Nine new studies on electromagnetic fields and biology or health
Electromagnetic Radiation Safety, June 23, 2016
Time trend in incidence of malignant neoplasms of the central nervous system in relation to mobile phone use among young people in Japan
Sato, Y., Kiyohara, K., Kojimahara, N. and Yamaguchi, N. (2016), Time trend in incidence of malignant neoplasms of the central nervous system in relation to mobile phone use among young people in Japan. Bioelectromagnetics. doi: 10.1002/bem.21982.
The aim of this study was to examine whether incidence of malignant neoplasms of the central nervous system from 1993 to 2010 has increased among young people in Japan, and whether the increase could be explained by increase in mobile phone use. Joinpoint regression analysis of incidence data was performed. Subsequently, the expected incidence rate was calculated assuming that the relative risk was 1.4 for those who used mobile phones more than 1640 h cumulatively. Annual percent change was 3.9% (95% confidence interval [CI], 1.6–6.3) for men in their 20s from 1993 to 2010, 12.3% (95% CI, 3.3–22.1) for women in their 20s from 2002 to 2010, 2.7% (95% CI, 1.3–4.1) for men in their 30s from 1993 to 2010, and 3.0% (95% CI, 1.4–4.7) for women in their 30s from 1993 to 2010. Change in incidence rates from 1993 to 2010 was 0.92 per 100,000 people for men in their 20s, 0.83 for women in their 20s, 0.89 for men in their 30s, and 0.74 for women in their 30s. Change in expected incidence rates from 1993 to 2010 was 0.08 per 100,000 people for men in their 20s, 0.03 for women in their 20s, 0.15 for men in their 30s, and 0.05 for women in their 30s. Patterns in sex-, age-, and period-specific incidence increases are inconsistent with sex-, age-, and period-specific prevalence trends, suggesting the overall incidence increase cannot be explained by heavy mobile phone use.
A compact-sized mobile phone (about 250 g) was first introduced around 1990, followed by the start of digital mobile phone service in 1993. After a major price cut on initial costs and usage fees in 1994, mobile phone use began to spread throughout Japan. The number of mobile phone subscribers in Japan was 8 million in 1996, 54 million in 2000, 90 million in 2005, 115 million in 2010, and 137 million at the end of January 2014, with one or more phones per capita [Telecommunications Carriers Association Japan, 2014].
We extracted data on mobile phone usage from a cohort that we established using a nationwide Internet survey for mobile phone use …. Number of participants in this cohort was 7,550. In the present study, we used sex, date of birth, year starting mobile phone use, average number of calls per day, average duration of one call, and last reply date from this cohort.
In the present study, we assumed that relative risk of malignant neoplasms of the central nervous system was 1.4 for those who used mobile phones more than 1640 h cumulatively.
Annual percent change (APC) during the period from 1993 to 2010 did not show any significant increase or decrease among those aged 10–19 years: 1.6% (95% CI, −0.3 to 3.4) for men and 1.8% (95% CI, −0.4 to 4.0) for women. The APC for men aged 20 to 29 years showed a significant increase during the period from 1993 to 2010: 3.9% (95% CI, 1.6–6.3). For women aged 20 to 29 years, however, APC showed an increasing trend from 1993 to 1997, and a decreasing trend from 1997 to 2002, but neither trend was statistically significant. The APC for this group of women then showed a significant increasing trend from 2002 to 2010: 12.3% (95% CI, 3.3–22.1). The APC for those aged 30 to 39 years showed a statistically significant increase: 2.7% (95% CI, 1.3–4.1) for men, and 3.0% (95% CI, 1.4–4.7) for women. The incidence rate and best-fitting joinpoint regression model are shown in Figure 1. The observed incidence rate per 100,000 people in 1993 was 1.22 for men in their 20s, 0.53 for women in their 20s, 1.76 for men in their 30s, and 1.15 for women in their 30s. The estimated incidence rate per 100,000 people in 1993 was 1.00 for men in their 20s, 0.69 for women in their 20s, 1.55 for men in their 30s, and 1.12 for women in their 30s. The estimated incidence rate per 100,000 people in 2010 was 1.92 for men in their 20s, 1.52 for women in their 20s, 2.44 for men in their 30s, and 1.86 for women in their 30s. The change in incidence rates from 1993 to 2010 was 0.92 per 100,000 people for men in their 20s, 0.83 for women in their 20s, 0.89 for men in their 30s, and 0.74 for women in their 30s.
For men in their 20s, the proportion of heavy users started increasing from 1994, and reached 21.0% in 2010 (n = 75). For women in their 20s, the proportion of heavy users started increasing from 1996, and reached 12.0% in 2010 (n = 97). For men in their 30s, the proportion of heavy users started increasing from 1990, and reached 24.8% in 2010 (n = 234). For women in their 30s, the proportion of heavy users started increasing from 1999, and reached 12.3% in 2010 (n = 275).
The expected incidence rate per 100,000 people with the relative risk of 1.4 in 2010 was 1.08 for men in their 20s, 0.72 for women in their 20s, 1.70 for men in their 30s, and 1.17 for women in their 30s. The change in expected incidence rates with the relative risk of 1.4 from 1993 to 2010 was 0.08 per 100,000 people for men in their 20s, 0.03 for women in their 20s, 0.15 for men in their 30s, and 0.05 for women in their 30s.
In our study, the incidence of malignant neoplasms of the central nervous system for 18 years from 1993 to 2010 was found to have significantly increased in both men and women in their 20s and 30s. On the other hand, the incidence rate did not show any significantly increasing trend in men and women aged 10–19 years. If this increase in incidence was caused by a certain exposure, the effect of exposure on the incidence rate should also have increased in the last 20 years among young people aged 20–39 years, especially in men. In light of an increased risk being reported for mobile phone users with cumulative call time exceeding 1640 h, this study attempted to examine whether the observed increase in the incidence rate of malignant neoplasms of the central nervous system could be explained by an increase in the proportion of heavy mobile phone users.
Proportion of heavy users was found to be consistently higher in men than women (Fig. 2b and c), and so was the incidence of malignant neoplasms of the central nervous system, with the exception of the years 1996–1997 among women who were 20–29 years old (Fig. 1b and c). Proportion of heavy users was found to be higher among men aged 30–39 years as compared to men aged 20–29 years (Fig. 2b and c), and so was the incidence rate (Fig. 1b and c). For women, the proportion of heavy users was higher since 2006 for those aged 30–39 years compared to those aged 20–29 years (Fig. 2b and c), and the incidence rate was higher for those aged 30–39 years compared to those aged 20–29 years, with an exception in 2007 (Fig. 1b and c).
The increase in incidence rate started in 1993 for both men and women in their 20s and 30s. The incidence of malignant neoplasms of the central nervous system precedes heavy mobile phone use with the cumulative call time exceeding 1640 h. This trend was remarkable in women in their 30s. The present study does not take into account the latency period between mobile phone use and the incidence of malignant neoplasms of the central nervous system. If we assume that there is a latency period of 5 years, the incidence of malignant neoplasms of the central nervous system preceded by heavy mobile phone use is more significant.
Three major limitations of this study should be mentioned with regard to the analyzed data. First, national estimates of incidence rate, on which the present study relied, are based on regional cancer registries because a nationwide population-based registration system has yet to be established in Japan.
Second, mobile phone usage was obtained from a cohort that was created on the Internet by sending a survey to schools throughout Japan. Therefore, mobile phone usage in the cohort is considered to differ from that in the general population.
Third, the cumulative call time used in this study was calculated from the average talk time and the use period. Change in talk time over the entire period was not investigated. Cumulative call time in the present study shows a rough trend and does not reflect real usage accurately. This is another drawback of the present study.
The incidence rate of malignant neoplasms of the central nervous system has increased significantly in men and women aged 20–29 years and 30–39 years from 1993 to 2010 in Japan. However, patterns in sex-, age-, and period-specific incidence increases are inconsistent with sex-, age-, and period-specific prevalence trends, suggesting the overall incidence increase cannot be explained by heavy mobile phone use. Further epidemiological research is warranted, especially a study with a more accurate estimate of the cumulative exposure level.
Comprehensive personal RF-EMF exposure map and its potential use in epidemiological studies
Gonzalez-Rubio J, Najera A, Arribas E. Comprehensive personal RF-EMF exposure map and its potential use in epidemiological studies. Environ Res. 2016 May 16;149:105-112. doi: 10.1016/j.envres.2016.05.010. [Epub ahead of print]
In recent years, numerous epidemiological studies, which deal with the potential effects of mobile phone antennas on health, have almost exclusively focused on their distance to mobile phone base stations. Although it is known that this is not the best approach to the problem, this situation occurs due to the numerous difficulties when determining the personal exposure to the radiofrequency electromagnetic fields (RF-EMF). However, due to the rise of personal exposimeters, the evolution of spatial statistics, the development of geographical information systems and the use of powerful software, new alternatives are available to deal with these epidemiological studies and thus overcome the aforementioned difficulties. Using these tools, this paper presents a lattice map of personal RF-EMF exposure from exterior mobile phone base stations, covering the entire 110 administrative regions in the city of Albacete (Spain). For this purpose, we used a personal exposimeter, Satimo EME Spy 140 model, performing measurements every 4s The exposimeter was located inside the plastic basket of a bicycle, whose versatility permitted the access to all the zones of the city. Once the exposure map was prepared, its relation with the known antenna locations was studied. The 64 mobile telephone antennas of the city were also georeferenced; the randomness of both variables (exposure and antennas) were studied by means of the Moran’s I test. Results showed that the distribution of the antennas follows a grouped pattern (p<0.001), while the distribution of the average exposure values have a random distribution (p=0.618). In addition, we showed two Spearman correlation studies: the first between the average exposure values and the number of mobile telephone antennas per administrative region, and the second, also considering the antennas of the neighbouring regions. No substantial correlation was detected in either of the two cases. This study also reveals the weaknesses of the epidemiological studies, which only take into account the distance to the antennas, which would provide a new approach to the problem. By precisely knowing the resident population of each administrative region of the city, this proves to be highly useful to rely on a prepared aggregate data map based on the mean exposure values to RF-EMF in these sections. The displayed map would permit the execution of more accurate epidemiological studies, since it would be possible to compare the exposure measurements with the incidence data of a disease.
Environmental Radiofrequency Electromagnetic Fields Exposure at Home, Mobile and Cordless Phone Use, and Sleep Problems in 7-Year-Old Children
Huss A, van Eijsden M, Guxens M, Beekhuizen J, van Strien R, Kromhout H, Vrijkotte T, Vermeulen R. Environmental Radiofrequency Electromagnetic Fields Exposure at Home, Mobile and Cordless Phone Use, and Sleep Problems in 7-Year-Old Children. PLoS One. 2015 Oct 28;10(10):e0139869. doi: 10.1371/journal.pone.0139869. eCollection 2015.
BACKGROUND: We evaluated if exposure to RF-EMF was associated with reported quality of sleep in 2,361 children, aged 7 years.
METHODS: This study was embedded in the Amsterdam Born Children and their Development (ABCD) birth cohort study. When children were about five years old, school and residential exposure to RF-EMF from base stations was assessed with a geospatial model (NISMap) and from indoor sources (cordless phone/WiFi) using parental self-reports. Parents also reported their children’s use of mobile or cordless phones. When children were seven years old, we evaluated sleep quality as measured with the Child Sleep Habits Questionnaire (CSHQ) filled in by parents. Of eight CSHQ subscales, we evaluated sleep onset delay, sleep duration, night wakenings, parasomnias and daytime sleepiness with logistic or negative binomial regression models, adjusting for child’s age and sex and indicators of socio-economic position of the parents. We evaluated the remaining three subscales (bedtime resistance, sleep anxiety, sleep disordered breathing) as unrelated outcomes (negative control) because these were a priori hypothesised not to be associated with RF-EMF.
RESULTS: Sleep onset delay, night wakenings, parasomnias and daytime sleepiness were not associated with residential exposure to RF-EMF from base stations. Sleep duration scores were associated with RF-EMF levels from base stations. Higher use mobile phones was associated with less favourable sleep duration, night wakenings and parasomnias, and also with bedtime resistance. Cordless phone use was not related to any of the sleeping scores.
CONCLUSION: Given the different results across the evaluated RF-EMF exposure sources and the observed association between mobile phone use and the negative control sleep scale, our study does not support the hypothesis that it is the exposure to RF-EMF that is detrimental to sleep quality in 7-year old children, but potentially other factors that are related to mobile phone usage.
The present study assessed the effect of RF-EMF exposure at age 5 from several sources on sleep problems in children at 7 years of age. Of five evaluated sleep scores, only higher exposure levels from mobile phone base stations (>90th percentile) was associated with less favourable sleep duration and with fewer parasomnias. Exposure to indoor sources was not associated with sleep scores, except absence of the indoor sources, which was associated with one of the control sleep scales, sleep anxiety. Regarding mobile phone and cordless phone use, less favourable sleep onset delay, sleep duration and parasomnias were increased with higher levels of mobile phone use. Mobile phone usage was also associated with one of our control sleep subscales, bedtime resistance. Higher level of cordless phone use was not associated to any of our sleep scales.
In conclusion, the children exposed to higher levels of base station exposure had worse sleep scores of sleep duration but improved sleep scores of parasomnias, but we did not observe a similar effect in children exposed to RF-EMF from indoor sources. Also, we observed more sleeping problems in children that were reported to be higher users of mobile phones. This association was not present in children reported to be higher users of cordless phones. Given the differences of results across the evaluated RF-EMF exposure sources, our study does not provide support for the hypothesis that it is the exposure to environmental RF-EMF that is detrimental to sleep quality in 7-year old children, but rather other factors that are related to mobile phone usage as such. Our observation is in line with previous publications that have reported effects of electronic media use on children’s sleep.
Open Access Paper: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4625083/
Electromagnetic Fields Act Similarly in Plants as in Animals: Probable Activation of Calcium Channels via Their Voltage Sensor
Martin L Pall. Electromagnetic Fields Act Similarly in Plants as in Animals: Probable Activation of Calcium Channels via Their Voltage Sensor. Current Chemical Biology, Volume 10 (E-pub ahead of print)
It has been shown that low intensity microwave/lower frequency electromagnetic fields (EMFs) act in animals via activation of voltage-gated calcium channels (VGCCs) in the plasma membrane, producing excessive intracellular calcium [Ca2+]i , with excessive [Ca2+]i leading to both pathophysiological and also in some cases therapeutic effects. The pathophysiological effects are produced largely through excessive [Ca2+]i signaling including excessive nitric oxide (NO), superoxide, peroxynitrite, free radical formation and consequent oxidative stress. The activation of the VGCCs is thought to be produced via EMF impact on the VGCC voltage sensor, with the physical properties of that voltage sensor predicting that it is extraordinarily sensitive to these EMFs. It is shown here that the action of EMFs in terrestrial, multicellular (embryophyte) plants is probably similar to the action in animals in most but not all respects, with calcium channel activation in the plasma membrane leading to excessive [Ca2+]i , leading in turn to most if not all of the biological effects. A number of studies in plants are briefly reviewed which are consistent with and supportive of such a mechanism. Plant channels most plausibly to be involved, are the so-called two pore channels (TPCs), which have a voltage sensor similar to those found in the animal VGCCs.
The effect of cell-phone radiation on rabbits: Lymphocyte enzyme-activity data
- V. Zakharchenko, A. V. Kovzan, N. V. Khunderyakova, T. V. Yachkula, O. V. Krukova, R. G. Khlebopros, P. M. Shvartsburd, N. I. Fedotcheva, E. G. Litvinova, M. N. Kondrashova. The effect of cell-phone radiation on rabbits: Lymphocyte enzyme-activity data. Biophysics. 61(1):100-104. 2016.Abstract
The effect of a GSM 900/1800 mobile phone, which is a widespread source of electromagnetic radiation of the microwave frequency in the environment, on rabbits was studied at power densities of 5–7 μW/cm2. The biological effect was recorded by a sensitive method for the detection of the physiological regulation of enzyme activity inside lymphocytes in blood smears. Succinate dehydrogenase, which is the most powerful energy-supply enzyme in mitochondria, and lactate dehydrogenase, which is an enzyme of glycolysis, were measured. The lactate dehydrogenase to succinate dehydrogenase activity ratio was also calculated as an analog of the Warburg effect, which demonstrates the relationship between glycolysis and respiration. After 60 min of mobile-phone exposure each day for 11 days at a moderate dose, the emitted radiation induced a threefold increase in succinate dehydrogenase activity and a twofold decrease in lactate dehydrogenase activity. As a result, the lactate dehydrogenase/succinate dehydrogenase activity ratio falls from 15 to 5, thus indicating that respiration is predominant over glycolysis. The changes develop already after the first exposure and reach a maximum in 4 days. The predominance of respiration is usually considered as a beneficial state of an organism. However, continuous activation of respiration by mobile phone exposure may cause damage to the normal restorative processes that are supported by glycolysis during periods of rest.
Weak electromagnetic fields alter Ca2+ handling and protect against hypoxia-mediated damage in primary newborn rat myotube cultures
Adler D, Fixler D, Scheinowitz M, Shainberg A, Katz A. Weak electromagnetic fields alter Ca2+ handling and protect against hypoxia-mediated damage in primary newborn rat myotube cultures. Pflugers Arch. 2016 May 18. [Epub ahead of print]
Weak electromagnetic fields (WEF) enhance Ca2+ entry into cells via voltage-gated Ca2+ channels and affect various aspects of metabolism, structure, and function. However, little information is available on the effect of WEF on skeletal muscle, which depends primarily on intracellular Ca2+ stores for function and metabolism. Here, we examine the effects of 30 min exposure of rat primary myotube cultures to WEF (1.75 μT, 16 Hz) on Ca2+ handling and creatine kinase (CK) release. Free myoplasmic Ca2+ concentration ([Ca2+ i]) was measured with the ratiometric dye indo-1. WEF did not affect basal [Ca2+]i but decreased the twitch [Ca2+]i transient in a time-dependent manner, and the twitch amplitude was decreased to ∼30 % after 30 min. WEF completely abolished the increase in [Ca2+]i induced by potassium chloride (∼60 mM) but had no effect on the increase induced by caffeine (∼6 mM). Hypoxia (2 h exposure to 100 % argon) resulted in a marked loss of CK into the medium (400 % of normoxic value), as well as a rapid (within 20 min) and sustained increase in basal [Ca2+]i (∼20 % above baseline). However, during exposure to WEF, basal [Ca2+]i remained constant during the initial 60 min of hypoxia and, thereafter, increased to levels similar to those observed in the absence of WEF. Finally, WEF blocked about 80 % of hypoxia-mediated CK release (P < 0.05). These data demonstrate that WEF inhibits increases in [Ca2+]i by interfering with muscle excitation and protects against muscle damage induced by hypoxia. Thus, WEF may have therapeutic/protective effects on skeletal muscle.
On a Possible Mechanism of the Effect of Microwave Radiation on Biological Macromolecules
Nikiforov VN, Ivanov AV, Ivanova EK, Tamarov KP, Oksengendler BL. [On a Possible Mechanism of the Effect of Microwave Radiation on Biological Macromolecules]. Biofizika. 2016 Mar-Apr;61(2):255-8. [Article in Russian]
A model describing the process of dissociation of hydrogen bonding in water clusters when irradiated by electromagnetic field in the microwave range is suggested. The model is also applicable for the case of rupture of the covalent bond of the water molecule cluster. If the energy absorption occurs at the interface of water and polymer clusters (e.g., DNA, chitosan), degradation of the polymer chain is possible.
Memory loss risk assessment for the students nearby high-voltage power lines-a case study
Ghadamgahi M, Monazzam MR, Hosseini M. Memory loss risk assessment for the students nearby high-voltage power lines-a case study. Environ Monit Assess. 2016 Jun;188(6):355. doi: 10.1007/s10661-016-5358-4. Epub 2016 May 18.
With increasing sources of alternating current electromagnetic fields (EMFs) in everyday life, their possible harmful effects on human health are a main area of concern in many countries. Given that children are the most valuable assets of each country, it is of utmost importance to study the effect(s) of EMF exposure on various health aspects of members within this age group. The present research is the first systematic study of the effects of exposure to electric substations on the memory status of male students in the age group of 10 to 12 years. The flux density values of extremely low frequency magnetic field were measured at four elementary schools in Tehran in accordance with IEEE std 644-1994. The device was 3-axis (X, Y, and Z) Gauss Meter, model: TES-1394. The students from two schools nearby a high voltage electricity substation (at distances of 30 and 50 m) were selected as the exposed group, and the students of two other schools at further distances of 1390 and 610 m were considered as the control group. To determine the status of working memory in the students, the questionnaire was adapted from Wechsler Intelligence Scale for Children (WISC-IV). The completed questionnaires were analyzed by t test and chi-square using SPSS 20. The average magnetic flux density was 0.245 μT at case schools and 0.164 μT at control schools, P < 0.01. The demographic characteristics of the students in the two groups were not statistically different. However, the difference in working memory was significant at the level of 5 %. The results of the questionnaire data showed that students in the control group had better working memory compared to students in case group. The findings revealed a reverse correlation between magnetic flux density and working memory of students (R = -0.255). It is concluded that extremely low frequency magnetic field exposure may have a negative impact on the working memory of children, but further studies are necessary to reach a definitive conclusion.
Association between Exposure to Smartphones and Ocular Health in Adolescents
Kim J, Hwang Y, Kang S, Kim M, Kim TS, Kim J, Seo J, Ahn H, Yoon S, Yun JP, Lee YL, Ham H, Yu HG, Park SK. Association between Exposure to Smartphones and Ocular Health in Adolescents. Ophthalmic Epidemiol. 2016 Jun 2:1-8. [Epub ahead of print]
PURPOSE: Smartphone use has dramatically increased in recent years. Smartphones may have adverse health effects, particularly on the eyes, because users stare at the screen for a much longer time than they do with ordinary mobile phones. The objective of this study was to elucidate the relationship between smartphone use and ocular symptoms among adolescents.
METHODS: Information on smartphone use and ocular symptoms (blurring, redness, visual disturbance, secretion, inflammation, lacrimation and dryness) related to eye fatigue and strain from 715 adolescent subjects from three cities in Korea was obtained using a structured questionnaire. Ocular health was scored using number of ocular symptoms. Odds ratios (ORs), 95% confidence intervals (95% CIs) and p-values for ocular symptoms were calculated with binomial and multinomial logistic regression models.
RESULTS: Higher prevalence rates for ocular symptoms were observed in groups with greater exposure to smartphones (p < 0.05). Longer daily smartphone use was associated with a higher likelihood of having multiple ocular symptoms (5-7 symptoms out of 7 symptoms; p = 0.005). Excessive/intermittent use (>2 hours daily and ≤2 hours continuously) and excessive/persistent use (>2 hours daily and >2 hours continuously) compared to shorter use (<2 hours daily) were associated with multiple ocular symptoms (OR 2.18, 95% CI 1.09-4.39; OR 2.26, 95% CI 1.11-4.57, respectively). A higher lifetime exposure to smartphones was associated with a higher likelihood of having multiple ocular symptoms (OR 3.05, 95% CI 1.51-6.19; p = 0.001).
CONCLUSION: Increasing exposure to smartphones can have a negative impact on ocular health in adolescents.
Joel M. Moskowitz, Ph.D., Director
Center for Family and Community Health
School of Public Health
University of California, Berkeley
Electromagnetic Radiation Safety