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.
Gandhi OP, Lazzi G, Tinniswood A, Yu QS, · 1999
Researchers compared computer calculations with actual measurements to determine how much radiofrequency energy cell phones deposit in human tissue (called SAR). They tested phones operating at cellular frequencies and found SAR levels ranged dramatically from 0.13 to 5.41 watts per kilogram, with some older-technology phones exceeding current safety limits of 1.6 W/kg unless antennas were carefully designed and positioned away from the head.
Novoselova, EG, Fesenko, EE, Makar, VR, Sadovnikov, VB · 1999
Russian researchers exposed mice to very low-level microwave radiation (similar to what cell towers emit) for 5 hours and found it significantly boosted immune system activity. The microwaves increased production of tumor necrosis factor (TNF), a key immune signaling molecule, in immune cells called macrophages and T-cells. This immune activation lasted for at least 3 days after exposure and was enhanced when mice were given antioxidant nutrients.
Morrissey JJ et al. · 1999
Researchers exposed mice to 1.6-GHz radiofrequency signals (similar to satellite phone frequencies) for one hour to see if it affected brain activity. They found that brain changes only occurred at exposure levels 6-30 times higher than current safety limits for cell phones, and these changes appeared to be caused by tissue heating rather than direct effects from the radiation itself.
Trosic I, Matausicpisl M, Radalj Z, Prlic I, · 1999
Researchers exposed rats to microwave radiation at 2450 MHz for two hours daily over 30 days. The exposed rats showed decreased white blood cells and increased red blood cells compared to controls, indicating the radiation affected their immune and blood systems.
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.
Fesenko EE et al. · 1999
Russian researchers exposed mice to extremely low-power microwave radiation (8.15-18 GHz at 1 microW/cm²) for 24-72 hours and found their natural killer cells became 130-150% more active. Natural killer cells are immune system defenders that destroy cancer cells and virus-infected cells. The immune boost lasted 24 hours after exposure ended, but shorter exposures of 3-5 hours showed no effect.
Fesenko EE et al. · 1999
Russian researchers exposed mice to weak microwave radiation (8.15-18 GHz) for 24-72 hours and found their natural killer cells - immune cells that fight cancer and infections - became 130-150% more active. The immune boost lasted at least 24 hours after exposure ended, but shorter exposures of just a few hours showed no effect.
E.G Novoselova, E.E Fesenko, V.R Makar, V.B Sadovnikov · 1999
Researchers exposed mice to extremely low-power microwave radiation (8.15-18 GHz) for 5 hours and found it actually stimulated their immune systems, increasing production of immune signaling molecules and enhancing T cell activity. The immune boost was further enhanced when mice were given antioxidant nutrients like vitamin E and beta-carotene. This suggests that very low-level microwave exposure might trigger beneficial immune responses rather than suppress immunity.
Adey WR et al. · 1999
Researchers exposed pregnant rats and their offspring to cell phone radiation (836 MHz) for 24 months to study brain tumor development. Surprisingly, the radiation-exposed animals showed fewer brain tumors than unexposed controls, both naturally occurring tumors and those induced by a cancer-causing chemical. This unexpected protective effect was most pronounced in rats that died early in the study, where radiation exposure reduced chemically-induced brain tumors by a statistically significant amount.
Schonborn F, Burkhardt M, Kuster N · 1998
Researchers used computer simulations to compare how much cell phone radiation is absorbed by children's heads versus adults' heads at 900 MHz and 1,800 MHz frequencies. They found no significant differences in radiation absorption between children and adults, contradicting earlier studies that suggested children absorb more radiation. This finding has important implications for safety standards, which are currently based only on adult head models.
Wagner, P, Roschke, J, Mann, K, Hiller, W, Frank, C · 1998
German researchers monitored the sleep patterns of 24 healthy men using brain wave measurements while exposing them to cell phone-like radiofrequency signals (900 MHz GSM signals). The study found no statistically significant changes in sleep quality, REM sleep duration, or brain wave patterns during EMF exposure. The researchers noted their failure to replicate previous findings might indicate that EMF effects on sleep depend on the specific exposure dose.
Malyapa RS et al. · 1998
Researchers exposed rats to 2450 MHz microwave radiation (the same frequency used in microwave ovens and some WiFi devices) for 2 hours to see if it would damage DNA in brain cells, as a previous study had suggested. They found no DNA damage in either the brain's cortex or hippocampus regions, contradicting the earlier research. This study suggests that short-term exposure to this type of radiation at moderate levels may not cause immediate genetic damage to brain cells.
Imaida K et al. · 1998
Japanese researchers exposed rats to 929.2 MHz cell phone radiation for 90 minutes daily over 6 weeks to test whether the radiation could promote liver cancer development. The study used relatively high SAR levels (up to 7.2 W/kg) and found no difference in pre-cancerous liver lesions between exposed and unexposed rats. This suggests that cell phone radiation at these levels does not accelerate liver cancer progression in this animal model.
Imaida et al. · 1998
Researchers exposed rats to 1.439 GHz radiofrequency radiation (the type used in Japanese cell phones) to see if it would promote liver cancer development. Despite using exposure levels up to 1.91 W/kg and finding evidence of biological stress (increased stress hormones), the radiation did not increase cancer-promoting changes in the liver. This suggests that cell phone radiation at these levels does not accelerate liver cancer progression in this animal model.
Frei et al. · 1998
Researchers exposed 100 mice genetically prone to breast cancer to microwave radiation at 2450 MHz (the same frequency used in microwave ovens and early WiFi) for 78 weeks, 20 hours per day. They found no difference in cancer rates between exposed mice (38%) and unexposed mice (30%), and no difference in how quickly tumors developed or grew. This suggests that chronic exposure to this specific level of microwave radiation did not increase breast cancer risk in these cancer-prone animals.
Walters TJ et al. · 1998
Scientists exposed rats to 2.06 GHz microwave radiation and measured brain temperatures. High-power microwaves created uneven heating patterns, with some brain areas heating 2-2.5 times faster than nearby regions. This uneven heating didn't occur with conventional heat sources like warm water.
Dmoch A, Moszczynski P · 1998
Polish researchers studied immune system function in workers exposed to microwave radiation from TV transmission and satellite communication equipment (6-12 GHz frequencies). They found several changes in immune cell populations and antibody levels, including increased immunoglobulins (infection-fighting proteins) and altered ratios of different white blood cell types. However, the authors concluded these changes had no clinical significance, meaning they didn't appear to cause actual health problems.
Mickley GA, Cobb BL · 1998
Researchers exposed rats to microwave radiation at levels that caused significant body heating and found it disrupted their ability to distinguish between familiar and new objects - a key indicator of working memory function. However, rats that had been previously exposed to the heating developed a tolerance that protected them from both the temperature increase and memory problems. The study suggests that microwave-induced heating can impair cognitive function, but the brain may adapt to protect itself from repeated exposures.
Pavel A, Ungureanu CE, Bara II, Gassner P, Creanga DE · 1998
Romanian researchers exposed wheat seeds to low-intensity 9.75 GHz microwaves and examined the genetic material under microscopes. They found multiple types of DNA damage including chromosome fragments, delayed chromosomes, and other cellular abnormalities that didn't appear in unexposed control seeds. This demonstrates that even low-intensity microwave radiation can cause measurable genetic damage in living organisms.
Novoselova ET, Fesenko EE. · 1998
Russian researchers exposed mice to extremely weak microwave radiation (8.15-18 GHz at 1 microW/cm²) and found it significantly increased production of tumor necrosis factor in immune cells called macrophages. Tumor necrosis factor is a key protein that triggers inflammation and immune responses in the body. This suggests that even very low-power microwave radiation can alter immune system function.
Novoselova ET, Fesenko EE. · 1998
Russian researchers exposed mice to extremely weak microwave radiation (8.15-18 GHz) at power levels 1,000 times lower than cell phones. The exposure significantly increased production of tumor necrosis factor, a key immune protein, suggesting even very low-level microwaves can alter immune function.
Nakamura et al. · 1998
Researchers exposed pregnant rats to microwave radiation at 2.45 GHz for 90 minutes and found it suppressed natural killer cells, which fight infections and cancer. This immune suppression occurred through the body's opioid system, showing microwave exposure can weaken immunity during pregnancy when protection is most critical.
Phillips et al. · 1998
Researchers exposed immune cells to cell phone radiation at different power levels and measured DNA damage. They found that very low levels of radiation actually reduced DNA damage, while slightly higher levels increased it. This suggests that cell phone radiation can affect DNA in ways that depend on the specific exposure level.
Phillips et al. · 1998
Researchers exposed immune system cells to radiofrequency radiation from cell phone signals at extremely low power levels for 2 to 21 hours. They found that very low exposures actually reduced DNA damage, while slightly higher exposures increased DNA breaks in the cellular genetic material. This suggests that even minimal RF radiation can alter DNA integrity in immune cells, though the effects varied depending on the specific exposure level.
