks were also elevated at distances of 50 and 25 meters from the lines.
Unknown authors · 1997
Researchers conducted a case-control study in Greece from 1993 to 1994 examining residential proximity to electrical power lines and childhood leukemia. The study included 117 incident cases of childhood leukemia and 202 matched controls. No statistically significant elevations of disease risk were found at higher exposure levels across four magnetic field exposure measures.
Vijayalaxmi et al. · 1997
C3H/HeJ mice prone to mammary tumors were exposed to 2450 MHz RF radiation at 1.0 W/kg for 20 hours per day, 7 days a week, over 18 months, with sham-exposed controls and positive controls treated with mitomycin C. The incidence of micronuclei in peripheral blood and bone marrow did not differ significantly between RF-exposed and sham-exposed groups. Positive controls treated with mitomycin C showed significantly elevated micronuclei frequencies. A separate analysis of mice that developed mammary tumors also found no significant differences in micronuclei frequency between exposure groups.
Stagg RB, Thomas WJ, Jones RA, Adey WR · 1997
Researchers exposed transformed and normal rat glial cells to an 836.55 MHz packet-modulated RF field at power densities of 0.09, 0.9, and 9 mW/cm2, with SARs from 0.15 to 59 muW/g. Primary rat glial cells showed no significant differences in DNA synthesis between sham and RF-exposed conditions for either log-phase or serum-starved cultures. C6 glioma cells exposed at 5.9 muW/g SAR showed small but significant increases in thymidine incorporation in 38% of experiments. Growth curves showed no differences between sham and RF-exposed cultures for either cell type, and doubling times of C6 glioma cells did not differ significantly.
Salford LG, Brun A, Persson BRR · 1997
Researchers used Fischer 344 rats of both sexes with implanted glioma cells (RG2 and N32) in a matched-pair design. Starting on day 5 after inoculation, rats were exposed for 7 hours a day, 5 days a week for 2–3 weeks to 915 MHz continuous or pulse-modulated microwaves. The study found no significant difference in tumour size between exposed and control animals. Tumour size was estimated as the volume of an ellipsoid after histopathological examination of all brains.
Cain CD, Thomas DL, Adey WR · 1997
The study tested whether a TDMA-modulated RF field and the tumor promoter TPA together increase focus formation of transformed cells cocultured with parental C3H/10T1/2 murine fibroblasts. Cell cultures were exposed to an 836.55 MHz TDMA-modulated field at specific absorption rates of 0.15, 1.5, and 15 μW/g in a repeating cycle of 20 minutes on and 20 minutes off continuously for 28 days. RF exposure did not significantly alter TPA-induced focus formation at any of the tested exposure levels across multiple independent experiments.
Lagorio S et al. · 1997
Researchers investigated the mortality of Italian plastic-ware workers exposed to radiofrequency fields from dielectric heat sealers. Follow-up ran from 1962 to 1992 and the analysis included 481 women workers representing 78% of person-years. Mortality from malignant neoplasms was slightly elevated and increased risks of leukemia and accidents were detected. The all-cancer standardised mortality ratio was higher among women in the sealing department than in the whole cohort.
Dolk H, Elliott P, Shaddick G, Walls P, Thakrar B · 1997
Researchers conducted a small-area study of cancer incidence from 1974 to 1986 near 20 high-power TV and FM radio transmitters in Great Britain using the national database of postcoded cancer registrations with population and socioeconomic data from the 1981 census. The study examined adult leukemias, skin melanoma, bladder cancer, childhood leukemia, and brain cancer. A decline in risk of adult leukemia was found for all transmitters combined (p=0.05), but excess risk was no more than 15% at any distance up to 10 km and there was no excess within 2 km (O/E ratio 0.97, 95% CI 0.78-1.21). For childhood leukemia, brain cancer, adult skin melanoma, and bladder cancer, results did not indicate a decline in risk with distance from transmitters.
Dolk H et al. · 1997
Researchers conducted a small-area study of cancer incidence from 1974 to 1986 around the Sutton Coldfield TV and FM radio transmitter in England. They used national cancer registration data and 1981 census data, calculating expected cancers with indirect standardization stratified by socioeconomic index. Adult leukemia risk within 2 km was 1.83 (95% CI 1.22-2.74) and declined significantly with distance (p=0.001), with similar patterns for skin and bladder cancer.
Repacholi et al. · 1997
Researchers exposed female E mu-Pim1 transgenic mice to pulsed 900 MHz fields for two 30-minute periods per day for up to 18 months. Lymphoma risk was significantly higher in exposed mice than in controls (OR = 2.4, P = 0.006). Follicular lymphomas were the major contributor to the increased tumor incidence.
Penafiel LM, Litovitz T, Krause D, Desta A, Mullins JM · 1997
Hocking B, Gordon IR, Grain HL, Hatfield GE · 1997
Researchers compared cancer incidence and mortality from 1972 to 1990 in nine municipalities, three of which surround TV towers and six of which are further away. Among children, the rate ratio for leukaemia incidence was 1.58 and for mortality it was 2.32. Brain cancer incidence and mortality were not increased. The researchers found an association between increased childhood leukaemia incidence and mortality and proximity to TV towers.
Unknown authors · 1996
The researchers investigated whether 60-Hz magnetic fields act at the cellular level to produce gene expression changes that can result in neoplastic transformation. Twenty-four hour exposure to 200 microT continuous magnetic fields produced negative results in Syrian hamster embryo cells and C3H/10T1/2 murine fibroblasts, with or without a chemical promoter. Extensive coded and uncoded analyses found no magnetic field effect on gene expression in human HL60 cells. No MF-induced changes in ornithine decarboxylase expression were observed in C3H/10T1/2 cells under the same exposure conditions.
Unknown authors · 1996
Unknown authors · 1996
Researchers investigated interactions of weak ELFMFs with primitive haemopoietic cells in vitro using the multipotential progenitor cell line FDCP-mix(A4). They determined proliferative activity and clonogenic potential under optimal and sub-optimal growth conditions with exposures to ambient laboratory ELFMFs or three other ELFMF regimes including nulled fields, Ca2+-ion cyclotron resonance at 50 Hz, and vertical 50 Hz fields of 6 muT(RMS). Using exposures of 1, 4, 7 and 21 days, they found no significant alteration of growth rate, cell-cycle state or clonogenic efficiency.
Unknown authors · 1996
Exposure of breast cancer cells to 12 mG, 1 G, or 9 G 60-Hz electromagnetic fields failed to stimulate Cdk2 or cyclin B1-cdc2 activity or cyclin D1 synthesis. Simultaneous co-exposure to 60-Hz fields and chemical promoters did not enhance Cdk2 activation beyond the effect of the chemical promoter alone. Estrogen and xenoestrogens stimulated estrogen receptor binding to the estrogen receptor element, but EMF did not.
Grayson JK · 1996
A nested case-control study investigated electromagnetic field exposures and brain tumor risk in the US Air Force. Cumulative extremely low frequency and radiofrequency/microwave exposures were estimated from a job-exposure matrix, and ionizing radiation exposures came from personal dosimetry records. Nonionizing electromagnetic field exposure showed a small excess risk with extremely low frequency OR 1.28 (95% CI 0.95-1.74) and radiofrequency/microwave OR 1.39 (95% CI 1.01-1.90), while ionizing radiation had OR 0.58 (95% CI 0.22-1.52). Military rank was consistently associated with brain tumor risk, with officers having OR 2.11 (95% CI 1.48-3.01) versus enlisted men and senior officers OR 3.30 (95% CI 1.99-5.45) versus all others.
Tynes T, Hannevik M, Andersen A, Vistnes AI, Haldorsen T · 1996
The Norwegian cohort consisted of 2,619 women certified as radio and telegraph operators between 1920 and 1980. Cancer incidence was analyzed using the standardized incidence ratio with the Norwegian female population as the comparison group. The standardized incidence ratio for all cancers was 1.2, while breast cancer showed an excess risk with an SIR of 1.5. A nested case-control analysis found an association between breast cancer in women aged 50 and older and shift work. After adjusting for fertility factors, the rate ratio for breast cancer associated with being a radio and telegraph operator was 1.5 compared to all Norwegian women born 1935 or later.
Szmigielski, S · 1996
Researchers compared cancer morbidity between occupationally exposed and non-exposed personnel using observed and expected rates to calculate an observed/expected ratio. The overall cancer morbidity rate was 119.1 per 100 000 annually in exposed personnel versus 57.6 in non-exposed, yielding an OER of 2.07 (P < 0.05). Higher rates were seen for alimentary tract neoplasms (OER = 3.19–3.24), brain tumours (OER = 1.91), and haemopoietic/lymphatic malignancies (OER = 6.31).
Rothman KJ, Loughlin JE, Funch DP, Dreyer NA · 1996
Researchers conducted a record-based mortality surveillance of a cohort of more than 250,000 portable and mobile telephone customers during 1994. Age-specific mortality rates were similar for users of the two types of telephones. For customers with accounts at least 3 years old, the mortality rate ratio for portable versus mobile telephone users was 0.86 with a 90% confidence interval of 0.47 to 1.53.
