motnje v razvoju (50 od skupno 1329 raziskav)
"Radiation exposure has long been a concern for the public, policy makers, and health researchers. Beginning with radar during World War II, human exposure to radio-frequency radiation (RFR) technologies has grown substantially over time. In 2011, the International Agency for Research on Cancer (IARC) reviewed the published literature and categorized RFR as a "possible" (Group 2B) human carcinogen. A broad range of adverse human health effects associated with RFR have been reported since the IARC review. In addition, three large-scale carcinogenicity studies in rodents exposed to levels of RFR that mimic lifetime human exposures have shown significantly increased rates of Schwannomas and malignant gliomas, as well as chromosomal DNA damage. Of particular concern are the effects of RFR exposure on the developing brain in children. Compared with an adult male, a cell phone held against the head of a child exposes deeper brain structures to greater radiation doses per unit volume, and the young, thin skull's bone marrow absorbs a roughly 10-fold higher local dose. Experimental and observational studies also suggest that men who keep cell phones in their trouser pockets have significantly lower sperm counts and significantly impaired sperm motility and morphology, including mitochondrial DNA damage. Based on the accumulated evidence, we recommend that IARC re-evaluate its 2011 classification of the human carcinogenicity of RFR, and that WHO complete a systematic review of multiple other health effects such as sperm damage. In the interim, current knowledge provides justification for governments, public health authorities, and physicians/allied health professionals to warn the population that having a cell phone next to the body is harmful, and to support measures to reduce all exposures to RFR."
"Although this study has some limitations, it leads us to this conclusion that higher-than-ever levels of maternal exposure to electromagnetic fields could be linked to offspring speech problems."
"This commentary addresses several unfounded criticisms about the design and results of the NTP study that have been promoted to minimize the utility of the experimental data on RFR for assessing human health risks. In contrast to those criticisms, an expert peer-review panel recently concluded that the NTP studies were well designed, and that the results demonstrated that both GSM- and CDMA-modulated RFR were carcinogenic to the heart (schwannomas) and brain (gliomas) of male rats."
"However, public exposure regulations in most countries continue to be based on the guidelines of the International Commission on Non-Ionizing Radiation Protection and Institute of Electrical and Electronics Engineers, which were established in the 1990s on the belief that only acute thermal effects are hazardous. Prevention of tissue heating by radiofrequency electromagnetic radiation is now proven to be ineffective in preventing biochemical and physiological interference. For example, acute non-thermal exposure has been shown to alter human brain metabolism by NIH scientists, electrical activity in the brain, and systemic immune responses. Chronic exposure has been associated with increased oxidative stress and DNA damage and cancer risk. Laboratory studies, including large rodent studies by the US National Toxicology Program and Ramazzini Institute of Italy, confirm these biological and health effects in vivo."
"Results from the present study concludes that the brain of 2 weeks aged mice was very sensitive to microwave exposure as observed immediately after exposure and during follow-up study at 6 weeks of age."
"Results showed an increased level of lipid peroxidation, decreased level of glutathione and protein after microwave exposure on both 0.25 and 11.25 day of gestation. Moreover, changes in cytoarchitechure of hippocampus and cerebellum of the brain and reduction in Purkinje cell number were observed statistically significant after microwave exposure from both 0.25 and 11.25 days of gestation. In conclusion, the degree of severity of damage in neonatal mice brain was much higher, when exposure started from 0.25 day of gestation compared to 11.25 days of gestation."
"These results indicate that interference with stem cell proliferation upon short-term exposure to an 1800 MHz electromagnetic field depends on the developmental stage of the brain."
"Several studies clearly demonstrate that EMF emitted by cell phones could affect a range of body systems and functions. Recent work has demonstrated that EMF inhibit the formation and differentiation of neural stem cells during embryonic development and also affect reproductive and neurological health of adults that have undergone prenatal exposure. The aim of this review is to discuss the developing CNS and explain potential impacts of EMF on this system."
"In conclusion, Wi-Fi-induced oxidative stress in the brain and liver of developing rats was the result of reduced GSH-Px, GSH and antioxidant vitamin concentrations. Moreover, the brain seemed to be more sensitive to oxidative injury compared to the liver in the development of newborns."
"In conclusion, although EMR exposure decreased the prolactin, estrogen, and progesterone levels in the plasma of maternal rats and their offspring, EMR-induced oxidative stress in the uteri of maternal rats increased during the development of offspring. Mobile phone- and Wi-Fi-induced EMR may be one cause of increased oxidative uterine injury in growing rats and decreased hormone levels in maternal rats."
"Based on this study, it is thought that chronic pre- and post-natal period exposure to wireless internet frequency of EMF may cause chronic kidney damages; staying away from EMF source in especially pregnancy and early childhood period may reduce negative effects of exposure on kidney."
"We found a significant association between either the call time (P=0.002) or history of mobile phone use (months used) and speech problems in the offspring (P=0.003)."
"These data support the hypothesis that long-term exposure of 50 Hz magnetic fields is a significant risk factor for neoplastic development and fertility in mice."
"The study results indicated that GSM-like RF-EMR (e.g. radiation from cell phones) was not as harmful to Xenopus embryos as might have been expected. However, the combined effects of GSM-like RF-EMR and NS on Xenopus embryos were more severe than the effect of RF-EMR or NS alone. In conclusion, the study results appear to suggest that the combined use of nicotine and cell phones might result in more pronounced detrimental effects on the health of smokers."
"Exposure to 2450 MHz EMF, particularly in the prenatal period, resulted in postnatal growth restriction and delayed puberty in female Wistar rats. Increased TOS and OSI values in the brain and ovary tissues can be interpreted as a sign of chronic stress induced by EMF. This is the first longitudinal study which investigates the effects of EMF induced by wireless internet on pubertal development beside growth."
"Histological and immunohistochemical examinations between the experimental and control groups showed that exposure to 2.45 GHz EMR for 2 h per day does not interfere with the development of teeth and surrounding tissues. However, there were alterations in the elemental composition of the teeth, especially affecting such oxidative stress-related elements as copper, zinc, and iron, suggesting that short-term exposure to Wi-Fi-induced EMR may cause an imbalance in the oxidative stress condition in the teeth of growing rats."
"We conclude that age-dependent RF-EMR study results, when considered in the context of developmental stage, indicate increased specific vulnerabilities in the young (fetus to adolescent), the elderly, and those with cancer. There appears to be at least one mechanism other than the known thermal mechanism causing different responses to RF-EMR depending upon the exposure parameters, the cell/physiological process involved, and according to age and health status. As well as personal health and quality-of-life impacts, an ageing population means there are economic implications for public health and policy."
"Children absorb more MWR than adults because their brain tissues are more absorbent, their skulls are thinner and their relative size is smaller. MWR from wireless devices has been declared a possible human carcinogen. Children are at greater risk than adults when exposed to any carcinogen. Because the average latency time between first exposure and diagnosis of a tumor can be decades, tumors induced in children may not be diagnosed until well into adulthood. The fetus is particularly vulnerable to MWR. MWR exposure can result in degeneration of the protective myelin sheath that surrounds brain neurons. MWR-emitting toys are being sold for use by young infants and toddlers. Digital dementia has been reported in school age children. A case study has shown when cellphones are placed in teenage girls’ bras multiple primary breast cancer develop beneath where the phones are placed."
"For SEPs, all components of PP group, P2, N2 components of Pr group and P1, P2, N2 components of Po group were delayed versus C group. As brain TBARS levels were significantly increased in Pr and Po groups, retina TBARS levels were significantly elevated in all experimental groups versus C group. In conclusion, alterations seen in evoked potentials, at least partly, could be explained by lipid peroxidation in the retina and brain."
"All exposure protocols resulted in an increase of apoptotic cell death (ACD) observed in egg chambers, even at very low electric field strengths. FM waves seem to have a stronger effect in ACD than continuous waves. Regarding intensity and temporal exposure pattern, EMF-biological tissue interaction is not linear in response. Intensity threshold for the induction of biological effects depends on frequency, modulation and temporal exposure pattern with unknown so far mechanisms. Given this complexity, translating such experimental data into possible human exposure guidelines is yet arbitrary."
"Our study results suggest that exposure to EMF in the prenatal period causes oxidative stress and histopathological changes in male rat pup heart tissue."
"The findings indicated cellular structural damage in the cochlea caused by radiofrequency radiation exposure during cochlear development in the rat model."
"RESULTS: ELF magnetic field shortens developmental time, increases viability and does not affect sex ratio of D. subobscura. No matter which developmental stage is exposed, ELF magnetic field significantly decreases locomotor activity of adult flies, but after exposure of just eclosed adults observed change lasts longer. CONCLUSIONS: Applied ELF magnetic field modifies fitness components and locomotor activity of D. subobscura. Observed effects can be attributed to the influence of magnetic field on different stages of development where the hormonal and nervous systems play important role in the control of examined parameters."
"Although cell proliferation and the percentages of neurons and astrocytes differentiated from eNSCs were not affected by 50 Hz ELF-EMF, the expression of genes regulating neuronal differentiation was altered. In conclusion, our results support that 50 Hz ELF-EMF induce molecular changes during eNSCs differentiation, which might be compensated by post-transcriptional mechanisms to support cellular homeostasis."
"It is concluded that exposure to EMF during the developmental period could affect both oocyte differentiation and folliculogenesis and may result in reduced fertility, by decreasing ovarian reservoir."
"In conclusion, Wi-Fi- and mobile phone-induced EMR caused oxidative damage by increasing the extent of lipid peroxidation and the iron level, while decreasing total antioxidant status, copper, and GSH values. Wi-Fi- and mobile phone-induced EMR may cause precocious puberty and oxidative kidney and testis injury in growing rats."
"Our findings led us to conclude that a low level of MW irradiation-induced oxidative stress not only suppresses implantation, but it may also lead to deformity of the embryo in case pregnancy continues. We also suggest that MW radiation-induced oxidative stress by increasing ROS production in the body may lead to DNA strand breakage in the brain cells and implantation failure/resorption or abnormal pregnancy in mice."
"By varying duration of exposure, the embryos were exposed to different doses of radiation, sacrificed at different periods of incubation and subjected to histological processing. On light microscopic study it was observed that developing neurons of dorsal root ganglion suffered a damage which was dose dependent and persisted in spite of giving the exposure-free period between two exposures."
"Consequently, it can be concluded that GSM-like RF radiation may induce biochemical changes by increasing free radical attacks to structural biomolecules in the rabbit as an experimental animal model."
"The radical pair mechanism and related cryptochromes (CRY) molecules have recently been identified in birds and other non-mammalian species, as a sensor of the geomagnetic field, involved in navigation. The hypothesis has to be tested in mammalian models. CRY, which is part of the molecular circadian clock machinery, is a ubiquitous protein likely to be involved in cancer cell growth and DNA repair. In summary, we now have some clues to test for a better characterization of the interaction between ALL and ELF MFs exposure."
"The RF exposure resulted in minor increases in formation of antibodies in brain tissue extract and the exposure did not appear to be pathological. In addition, a study was conducted to replicate a previous Soviet study on effects from the injection of blood serum from RF-exposed rats on pregnancy and foetal and offspring development of rats, using a similar animal model and protocol. Our results showed the same general trends as the earlier study, suggesting possible adverse effects of the blood serum from exposed rats on pregnancy and foetal development of intact rats, however, application of these results in developing exposure standards is limited."
"The International Oversight Committee (IOC) provided oversight on the conduct of the studies and was the firewall committee that dealt with the sponsors and researchers. This paper gives the IOC comments and conclusions on the differing results between the two studies."
"They were exposed to RFR (1800 MHz GSM; 14 V/m as reference level) for 15 min/day during 7 days. Malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were analyzed. MDA and 8-OHdG levels of non-pregnant and pregnant-RFR exposed animals significantly increased with respect to controls (p < 0.001, Mann-Whitney test). No difference was found in the newborns (p > 0.05, Mann-Whitney). There exist very few experimental studies on the effects of RFR during pregnancy. It would be beneficial to increase the number of these studies in order to establish international standards for the protection of pregnant women from RFR."
"RESULTS: (a) Mean developmental rate of exposed cohorts was reduced with respect to controls (0.43 vs. 0.48 stages/day, p < 0.001) starting from early larval stages; (b) Exposure increased the mean metamorphosis period of tadpoles by 2.4 days compared with the controls (p < 0.001); (c) Maturation rates of exposed and control tadpoles changed during maturation period; and (d) Important mortality, malformations or teratogenic effects were not observed in exposed matured tadpoles. CONCLUSION: A long-term exposure of X. laevis tadpoles to a relatively weak 50 Hz magnetic field causes a sub-lethal effect that slows down their larval developmental rate and delays their metamorphosis."
"Contrasting effects of EMF on the retinal histomorphology were noticed, depending on the duration of exposure. The embryos exposed for 10 post-incubation days exhibited decreased retinal growth and mild pigmentation of the epithelium. Growth retardation reallocated to growth enhancement on increasing EMF exposure for 15 post-incubation days, with a shift of pigmentation grade from mild to intense. We conclude that EMF emitted by a mobile phone cause derangement of chicken embryo retinal differentiation."
"It is well established that strong electromagnetic fields (EMFs) can give rise to acute health effects, such as burns, which can be effectively prevented by respecting exposure guidelines and regulations. Current concerns are instead directed toward the possibility that long-term exposure to weak EMF might have detrimental health effects due to some biological mechanism, to date unknown. (1) The possible risk due to pulsed EMF at frequency 2.45 GHz and mean power density 2.8 mW/cm(2) on rat postnatal neurogenesis was studied in relation to the animal's age, duration of the exposure dose, and post-irradiation survival. (2) Proliferating cells marker, BrdU, was used to map age- and dose-related immunohistochemical changes within the rostral migratory stream (RMS) after whole-body exposure of newborn (P7) and senescent (24 months) rats. (3) Two dose-related exposure patterns were performed to clarify the cumulative effect of EMF: short-term exposure dose, 2 days irradiation (4 h/day), versus long-term exposure dose, 3 days irradiation (8 h/day), both followed by acute (24 h) and chronic (1-4 weeks) post-irradiation survival. (4) We found that the EMF induces significant age- and dose-dependent changes in proliferating cell numbers within the RMS. Our results indicate that the concerns about the possible risk of EMF generated in connection with production, transmission, distribution, and the use of electrical equipment and communication sets are justified at least with regard to early postnatal neurogenesis."
"The numbers of granule cells in the dentate gyrus were analyzed using the optical fractionator technique. The results showed that prenatal EMF exposure caused a decrease in the number of granule cells in the dentate gyrus of the rats (P<0.01). This suggests that prenatal exposure to a 900 MHz EMF affects the development of the dentate gyrus granule cells in the rat hippocampus. Cell loss might be caused by an inhibition of granule cell neurogenesis in the dentate gyrus."
"Compared to other groups, adult rats that had been exposed prenatally to the physiologically-patterned magnetic fields at the low (30 - 50 nT) and medium (90 - 580 nT) intensities exhibited peak elevations of aminotransaminase, glucose, and uric acid. Numbers of cytometric anomalies were also significantly elevated within regions of the hippocampus known for neuronal neogenesis in adults. The results suggest that a common factor in cellular adhesion or plasticity might be permanently altered by prenatal exposure to a narrow intensity of a series of physiologically-patterned magnetic fields."
"In the exposed group the weight was significantly decreased only at birth, while the circumferences of the head and chest as well as the height were significantly reduced at all studied ages. The radiological study revealed a significant delay in carpal bone ossification of the exposed children. In conclusion: Exposure to low frequency electromagnetic fields emerged from high voltage electric power lines increases the incidence of growth retardation of children. Isolating these power lines in a scientific way in order to shield both the magnetic and electric fields or removing them far away from the inhabitant areas is recommended."
"These results point out that interactions in developmental toxicology, such as those of RF radiation, 2ME, and methanol that we have studied, are complex, and such interactions cannot be fully understood or predicted without more research. It is important that combined exposure effects be considered when developing both physical agent and chemical agent exposure guidelines and intervention strategies."
"Behavioral, functional, and morphological effects of UWB exposure were unremarkable with these exceptions: (i) The UWB-exposed pups emitted significantly more stress vocalizations than the sham-exposed pups; (ii) the medial-to-lateral length of the hippocampus was significantly longer in the UWB-exposed pups than in the sham-exposed animals; (iii) male offspring exposed in utero to UWB mated significantly less frequently than sham-exposed males, but when they did mate there was no difference in fertilization and offspring numbers from the sham group."
"These results suggest that microwaves (CW, 2 mW/cm(2), 2450 MHz) produce uteroplacental circulatory disturbances and ovarian and placental dysfunction during pregnancy, probably through nonthermal actions. The uteroplacental disturbances appear to be due to actions of PGF(2)alpha and may pose some risk for pregnancy."
"These results, consistent with the literature, add to the evidence that the developmental toxicity of RF radiation (combined or alone) is associated with colonic temperature, not with SAR."
"The results are consistent with previous observations. Dose-related developmental toxicity was observed for 2ME both in the presence and absence of r.f. radiation. However, concurrent RF radiation exposure changed the shape of the dose-effect curve of 2ME. These data indicate that combined exposure effects should be considered when developing exposure guidelines and intervention strategies."
"The results are consistent with previous observations. Significant interactions were observed between 2ME and RF radiation sufficient to maintain colonic temperatures at 41 degrees C for 1 h, but no consistent interactions were seen at lower temperatures even with longer durations. These data indicate that combined exposure effects should be considered when developing both RF radiation and chemical exposure guidelines and intervention strategies."
"Pregnancies of mothers reporting microwave use 6 months prior to the pregnancy or during the first trimester were more likely to result in miscarriage (odds ratio (OR) = 1.28, 95% confidence interval (CI) 1.02-1.59). The odds ratio increased with increasing level of exposure (chi 2 = 7.25, p < 0.005). The odds ratio in the highest exposure group (20 or more exposures/month) was 1.59. The overall odds ratio was slightly lower after it was controlled for prior fetal loss (OR = 1.26, 95% CI 1.00-1.59), but the exposure-response effect remained (chi 2 = 5.17, p < 0.01). The risk of miscarriage was not associated with reported use of shortwave diathermy equipment (OR = 1.07, 95% CI 0.91-1.24). The odds ratio in the highest exposure group was 0.87."
"Microwave radiation for 20 min had an effect that was comparable to that of immersion in 42 degrees C hot water for 15 min. In addition, some animals were examined on day 18 of gestation, and some of their offspring were examined at 6 weeks of age in an examination of long-term effects. Brain weight for the group exposed to microwaves for 20 min was significantly lower than for the control group, and the numerical density of the neurons in the cerebrum was higher. We concluded that microwave radiation at the dose tested mainly has a thermal effect."
"A significant reduction in maternal weight gain, either during treatment on days 1-6 or 6-15 of gestation was observed in females of all handled groups. Handling plus exposure to elevated ambient temperature (30 degrees C or 31 degrees C) during days 6-15 of gestation increased this reduction in maternal weight gain. A significant decrease in implantation sites per litter and reduction in fetal weight was noted in the group exposed to 30 mW/cm2 during days 1-6 of gestation. Exposure of mice to a power density of 30 mW/cm2 (days 6-15 of gestation) resulted in a slight, but significant increase in the percentage of malformed fetuses, predominantly with cleft palate, when compared to all other groups."
In 1971, the U.S. Office of Naval Medical
Research produced a document reporting over 100 different non-thermal effects,
listing 40 apparent neuropsychiatric changes produce by non-thermal microwave
frequency exposures, including 5 central/peripheral nervous system (NS) changes, 9
central NS effects, 4 autonomic system effects, 17 psychological disorders, 4
behavioral changes and 2 misc. effects. It also listed cardiac effects including ECG
changes and cardiac necrosis as well as both hypotension and hypertension, and also 8
different endocrine effects. Changes affecting fertility including tubular degeneration
in the testis, decreased spermatogenesis, alterted sex ratio, altered menstrual activity,
altered fetal development, programmed cell death (what is now known as apoptosis)
and decreased lactation. Many other non-thermal changes where also listed for a total
of over 100 non-thermal effects. They also provided over 1000 citations
documenting these various health effects.
"An experiment has been carried out to determine pathological and longevity effects caused by chronic microwave irradiation of mice. Two hundred males were exposed daily for 59 weeks to 0.100 w/cm2 for 4.5 minutes. This treatment produced an average body temperature rise of 3.3° C. Histopathology was performed on all dead mice in both irradiated and control group. Changes in body weight, in body temperature response to heating, and in the blood picture were not evident. Testicular degeneration in the form of tubule atrophy and neoplasms of the white cells were indicated. Longevity of the mice did not appear to be affected under the prevailing conditions."