The Adverse Effects of Electromagnetic fields on Reproduction

Transcription

1 The Adverse Effects of Electromagnetic fields on Reproduction Electromagnetic fields (electric and magnetic fields) are produced by the distribution of, and our use of, electricity (low frequency) and mobile telephone and wireless technology (high frequency, radiofrequency or microwaves). There has been increasing concern that electromagnetic fields are not as safe as they were first thought to be. Exposure limits were put in place by the UK government to prevent us getting electric shocks, or being cooked. No acknowledgement by the regulators has been made that adverse health effects are possible from very low levels of exposure. In 1979 however, Wertheimer & Leeper showed an association between very low levels of magnetic fields and an increased risk of developing childhood leukaemia. Since then, most scientists have questioned the limits set by the government as being too high and, increasingly, research is showing that there are significant health effects at low levels of electromagnetic fields (EMFs). For further general information on the health effects of EMFs, see the (free) articles on the Powerwatch website which has articles entitled Powerfrequency EMFs and Health Risks and Radiofrequency EMFs and Health Risks. Both of these summarise the research linking EMF exposure to cancer, dementia, cardiovascular effects (heart attack & strokes), depression & suicide, memory and learning difficulties, behaviour, mood and personality changes, and many more effects. In this article we concentrate on the effects of low and high frequency EMFs on reproduction and summarise some of the research findings below. The research situation changes frequently, so this is just a 'snapshot' in time as at March Where research papers are referred to, the lead author is mentioned and the year the paper was published. Details are included at the end of this article, if you wish to find out more about any of the papers cited. Radiofrequency (microwave) (RF) exposure and reproductive effects Mobile phones or phone-type exposure and male sperm Sperm counts in UK men have fallen by 29% in the last decade. Mobile phones have been used, increasingly, in the last decade and a half. Why should EMFs affect the movement of sperm? One study points to a possible explanation. Lishko (2010) showed that human sperm move to the egg in an electrically created pathway. This may well be affected by external EMFs. Mice, often used as experimental subjects have much larger sperm (relatively speaking) than humans, so they may not be affected as much, and it could explain some of the different laboratory findings. In the annual meeting of the American Society for Reproductive Medicine as early as October 2006, US researchers and doctors in Mumbai, India, reported that the more men used a mobile phone, the worse their sperm count and the poorer the quality of their sperm would be, which was also reported in the research by Agarwal (2008). Using the phone for more than 4 hours a day caused a 25% drop in the number of sperm produced and only 20% of these looked normal. In a study of males attending an infertility clinic in Poland, Wdowiak (2007) found an increase in the percentage of 1

2 sperm cells of abnormal structure and a decrease in sperm movement associated with the duration of exposure to mobile phone radiation. In a study by Mailankot (2009), rats exposed to mobile phones emissions for 1 hour a day for 28 days had impaired semen quality and the authors believed this may affect male fertility adversely. Two studies looking at occupational exposure to RF in the Norwegian navy (Møllerløkken 2008, Baste 2008) showed an increased risk of infertility in men exposed to radiofrequency fields; the higher the exposure, the greater the risk for infertility. Where children were born to exposed men, there were a greater number of girls born than boys, suggesting a hormonal involvement. We cannot recommend that men carry a phone in their front trouser pockets. Fejes (2005), Aitken (2005), Erogul (2006), Yan (2007), Agarwal (2008,2009) and Falzone (2008) concluded that usage of mobile phones, exposure to mobile phone signals, or storage of a mobile phone close to the testes affected sperm counts, movement, viability and structure. In addition to these acute adverse effects of electromagnetic radiation (EMR) on sperm motility, long-term EMR exposure may lead to behavioural or structural changes of the male germ cell. These effects may be observed later in life, and they are to be investigated more seriously. Although we cannot assume that what happens to animals in a laboratory experiment, will also happen to human beings living their normal lives, rat biology is surprisingly similar in many ways to human. If the same thing is true for human beings, it may well be worth while considering taking precautions in case. The graph on the left is taken from a study by C K Chou (from an article in Chinese). It shows clearly that the effect of microwave exposure on sperm persists for a considerable time, not just for the duration of the exposure. De Iuliis (2009) found not only changes in movement and vitality of human spermatozoa exposed to radiofrequency EMFs, but also DNA fragmentation. Changes in DNA may not only affect any children born after such a change, DNA changes can be inheritable, but they may not (Ogawa 2009, Sommer 2009), and the changes may affect future generations in ways that are completely unpredictable. Fructose is an important component in semen that facilitates sperm movement. A significant drop in fructose levels was observed in the group exposed to pulsed radio frequency emitted by a mobile phone kept in the standby position, affecting sperm motility in rabbits (Salama 2009). A previous study (Salama 2008) had shown that standby signals could affect testicular function and structure. 2

3 However, research does not always find evidence of effects. In a study by Ribeiro (2007), rats exposed to GSM phone radiation at just over 1800 MHz showed no changes in testicular function. Radiofrequency exposure and effects on ovaries Gul (2009) found that intrauterine exposure to RF radiation had a toxic effect on rat ovaries, and concluded that the microwaves of mobile phones might decrease the number of follicles in rats by several known and, no doubt, countless unknown mechanisms. A Chinese study (Xu 2009) showed toxic changes to female rats' reproductive organs with exposure to RF radiation. However, the frequency (30 MHz) used experimentally is likely to be from military radar and uncommonly encountered, and at signal levels where an individual, to be exposed, would have to be working nearby, or in the main beam. Radiofrequency exposure and effects during pregnancy Pregnant physiotherapists, who are exposed to microwaves as a result of their occupation, had an increased risk of miscarriage in a study by Ouellet-Hellstrom & Stewart (1993). The microwave levels in the study were not particularly high and are similar to those which will be found in many places near mobile phone base stations and in homes and workplaces with DECT phones or WiFi systems. Some laboratory experiments use creatures further away on the evolutionary ladder from us than rats. This may make the experiments non-comparable to human experience; but the fact that there is a change at all in the biology of living systems may give us pause for thought. De Pomerai found changes in growth rate and maturation in the reproductive stage of nematode worms, when the larvae were exposed to weak microwave fields (2002), and in an experiment on flies, Dr Reba Goodman of Colombia University found that 2 hours mobile phone exposure for 10 days caused significant changes in reproductive genes and cell division (Blank & Goodman 1997). General reproductive effects Trying to identify what may be the cause of the effect on reproductive organs or gestation can be difficult, as it may be more complex than some of the studies allow for which may be one of the reasons why there are conflicting findings. Panagopoulos team (2007) found that when looking at the reproductive capacity of flies, 900 MHz radiation was more bioactive than 1800 MHz. It is interesting that the experiment included only head exposure. It may be that positioning the radiating source nearer to gonads may have had a different effect, explaining some of the conflicting findings in different studies. Powerfrequency exposure and reproductive problems Powerfrequency exposure and male sperm A study by Li (2009) found that men who are exposed to levels of magnetic fields of only 0.16 microtesla (µt) for six or more hours a day were four times as likely to have substandard sperm. Bernabò (2010) found compromised sperm function leading to a 3

4 reduction in fertilization rate when boars were exposed to low frequency electromagnetic fields. Kim (2009) found cell apoptosis (cell death) in mouse testicular germ cells from exposure to 14µT 60 Hz magnetic fields. This is a long way above typical chronic background exposure, but is also considerably below the guidance levels allowed in the UK. Zhang's results (2009) indicate that testicle tissues are damaged by long-term exposure to ELF electromagnetic fields. Miscarriage, foetal damage, and other findings Two surveys carried out in Stoke on Trent, near two different high-voltage powerlines found highly significant links between living near to the powerlines and the incidence of miscarriage. D-K Li (2002) and Lee (2002) found that exposure to EMFs during pregnancy was linked to an increased risk of miscarriage. Lee s study found that the link was especially strong where there were high transient fields, that is, where field levels changed rapidly in a short period of time. This type of exposure can happen in e.g. electric train travel; working near or passing through anti-theft pillars in shops, libraries, etc. Aksen (2006) found changes in the ovary and uterus after exposure to EMFs for over 50 days. Experiments with mice by Hong (2003) and Cao (2006) found that low frequency EMF exposure had some adverse effects on reproduction, including miscarriage, foetal loss and malformation and developmental delay in the offspring. A study by Cech (2007), modelling a woman at 30 weeks pregnancy, demonstrated that foetal exposure could exceed ICNIRP guidelines, when the mother s exposure was below them. They suggested that a revision of reference levels might be necessary. They were not looking at potential specific health outcomes, but it may be that these high levels could shed light on some of the findings of other studies. Summary There is mounting evidence that exposure to electromagnetic fields may influence reproduction, either preconceptional, or during pregnancy. Many exposures are within the control of the individual; you can choose to reduce your use of a mobile phone you can change where you carry a mobile phone you can replace a digital cordless phone with a wired phone, or a low emission phone you can replace a wireless computer connection with a cabled or dlan system you can keep a reasonable distance from working electrical appliances you can check your home and workplace for powerfrequency and radiofrequency emissions and make changes where possible you can check frequently used transport systems (cars, trains, trams, planes) for powerfrequency and radiofrequency emissions and make alternative choices if necessary and possible Some things you may not be able to change, but by taking responsibility for the environment around you, you may be able to make changes that will be sufficient to ensure the healthy delivery of the family you want. 4

5 References Agarwal A et al 2009 Effects of radiofrequency electromagnetic waves (RF-EMW) from cellular phones on human ejaculated semen: an in vitro pilot study Fertil Steril 92(4): Agarwal A et al 2008 Effect of cell phone usage on semen analysis in men attending infertility clinic: an observational study Fertil Steril 89(1):124-8 Aitken RJ et al 2005 Impact of radiofrequency electromagnetic radiation on DNA integrity in the male germline Int J Androl 28(3): Aksen F et al Effect of 50-Hz 1-mT magnetic field on the uterus and ovaries of rats (electron microscopy evaluation) Med Sci Monit 12(6):BR Baste V et al 2008 Radiofrequency electromagnetic fields; male infertility and sex ratio of offspring Eur J Epidemiol 23(5): Bernabò N et al 2010 Extremely low frequency electromagnetic field exposure affects fertilization outcome in swine animal model Theriogenology Feb 20 [Epub ahead of print] Blank M and R Goodman Do electromagnetic fields interact directly with DNA? Bioelectromagnetics 18: Cao YN et al Effects of exposure to extremely low frequency electromagnetic fields on reproduction of female mice and development of offsprings Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 24(8): Cech R et al Fetal exposure to low frequency electric and magnetic fields Phys Med Biol 52(4): De Iuliis GN et al 2009 Mobile phone radiation induces reactive oxygen species production and DNA damage in human spermatozoa in vitro PloS One 4(7):e6446 De Pomerai D et al Growth and maturation of the nemaotode c.elegans following exposure to weak microwave fields, Enzyme and Microbial Technology 30; pp Erogul O et al Effects of electromagnetic radiation from a cellular phone on human sperm motility: an in vitro study Arch Med Research 2006 Oct;37(7): Falzone N et al 2008 In vitro effect of pulsed 900 MHz GSM radiation on mitochondrial membrane potential and motility of human spermatozoa Bioelectromagnetics 29(4): Fejes I et al 2005 Is there a relationship between cell phone use and semen quality? Arch Androl 51(5): Gul A et al 2009 The effects of microwave emitted by cellular phones on ovarian follicles in rats Arch Gynecol Obstet Feb 25 [Epub ahead of print] Hong R et al [Effects of extremely low frequency electromagnetic fields on male reproduction in mice - article in Chinese] Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 21(5): Kim YW et al Effects of 60 Hz 14 microt magnetic field on the apotosis of testicular germ cell in mice Bioelectromagnetics 30(1):66-72 Lee GM et al 2002 A nested case-control study of residential and personal magnetic field measures and miscarriages Epidemiology 13(1):21-31 Li DK et al 2009 Exposure to magnetic fields and the risk of poor sperm quality Reprod Toxicol Oct 13 [Epub ahead of print] Li DK et al 2002 A population-based prospective cohort study of personal exposure to magnetic fields during pregnancy and the risk of miscarriage Epidemiology 13(1):9-20 5

6 Lishko PV et al 2010 Acid Extrusion from Human Spermatozoa is mediated by Flagellar Voltage- Gated Proton Channel Cell 140(3): Mailankot M et al Radio frequency electromagnetic radiation (RF-EMR) from GSM (0.9/1.8GHz) mobile phones induces oxidative stress and reduces sperm motility in rats Clinics (Sao Paulo) 64(6):561-5 Møllerløkken OJ & BE Moen 2008 Is fertility reduced among men exposed to radiofrequency fields in the Norwegian Navy? Bioelectromagnetics 29(5): Panagopoulos DJ et al 2007 Comparison of bioactivity between GSM 900 MHz and DCS 1800 MHz mobile telephony radiation Electromagn Biol Med 26(1):33-44 Ogawa K et al 2009 Effects of gestational exposure to 1.95-GHz W-CDMA signals for IMT-2000 cellular phones: Lack of embryotoxicity and teratogenicity in rats Bioelectromagnetics 30(3): Ouellet-Hellstrom R & W F Stewart Miscarriages among Female Physical Therapists who report using radio- and microwave-frequency electromagnetic radiation AJE 138(10): Ribeiro et al 2007 Effects of subchronic exposure to radio frequency from a conventional cellular telephone on testicular function in adult rats The Journal of Urology 177(1): Salama N et al 2009 The mobile phone decreases fructose but not citrate in rabbit semen: a longitudinal study Syst Biol Reprod Med 55(5-6):181-7 Salama N et al 2008 Effects of exposure to a mobile phone on testicular function and structure in adult rabbit Int J Androl Dec 2 [Epub ahead of print] Sommer AM et al Effects of Radiofrequency Electromagnetic Fields (UMTS) on Reproduction and Development of Mice: A Multi-generation Study, Radiat Res 171(1):89-95 Wdowiak A et al 2007 Evaluation of the effect of using mobile phones on male fertility Ann Agric Environ Med 14(1): Wertheimer N & Leeper E Electrical wiring configurations and childhood cancer Am J Epidemiol 109(3); Xu YQ et al 2009 Female genital toxicities of high-frequency electromagnetic field on rats Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 27(9):544-8 Yan JG et al 2007 Effects of cellular phone emissions on sperm motility in rats Fertil Steril 88(4): Zhang A et al 2009 Study on testicle tissue of rats in extremely low frequency electromagnetic fields Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 26(2):