Unknown authors · 1999
Researchers exposed human leukemia T-cells to 50 Hz magnetic fields (the same frequency as electrical power lines) and measured calcium oscillations inside the cells. They found that magnetic field exposure reduced these calcium signals in a dose-dependent manner - the stronger the field, the greater the reduction. This matters because calcium signaling is crucial for immune cell function and communication.
Unknown authors · 1999
Researchers studied 142 male electric utility workers in Colorado to see how 60 Hz magnetic fields affect melatonin, a hormone that regulates sleep. Workers exposed to temporally stable magnetic fields had reduced levels of melatonin metabolites in their urine, but only when they also had low light exposure at work. This suggests that power line frequency magnetic fields can disrupt the body's natural hormone production.
Unknown authors · 1999
Researchers exposed human breast cells to 60 Hz magnetic fields (the same frequency as household electricity) at various strengths for up to 24 hours to see if EMF exposure would alter cancer-related genes. The study found no significant changes in gene expression for key cancer markers like c-myc, p53, and others, suggesting 60 Hz magnetic fields don't promote breast cancer through genetic mechanisms.
Unknown authors · 1999
Researchers measured electrical fields around high-voltage power lines and found they create charged particles (ions) that can travel over 500 meters from the lines. These ions change how air pollution particles behave, potentially making them stick more to your lungs when you breathe them in.
Unknown authors · 1999
University of Bristol researchers found that high voltage power lines create electric fields that dramatically increase the deposition of airborne pollutants on human skin. Using radioactive marker particles, they measured 2-3 times more pollutant particles depositing on surfaces under 400 kV power lines compared to areas away from the lines. This means people living or working near power lines face significantly higher exposure to whatever air pollution is present.
Unknown authors · 1999
Researchers studied people who report symptoms they believe are triggered by electrical devices, a condition called electromagnetic hypersensitivity (EHS). They surveyed workers at a telecommunications company and patients at a medical clinic to identify symptom patterns. The study found that skin symptoms, rather than nervous system symptoms, were the primary characteristic of reported EHS.
Unknown authors · 1999
Canadian researchers studied 399 children with leukemia and 399 healthy controls, measuring their exposure to power line electric and magnetic fields through personal monitors, home measurements, and wire coding. The study found no increased risk of childhood leukemia from EMF exposure, with odds ratios close to 1.0 across all measurements. This large case-control study provides evidence against a strong link between power-frequency EMF and childhood leukemia.
Unknown authors · 1999
Researchers exposed 100 female rats to power line frequency magnetic fields (50-60 Hz) for 26 weeks after chemically inducing breast cancer to test whether EMF promotes tumor growth. The magnetic field exposure actually decreased cancer rates compared to unexposed rats, contradicting the hypothesis that these frequencies promote breast cancer.
Unknown authors · 1999
Researchers studied 24 healthy young men sleeping in laboratory conditions with 60 Hz magnetic field exposure at power line frequencies. Intermittent exposure significantly disrupted sleep quality, reducing total sleep time and REM sleep while increasing lighter sleep stages. Participants also reported feeling less rested the next morning.
Unknown authors · 1999
Swedish researchers exposed human leukemia cells to 50 Hz magnetic fields (the frequency used in European power systems) and measured calcium activity inside the cells. They found that magnetic field exposure reduced calcium oscillations in a dose-dependent manner, with stronger fields causing greater disruption. This matters because calcium signaling controls many essential cellular functions including immune responses.
Unknown authors · 1999
Researchers studied 142 male electric utility workers in Colorado and found that exposure to temporally stable 60 Hz magnetic fields reduced their excretion of a melatonin metabolite, indicating suppressed melatonin production. The effect was strongest in workers with low workplace light exposure, suggesting magnetic fields can disrupt the body's natural hormone cycles.
Unknown authors · 1999
This Canadian study examined 201 children with leukemia and 406 healthy controls, measuring magnetic field exposure in their homes. Children under 6 with magnetic field exposure above 0.15 microT had a 3.45 times higher risk of developing leukemia. The strongest associations occurred with exposures during the earliest years of life.
Unknown authors · 1999
German researchers exposed female rats to power line frequency magnetic fields (50 Hz, 100 microTesla) for 27 weeks while inducing breast cancer with a chemical carcinogen. The magnetic field exposure significantly increased mammary tumor development by 190% at 13 weeks and final tumor rates reached 64.7% in exposed rats versus 50.5% in controls.
Unknown authors · 1999
Researchers exposed human breast cells to 60 Hz magnetic fields at various strengths (0.1 to 10 Gauss) for up to 24 hours to test whether power line frequencies could trigger cancer-related gene changes. The study found no significant alterations in key cancer genes like c-myc, p53, and others, suggesting 60 Hz fields don't promote breast cancer through direct genetic mechanisms.
Unknown authors · 1999
Researchers exposed 400 female rats to 50 Hz and 60 Hz magnetic fields for 13 weeks after chemically inducing breast cancer with DMBA. The magnetic fields at 1-5 gauss strength showed no effect on tumor development, size, or timing compared to unexposed controls.
Unknown authors · 1999
Researchers exposed human blood cancer cells (HL-60) to 60 Hz magnetic fields for 2 hours and found that 1 milliTesla exposure triggered cellular stress responses, including production of heat shock proteins. Lower exposure levels (0.1 mT) showed no effect, suggesting a threshold for biological impact.
Unknown authors · 1999
University of Bristol researchers found that high voltage power lines increase exposure to airborne pollutants by 2-3 times through enhanced deposition on the human body. The 50 Hz electric fields from transmission lines attract radioactive particles and other aerosols, causing them to stick more readily to skin and surfaces underneath the lines.
Unknown authors · 1999
The UK Childhood Cancer Study examined 2,226 children to determine if power line magnetic fields increase cancer risk. Researchers found no increased risk of childhood leukemia, brain tumors, or other cancers from magnetic field exposure. This large population study contradicts earlier research suggesting links between power line EMF and childhood cancer.
Vijayalaxmi et al. · 1999
Researchers exposed mice to ultra-wideband electromagnetic radiation (a type of wireless signal) for 15 minutes and then examined their blood and bone marrow cells for signs of genetic damage. They found no evidence that the radiation caused DNA damage or other cellular harm compared to unexposed control mice. This suggests that short-term exposure to this specific type of electromagnetic radiation at the tested intensity may not pose immediate genetic risks.
Tuschl et al. · 1999
Researchers measured high-frequency electromagnetic field exposure among physiotherapists operating medical diathermy devices and found exposure levels that considerably exceeded recommended limits. Despite this chronic occupational exposure, blood tests revealed no statistically significant differences in immune system function between exposed workers and unexposed controls. All immune parameters remained within normal ranges for both groups.
Nelson BK, Snyder DL, Shaw PB · 1999
Researchers exposed pregnant rats to radiofrequency radiation combined with salicylic acid (aspirin-like compound) to see if RF radiation would worsen birth defects caused by the chemical. Unlike previous studies with other chemicals, they found no evidence that RF radiation made salicylic acid more harmful to developing fetuses. This suggests that RF radiation's ability to enhance chemical toxicity may depend on the specific chemical involved.
Mineta M et al. · 1999
Japanese researchers exposed bacteria commonly used in genetic testing to extremely strong magnetic fields (6.3 Tesla) combined with radiofrequency radiation similar to what's found in MRI machines for up to one hour. They found no increase in genetic mutations compared to unexposed bacteria, suggesting that MRI-level electromagnetic exposures don't cause DNA damage in this bacterial model.
Miller SA, Bronson ME, Murphy MR · 1999
Researchers exposed rats to ultrawideband (UWB) electromagnetic pulses while inducing seizures with a drug called pentylenetetrazol to test whether these high-power, ultrashort electromagnetic pulses could cause brain tissue damage. They found no effect of UWB exposure on seizure activity compared to unexposed animals. This suggests that UWB radiation at the levels tested does not produce the kind of electromagnetic transients that would damage brain tissue.
Linz et al. · 1999
German researchers exposed isolated heart muscle cells from guinea pigs and rats to cell phone frequencies (900 MHz and 1800 MHz) to see if radio waves affected the cells' electrical activity. They found no significant changes to the heart cells' membrane potential, action potentials, or calcium and potassium currents even at exposure levels up to 880 mW/kg. The study suggests that cell phone radiation at these levels does not directly disrupt the basic electrical functions of heart muscle cells.
Li et al. · 1999
Researchers exposed human cells to 837 MHz microwave radiation (the frequency used by early cell phones) for 2 hours at power levels ranging from 0.9 to 9.0 W/kg. They measured levels of TP53, a critical protein that normally increases when cells are damaged and helps prevent cancer formation. The study found no changes in TP53 levels up to 48 hours after exposure, suggesting these microwave frequencies did not trigger the cellular damage response.
