EVALUATING SHORT-TERM EXPOSURE TO WI-FI SIGNALS ON STUDENTS' REACTION TIME, SHORT-TERM MEMORY AND REASONING ABILITY.

This study investigated the effect of short-term exposure to Wi-Fi signals on the cognitive functions of the mind. After obtaining permission from the local Ethics Committee of Shiraz University of Medical Sciences and approval by the Iranian Registry of Clinical Trials (IRCT2017041233398N1), 45 male and female students from Shiraz University of Medical Sciences volunteered to participate in this study. They were exposed to Wi-Fi signals in two sham and exposure sessions, each for 2 hours. After completion, they took part in reaction time, short-term memory, and reasoning ability tests. After scoring, the data were analysed by SPSS software. In addition, the electric field strength and power density were calculated. The results showed no statistically significant differences between the mean scores of reaction time, short-term memory, and reasoning ability in sham and exposure. Also, the obtained values from the electric field strength and power density (E = 4.1 Vm-1, P = 0.446 Wm-2) were lower than that of threshold values by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Our results can greatly reduce concerns regarding the effects of short-term exposure to Wi-Fi waves on cognitive functions.

Electromagnetic Fields of Mobile Phone Jammer Exposure on Blood Factors in Rats.

BACKGROUND: The increasing demand for using mobile phones has led to increasing mobile phone jammers as well. On the other hand, reports show that exposure to electromagnetic field causes an increase in the incidence of diseases such as leukemia, cancer, depression and failure in pregnancy outcomes; therefore, the aim of this study is to investigate the effects of exposure to electromagnetic fields of mobile phone jammers on blood factors. MATERIALS AND METHODS: Thirty male Wistar immature and thirty mature rats were selected randomly and each one was divided into three groups of ten. The control group did not receive any radiation; the sham group was exposed to a switched-off jammer device and the experimental group was exposed to electromagnetic fields (EMF) radiated by Mobile Phone Jammer daily eight hours for five days a week during forty days. Blood sample was taken from heart and blood factors including PLT, MCHC and RDWCV were measured. The data were analyzed by ANOVA which was followed by Duncan's test. RESULTS: The data from mature rats revealed that jammer usage led to a significant difference in blood factors including RBC, platelet, hemoglobin, hematocrit, MCV and RDWCV (P≤0.05); however, the number of lymphocytes, WBC and MCVH in the blood was the same in all groups. In immature rats, the exposure to jammer did not change RBC, lymphocyte and WBC count, hemoglobin and hematocrit; while, the platelet count along with MCHC, MVC and RDWCV changed by jammer radiation. CONCLUSION: The results exhibited that mobile phone jammer caused frequent changes in blood cell factors.

Short-Term Exposure to Electromagnetic Fields Generated by Mobile Phone Jammers Decreases the Fasting Blood Sugar in Adult Male Rats.

BACKGROUND: Substantial evidence indicates that exposure to electromagnetic fields (EMF) above certain levels can affect human health through triggering some biological responses. According to WHO, short-term exposure to EMF at the levels present in the home/environment do not cause any apparent detrimental effects in healthy individuals. However, now, there is a debate on whether long-term exposure to low level EMF can evoke detrimental biological responses. Although based on the Communications Act of 1934, selling, advertising, using, or importing mobile jammers which block cell phone calls and text messages are illegal acts, in some countries these devices are being used for security purpose and for prevention of cheating during examinations. METHODS: In this study 30 male Wistar rats were randomly divided into 3 groups of 10 each. The control group received no radiation. The sham exposure group was exposed to a switched-off jammer device. After fasting for 12 hours, the exposure group was exposed to EMFs at a distance of 50 cm from the jammer. Blood samples were collected from the tail vein after 24, 48 and72 hours and fasting blood sugar was measured by using a common blood glucose monitor (BIONIME GM110, Taiwan). The significance level was considered 5% and SPSS Ver. 21 was used for statistical analysis. The data were analyzed by ANOVA followed by Tukey's test. RESULTS: A statistically significant difference was observed between blood sugar level in the control and exposure groups after 24, 48 and 72 hours of continuous irradiation (p values were <0.001, <0.001 and 0.002, respectively). No significant difference was found between the level of fasting blood sugar in control and sham groups. CONCLUSION: Short-term exposure to electromagnetic field generated by mobile phone jammer can reduce blood sugar level in adult male rats. These findings, in contrast with our previous results, lead us to this conclusion that the use of these signal blocking devices in very specific circumstances may have some therapeutic effects. However, further studies have to be performed to find out the exact mechanism by which Jammer EMFs reduce fasting blood sugar.

A Challenging Issue in the Etiology of Speech Problems: The Effect of Maternal Exposure to Electromagnetic Fields on Speech Problems in the Offspring.

BACKGROUND: Nowadays, mothers are continuously exposed to different sources of electromagnetic fields before and even during pregnancy.  It has recently been shown that exposure to mobile phone radiation during pregnancy may lead to adverse effects on the brain development in offspring and cause hyperactivity. Researchers have shown that behavioral problems in laboratory animals which have a similar appearance to ADHD are caused by intrauterine exposure to mobile phones. OBJECTIVE: The purpose of this study was to investigate whether the maternal exposure to different sources of electromagnetic fields affect on the rate and severity of speech problems in their offspring. METHODS: In this study, mothers of 35 healthy 3-5 year old children (control group) and 77 children and diagnosed with speech problems who had been referred to a speech treatment center in Shiraz, Iran were interviewed. These mothers were asked whether they had exposure to different sources of electromagnetic fields such as mobile phones, mobile base stations, Wi-Fi, cordless phones, laptops and power lines. RESULTS: 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). However, other exposures had no effect on the occurrence of speech problems. To the best of our knowledge, this is the first study to investigate a possible association between maternal exposure to electromagnetic field and speech problems in the offspring. Although a major limitation in our study is the relatively small sample size, this study indicates that the maternal exposure to common sources of electromagnetic fields such as mobile phones can affect the occurrence of speech problems in the offspring.

Does Occupational Exposure of Shahid Dastghieb International Airport Workers to Radiofrequency Radiation Affect Their Short Term Memory and Reaction Time?

BACKGROUND: Airport workers are continuously exposed to different levels of radiofrequency microwave (RF/MW) radiation emitted by radar equipments. Radars are extensively used in military and aviation industries. Over the past several years, our lab has focused on the health effects of exposure to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons and MRI. The main goal of this study was to investigate if occupational exposure of Shahid Dastghieb international airport workers to radiofrequency radiation affects their short term memory and reaction time. METHODS: Thirty two airport workers involved in duties at control and approach tower (21 males and 11 females), with the age range of 27-67 years old (mean age of 37.38), participated voluntary in this study. On the other hand, 29 workers (13 males, and 16 females) whose offices were in the city with no exposure history to radar systems were also participated in this study as the control group. The employees' reaction time and short term memory were analyzed using a standard visual reaction time (VRT) test software and the modified Wechsler memory scale test, respectively. RESULTS: The mean± SD values for the reaction times of the airport employees (N=32) and the control group (N=29) were 0.45±0.12 sec and 0.46±0.17 sec, respectively.  Moreover, in the four subset tests; i.e. paired words, forward digit span, backward digit span and word recognition, the following points were obtained for the airport employees and the control group, respectively: (i) pair words test: 28.00±13.13 and 32.07±11.65, (ii) forward digit span: 8.38±1.40 and 9.03±1.32, (iii) backward digit span: 5.54±1.87 and 6.31±1.46, and (iv) word recognition: 5.73±2.36 and 6.50±1.93. These differences were not statistically significant. CONCLUSION: The occupational exposure of the employees to the RF radiation in Shahid Dastghieb international airport does not have any significant detrimental effect on their reaction time as well as short term memory.