Braune, S, Wrocklage, C, Raczek, J, Gailus, T, Lucking, CH · 1998
German researchers exposed 10 healthy volunteers to GSM 900 MHz cell phone radiation for 35 minutes while continuously monitoring their blood pressure and heart rate. They found that resting blood pressure increased during exposure to the phone's electromagnetic field compared to a placebo condition. This suggests that even short-term exposure to cell phone radiation can affect cardiovascular function in healthy individuals.
Kwee S, Raskmark P · 1998
Researchers exposed human cells to 960 MHz microwave radiation (similar to early cell phone frequencies) at different power levels and durations to see how it affected cell growth. They found that microwave exposure consistently reduced cell proliferation compared to unexposed control cells, with stronger fields requiring less exposure time to achieve maximum effects. This suggests that radiofrequency radiation can directly interfere with normal cellular processes in a dose-dependent manner.
Malyapa RS et al. · 1998
Researchers exposed rats to microwave radiation at 2450 MHz (the same frequency used in microwave ovens) for 2 hours to test whether it causes DNA breaks in brain cells. They found no DNA damage in either the brain's cortex or hippocampus regions, contradicting an earlier study that reported such damage. This suggests that short-term exposure to this type of microwave radiation at moderate levels may not harm brain cell DNA.
Mann et al. · 1998
Researchers exposed healthy volunteers to 900 MHz electromagnetic fields (similar to older cell phones) while they slept and measured hormone levels throughout the night. They found a small, temporary increase in cortisol (stress hormone) right after exposure began, but no effects on growth hormone, reproductive hormones, or melatonin. The study suggests our bodies may quickly adapt to this type of EMF exposure.
Repacholi et al. · 1997
Scientists exposed genetically cancer-prone mice to 900 MHz radiofrequency fields (similar to cell phone signals) for 30 minutes twice daily for up to 18 months. The exposed mice developed lymphoma (a type of cancer) at 2.4 times the rate of unexposed mice. This suggests that cell phone-type radiation may accelerate cancer development in those already genetically susceptible.
Penafiel LM, Litovitz T, Krause D, Desta A, Mullins JM · 1997
Scientists exposed mouse cells to 835 MHz microwaves and found that pulsed signals (like those from digital phones) increased a growth-related enzyme by up to 90%, while steady signals showed little effect. This suggests the signal pattern, not just power level, influences biological responses.
Persson BRR, Salford LG, Brun A · 1997
Researchers exposed rats to 915 MHz microwave radiation (similar to cell phone frequencies) for periods ranging from 2 minutes to 16 hours and examined whether this damaged the blood-brain barrier, a critical protective shield that prevents toxins from entering brain tissue. They found that 39% of exposed rats showed abnormal leakage in their blood-brain barrier compared to only 17% of unexposed control rats. This suggests that wireless communication frequencies can compromise the brain's natural protective barrier, potentially allowing harmful substances to reach brain cells.
Malyapa RS et al. · 1997
Researchers exposed mouse and human cells to cell phone frequencies (835-847 MHz) for up to 24 hours at power levels similar to phone use to see if the radiation damaged DNA. Using a sensitive test called the comet assay, they found no DNA damage in the exposed cells compared to unexposed control cells. This suggests that cell phone radiation at typical exposure levels may not directly break DNA strands in laboratory conditions.
Roschke, J, Mann, K · 1997
German researchers exposed 34 healthy men to cell phone radiation (900 MHz) for 3.5 minutes while measuring their brain activity with EEG sensors. They found no detectable changes in brain wave patterns during the short exposure period compared to when the phone was turned off. This suggests that brief cell phone use may not immediately alter brain electrical activity in awake, healthy adults.
Malyapa RS et al. · 1997
Researchers exposed lab-grown cells to microwave radiation at 2450 MHz (the same frequency used in microwave ovens and older WiFi) for up to 24 hours to see if it would damage DNA. Using a highly sensitive test called the comet assay, they found no DNA damage at either exposure level tested. This contradicted earlier studies that suggested microwave radiation could break DNA strands in brain cells.
Ivaschuk OI et al. · 1997
Researchers exposed rat nerve cells to cell phone radiation at 836.55 MHz (the frequency used by early digital cell phones) to see if it would affect the activity of genes called c-fos and c-jun, which help control cell growth and responses to stress. They found mostly no effects, except for a 38% decrease in c-jun gene activity at the highest exposure level of 9 mW/cm². This suggests that cell phone radiation may have subtle effects on nerve cell gene expression, but only at relatively high exposure levels.
Stagg RB, Thomas WJ, Jones RA, Adey WR · 1997
Researchers exposed brain cells (both normal and cancerous glioma cells) to cell phone-like radiofrequency radiation at 836.55 MHz for 24 hours to see if it would promote tumor growth by affecting DNA synthesis. While they found small increases in DNA activity in some cancer cell experiments, this didn't translate to actual increased cell growth or proliferation in either normal or cancerous cells.
Vijayalaxmi et al. · 1997
Researchers exposed cancer-prone mice to 2450 MHz radiofrequency radiation (the same frequency used in microwave ovens and some WiFi) for 20 hours daily over 18 months to test whether it causes DNA damage. They measured micronuclei - tiny fragments that indicate genetic damage - in blood and bone marrow cells. The study found no significant difference in DNA damage between exposed and unexposed mice, suggesting this level of RF exposure did not cause detectable genetic harm.
Gos, P, Eicher, B, Kohli, J, Heyer, WD · 1997
Researchers exposed yeast cells (Saccharomyces cerevisiae) to extremely high frequency electromagnetic fields around 41.7 GHz at very low power levels to see if the radiation affected how quickly the cells divided. After careful testing with proper controls, they found no significant differences in cell division rates between exposed and unexposed yeast. This contradicts some earlier studies that claimed to find biological effects from similar EMF exposures.
Donnellan M, McKenzie DR, French PW · 1997
Researchers exposed immune cells called mast cells to 835 MHz radiofrequency radiation (similar to cell phone frequencies) for 20 minutes three times daily over a week. The exposed cells showed increased DNA synthesis, altered cell shape, and enhanced release of inflammatory substances compared to unexposed cells. These cellular changes persisted for at least a week after the radiation exposure ended, suggesting the effects may trigger lasting biological responses.
Donnellan M, McKenzie DR, French PW. · 1997
Researchers exposed immune cells called mast cells to cell phone radiation at 835 MHz for 20 minutes, three times daily for a week. They found that starting on day four, the cells began growing faster, changed shape, and became more reactive to chemical triggers. What's particularly concerning is that these changes persisted for at least a week after the radiation exposure ended, suggesting the effects may be long-lasting.
Jensh RP · 1997
Pregnant rats exposed to microwave radiation at cell phone and microwave oven frequencies showed concerning effects in offspring. The highest frequency (6000 MHz) caused delayed development, reduced birth weight, and altered brain function, suggesting certain microwave frequencies may affect developing brains.
Vijayalaxmi, Mohan, N, Meltz, ML, Wittler, MA, · 1997
Researchers exposed human blood cells to microwave radiation at 2450 MHz (the same frequency used in microwave ovens and WiFi) for 90 minutes to see if it would damage DNA or affect cell growth. They found no genetic damage, chromosome breaks, or changes in how fast the cells multiplied compared to unexposed cells. This suggests that short-term exposure to this type of radiation at these power levels may not immediately harm human blood cells.
Vollrath L, Spessert R, Kratzsch T, Keiner M, Hollmann H · 1997
German researchers exposed rats and hamsters to 900 MHz radio frequency fields (similar to early cell phones) for up to 6 hours to see if it would affect their pineal glands, which produce the sleep hormone melatonin. They found no changes in melatonin production or pineal gland structure at any exposure level tested. This suggests that short-term RF exposure at these levels doesn't disrupt the body's natural sleep-wake cycle regulation.
Vorobyov VV, Galchenko AA, Kukushkin NI, Akoev IG · 1997
Russian scientists exposed rats to weak cell phone-like radiation (945 MHz) for 10 minutes and found immediate changes in brain wave patterns between left and right brain hemispheres within 20 seconds. This suggests microwave radiation can directly interfere with normal brain electrical activity.
Salford LG, Brun A, Persson BRR · 1997
Researchers injected brain tumor cells into 154 pairs of rats, then exposed half to 915 MHz microwaves (the frequency used by early cell phones) for 7 hours daily over 2-3 weeks while keeping the other half as controls. They found no difference in tumor growth between exposed and unexposed rats, suggesting that microwave exposure did not accelerate existing brain tumors in this particular experimental setup.
Nakamura H, Seto T, Nagase H, Yoshida M, Dan S, Ogino K. · 1997
Japanese researchers exposed pregnant and non-pregnant rats to microwave radiation at 2450 MHz (the same frequency used by microwave ovens and WiFi) for 90 minutes at 10 mW/cm². They found that pregnant rats showed significant immune system suppression, with reduced natural killer cell activity in the spleen, while non-pregnant rats showed no immune changes. The study reveals that pregnancy makes organisms more vulnerable to microwave radiation effects.
Lai H, Carino MA, Singh NP · 1997
Researchers exposed rats to microwave radiation at 2.45 GHz for 2 hours and found significant DNA double strand breaks in brain cells. When they gave rats naltrexone (a drug that blocks the body's natural opioids), it partially prevented the DNA damage. This suggests that microwave radiation triggers the body's opioid system, which then contributes to genetic damage in brain tissue.
Lai, H, Carino, MA, Singh, NP, · 1997
Researchers exposed rats to 2.45 GHz microwave radiation (the same frequency used in WiFi and microwave ovens) for 2 hours and found it caused DNA double strand breaks in brain cells. When they gave the rats naltrexone, a drug that blocks the body's natural opioids, it partially prevented this DNA damage. This suggests the body's own opioid system plays a role in how microwave radiation damages DNA in brain cells.
Ryan KL, Walters TJ, Tehrany MR, Lovelace JD, Jauchem JR · 1997
Researchers exposed rats of different ages to 35 GHz microwave radiation until death to study whether age affects how the body responds to microwave heating. They found that young, middle-aged, and older rats all showed identical patterns of rising body temperature and heart rate during exposure, with no age-related differences in survival time. This suggests that age doesn't change how mammals respond to intense microwave heating.
