Research relevant to EMF exposure in children - baby monitors, tablets, school WiFi, and wearables.
## Children's EMF Exposure: Understanding the Unique Risks Children face a fundamentally different EMF landscape than adults. Their developing nervous systems absorb radiation at rates up to 10 times higher than adult brains, according to research from France's National Frequency Agency. Yet the devices surrounding our kids today - from baby monitors broadcasting all night to tablets held inches from developing brains - weren't designed with children's unique vulnerabilities in mind.
Pologea-Moraru R, Kovacs E, Iliescu KR, Calota V, Sajin G · 2002
Researchers studied the effects of low-power microwaves at 2.45 GHz on the membrane fluidity of rod photoreceptor cells. The researchers expected the retina to be very sensitive to microwave irradiation due to the polar character of photoreceptor cells and high water content.
Miyakoshi, J., Yoshida, M., Tarusawa, Y., et al. · 2002
Unknown authors · 2002
The paper compares maximum allowable powers for cellular telephones at 835 and 1900 MHz under ANSI/IEEE, ICNIRP, and a proposed IEEE modification. It shows the ANSI/IEEE guideline is the most conservative, ICNIRP allows 2.5-3 times higher maximum radiated power, and the proposed modification allows up to 50% higher power. Peak 1 g SAR in smaller head models is up to 56% higher at 1900 MHz and up to 20% higher at 835 MHz than in larger models. Plastic ear models yield SARs up to two or more times smaller than realistic anatomic models, and a 2 mm thin shell phantom with lossy ear is proposed to match anatomic SARs within +/- 15%.
Liu X, Shen H, Shi Y, Chen J, Chen Y, Ji A. · 2002
Thompson CJ, Anderson V, Rowley JT. · 2002
The broad objective was to assess radiofrequency exposure limits, hazard thresholds, and safety factors using probabilistic risk analysis. Analysis of SAR variables including conductivity and permittivity of grey brain matter and radiated field strengths supported the hypothesis that SAR values are lognormally distributed. The probability that SAR exceeds a threshold was derived and shown to be very low for handset SARs relative to allowable standard limits. The analysis focused on peak radiofrequency SAR values in the brain from digital mobile telephones operating at approximately 900 MHz.
Trosic I, Busljeta I, Kasuba V, Rozgaj R. · 2002
Researchers exposed adult male Wistar rats to continuous 2450 MHz radiofrequency microwave radiation for 2 hours a day, 7 days a week, for up to 30 days, at a power density of 5–10 mW/cm2. Peripheral blood smears were examined for micronuclei in polychromatic erythrocytes as an indicator of genotoxicity. Micronuclei per 1000 PCEs were significantly increased after eight irradiation treatments compared with sham-exposed controls. The researchers noted that an adaptive mechanism in both erythrocytopoiesis and genotoxicity likely appeared during the subchronic irradiation treatment.
Bartsch H et al. · 2002
Researchers tested a GSM-like RF signal on mammary tumors induced by DMBA in female Sprague-Dawley rats as a model for human breast cancer. Three experiments were carried out under strictly standardized conditions using a GSM-like signal at 900 MHz pulsed at 217 Hz. The overall results showed no statistically significant effect of RF-field exposure on tumor latency, and cumulative tumor incidence was unaffected as well. The researchers concluded that low-level RF radiation does not appear to possess carcinogenic or cancer-promoting effects on DMBA-induced mammary tumors.
Bisht KS, Moros EG, Straube WL, Baty JD, Roti Roti JL · 2002
Researchers exposed C3H 10T½ cells to 835.62 MHz FDMA or 847.74 MHz CDMA modulated radiofrequency radiation to determine whether it caused micronuclei to form. Cells were exposed at power levels of 3.2 or 4.8 W/kg for CDMA and 3.2 or 5.1 W/kg for FDMA, for durations of 3, 8, 16, or 24 hours. In three repeat experiments, no exposure condition produced a significant increase in micronuclei compared to sham-exposed cells.
Braune S, Riedel A, Schulte-Monting J, Raczek J. · 2002
The study investigated the hypothesis that exposure to EMFs can increase sympathetic vasoconstrictor activity. Forty healthy young males and females underwent a single-blind, placebo-controlled protocol on two different days with randomized EMF and placebo periods. The EMF exposure was a GSM-like signal at 900 MHz, pulsed with 217 Hz, 2 W, delivered by a mobile phone on the right side of the head. Blood pressure, heart rate, cutaneous capillary perfusion, and serum levels of norepinephrine, epinephrine, cortisol, and endothelin were measured. Systolic and diastolic blood pressure increased about 5 mmHg during the protocol, but the changes were independent of EMF exposure.
de Pomerai DI, Dawe A, DjerbibL, Allan, Brunt G, Daniells C. · 2002
Researchers investigated growth rate and maturation proportion in C. elegans exposed to prolonged microwave fields at 25°C in synchronized cultures of wild-type larvae. Microwave exposure significantly increased growth rate by 8–11% and maturation proportion by 28–40%. Mild heat treatment at 28°C decreased growth rate by 10% and almost abolished maturation proportion, showing effects opposite to microwave exposure.
McNamee JP et al. · 2002
Human blood cultures were exposed to a 1.9 GHz continuous-wave radiofrequency field for 2 hours at SARs of 0.0, 0.1, 0.26, 0.92, 2.4, and 10 W/kg while temperature was maintained at 37.0 ± 0.5°C. DNA damage was measured immediately after exposure using the alkaline comet assay with four parameters, and micronucleus formation was assessed using the cytokinesis-block micronucleus assay. No evidence of increased primary DNA damage was detected at any SAR tested. There was no significant difference in micronucleus incidence between exposed cultures and sham controls at any SAR.
McNamee JP et al. · 2002
Blood cultures from human volunteers were exposed to an acute 1.9 GHz pulse-modulated radiofrequency (RF) field for 2 h using a series of six circularly polarized, cylindrical waveguides. Mean specific absorption rates (SARs) ranged from 0 to 10 W/kg and the temperature within the cultures during the exposure was maintained at 37.0 ± 0.5°C. DNA damage was quantified in leukocytes by the alkaline comet assay and the cytokinesis-block micronucleus assay. No evidence of increased primary DNA damage was detected by the comet assay and no significant differences in micronucleus frequency were found at any SAR tested.
McNamee JP et al. · 2002
Canadian researchers exposed human white blood cells to 1.9 GHz radiofrequency radiation (similar to cell phone frequencies) for 2 hours at various power levels up to 10 W/kg. They found no DNA damage in the cells compared to unexposed controls, using two different laboratory tests to detect genetic harm. This study suggests that short-term RF exposure at these levels does not cause immediate DNA breaks in immune cells.
Peyman A, Rezazadeh AA, Gabriel C · 2001
Researchers measured dielectric properties of ten rat tissues at six ages from 130 MHz to 10 GHz. Results showed a general decrease in dielectric properties with age. The decrease was more apparent in brain, skull, and skin tissues than in abdominal tissues. The variation was attributed to changes in water content and organic composition.
Koivisto M et al. · 2001
Researchers studied the influence of pulsed radiofrequency electromagnetic fields from digital GSM mobile phones (902 MHz, 217 Hz pulse modulation) on subjective symptoms in healthy subjects using two single-blind experiments. The results did not reveal any differences between exposure and non-exposure conditions. Exposure durations were about 60 minutes in Experiment 1 and 30 minutes in Experiment 2. Subjects rated symptoms including headache, dizziness, fatigue, itching or tingling of the skin, redness on the skin, and sensations of warmth on the skin.
S. Kwee, P. Raskmark & S. Velizarov · 2001
Researchers exposed transformed human epithelial amnion (AMA) cells to a microwave field simulating the GSM signal at 960 MHz for 20 minutes. The field generated a specific absorption rate (SAR) of 2.1 mW.kg−1 in the cells, and exposures were carried out at temperatures of 35, 37, and 40 ± 0.1°C. Higher amounts of Hsp-70 were found in exposed cells at 35 and 37°C compared with sham-exposed cells, while Hsp-27 showed no significant response. The researchers considered these effects athermal because the field strength was much lower than the safety standard for absence of heat generation by microwave fields.
Tattersall JE et al. · 2001
Vijayalaxmi et al. · 2001
Researchers exposed diluted peripheral blood from four healthy volunteers to 835.62 MHz RF radiation at SARs of 4.4 or 5.0 W/kg for 24 hours. Sham-exposed and gamma-irradiated (1.50 Gy) samples served as negative and positive controls, and lymphocytes were cultured for 48 or 72 hours to assess chromosomal aberrations, micronuclei, mitotic indices, and binucleate cells. No significant differences were found between RF-exposed and sham-exposed lymphocytes for any of the measured endpoints, while gamma radiation produced significantly different responses. The authors concluded there is no evidence for induction of chromosomal aberrations and micronuclei under these exposure conditions.
Vijayalaxmi et al. · 2001
Researchers exposed peripheral blood samples from four healthy nonsmoking volunteers to 847.74 MHz CDMA radiation at SARs of 4.9 or 5.5 W/kg for 24 hours. Sham-exposed and gamma-irradiated (1.5 Gy) samples served as controls. No significant differences were found between RF-exposed and sham-exposed lymphocytes in mitotic indices, frequencies of exchange aberrations, excess fragments, binucleate cells, or micronuclei. Gamma-irradiated lymphocytes showed significantly different responses for all indices compared to both RF-exposed and sham-exposed cells. The authors concluded there was no evidence for induction of chromosome aberrations and micronuclei under these exposure conditions.
Mausset A, de Seze R, Montpeyroux F, Privat A · 2001
Researchers injected rats with gamma-vinyl-GABA to increase GABA levels and then used immunohistochemistry and image analysis to measure cerebellar GABA content. They exposed rats to 900 MHz pulsed radiofrequency at 4 W/kg SAR and continuous waves at 32 W/kg SAR. Pulsed exposure selectively reduced the stained processes area in the Purkinje cell layer, while continuous exposure decreased optical density in all three cell layers. The authors noted that it is unknown whether these effects are partly due to local tissue heating.
Maes A, Collier M, Verschaeve L · 2001
Researchers investigated cytogenetic effects of 900 MHz radiofrequency fields using chromosome aberration and sister chromatid exchange frequency methods. They studied three exposure modes (continuous, pseudo-random, dummy burst) at power outputs from 0 to 50 W. Specific absorption rates ranged from 0 to 10 W/kg. The study examined effects of radiation alone and combined with mitomycin C and X-rays. Overall, no mutagenic or co-mutagenic effect was found.
Heikkinen P et al. · 2001
Researchers evaluated the effect of low-level RF radiation on cancer development initiated by ionizing radiation in mice. Two hundred female CBA/S mice were randomized into four equal groups at 3 to 5 weeks of age, and all groups except the cage-control group were exposed to ionizing radiation followed by RF radiation for 1.5 h per day, 5 days a week for 78 weeks. One group received continuous NMT-type RF radiation at 902.5 MHz and 1.5 W/kg SAR, another received pulsed GSM-type RF radiation at 902.4 MHz and 0.35 W/kg SAR, while controls were sham-exposed. RF radiation exposures did not significantly increase the incidence of any neoplastic lesion. The researchers concluded that the results do not provide evidence for cancer promotion by RF radiation from mobile phones.
Li L et al. · 2001
Researchers exposed murine C3H 10T(1/2) fibroblasts to radiofrequency fields at specific absorption rates of 3.2 to 5.1 W/kg. Cell cultures were exposed to 847.74 MHz CDMA and 835.62 MHz FDMA modulated radiations in radial transmission line irradiators with temperature regulated to 37.0 ± 0.3 °C. Using the alkaline comet assay, they found no statistically significant differences in comet moment or comet length between sham-exposed and exposed cells after 2, 4, or 24 hours of exposure, for both exponentially growing and plateau-phase cells. A 4-hour incubation after a 2-hour exposure also resulted in no significant changes in comet moment or comet length. The authors concluded that exposure at 37°C up to 5.1 W/kg did not induce measurable DNA damage.
Unknown authors · 2001
Researchers exposed mouse cells to cell phone radiation at power levels of 3-5 W/kg for up to 24 hours and found no DNA damage using sensitive laboratory tests. The study used both CDMA and FDMA signals similar to early cell phone networks. Temperature was carefully controlled to isolate radiation effects from heating.
Sykes PJ, McCallum BD, Bangay MJ, Hooker AM, Morley AA. · 2001
Researchers studied the effect of pulsed 900 MHz radiofrequency radiation at 4 W/kg on somatic intrachromosomal recombination in the spleen of pKZ1 mice. Mice were exposed daily for 30 minutes to 900 MHz fields for 1, 5, or 25 days, and spleen sections were screened for DNA inversion events three days after the last exposure. There was no significant difference between control and treated groups in the 1- and 5-day exposure groups, but a significant reduction in inversions was found in the 25-day group.