Assessment of Radiofrequency Radiation Emitted From Mobile Phone Base Stations In Khartoum Locality

The Global exposures to emerging wireless technologies from applications including mobile phones, cordless phones, DECT phones, WI-FI, WLAN, Wi MAX, wireless internet, baby monitors, and others may present serious public health consequences. Evidence supporting a public health risk is documented in the BioInitiative Report. New, biologically based public exposure standards for chronic exposure to low-intensity exposures are warranted. Existing safety standards are obsolete because they are based solely on thermal effects from acute exposures. The rapidly expanding development of new wireless technologies and the long latency for the development of such serious diseases as brain cancers means that failure to take immediate action to reduce risks may result in an epidemic of potentially fatal diseases in the future (Sage and David ,2009a). There is widespread public concern about the potential adverse health effects of mobile phones, and especially their associated base-stations. Alongside this there are hundreds of, apparently conflicting, reports in the media about the health effects of mobile phones & base-stations. The scientific literature is large and confusing, also apparently showing very inconsistent effects across studies ( Elaine ,2009). The advent of cellular telephones and other wireless technologies and their wide spread and ever increasing use (see table1 growth of mobile phones in Sudan) has led to increasing public, governmental, and scientific attention to the issue of whether or not adverse effects result from exposure to radiofrequency electromagnetic fields. While there are many natural and man- made sources of radiofrequency fields (RFs) in the environment [Stuchly, 1977; Meltz, 1991], established scientific evidence in support of an adverse human health effect due to RF exposure is largely nonexistent. However, the very fact that there are opportunities for so many human exposures is reason enough to give the matter attention, both in the short term and to at least some extent, into the future. In addition, concern about possible adverse effects due to long duration, low level exposures continues unabated (Martin , 2003). The most serious health endpoints that have been reported to be associated with extremely low frequency (ELF) and/or RF include childhood and adult leukemia, childhood and adult brain tumors, and increased risk of the neurodegenerative diseases, Alzheimer and amyotrophic lateral sclerosis 3 (ALS). In addition, there are reports of increased risk of breast cancer in both men and women, genotoxic effects (DNA damage and micronucleation), pathological leakage of the blood–brain barrier, altered immune function including increased allergic and inflammatory responses, miscarriage and some cardiovascular effects. Insomnia (sleep disruption) is reported in studies of people living in very low-intensity RF environments with WI-FI and cell tower-level exposures (Sage and David ,2009a). The type of EMF emitted by base stations is reported to affect regional cerebral blood flow [Huber et al., 2005], cognitive function [Eliyahu et al., 2006; Hutter et al.,2006], and the autonomic nervous system. In addition, some researchers have speculated about causal connections between EMF from base stations and cancer or neuropsychiatric problems [Moulder et al., 2005;Wilen et al., 2006; Abdel-Rassoul et al., 2007], while others have found no definite evidence of such connections [Regel et al., 2006; Furubayashi, et al ., 2009). Exposure to high-frequency non-ionizing radiation can lead to significant absorption of energy and temperature increases, depending on the radiation intensity. There is increasing evidence that weak high frequency EMF, at intensities well below those necessary to cause any significant heating, can also induce biological effects ( Mann and Roschke, 2004). In many countries, over half the population already uses mobile phones and the market is still growing rapidly. The industry predicts that there will be as many as 1.6 billion mobile phone subscribers worldwide in the year 2005. Because of this, increasing numbers of mobile base stations have had to be installed. Base stations are low-powered radio antennae that communicate with users' handsets(WHO, 2009) . Both ELF and RF radiation induce reactive oxygen species, free radicals that react with cellular molecules including DNA. Free-radical production and/or the failure to repair DNA damage created by such exposures can lead to mutations. Exposures have also been linked to decreased melatonin production, which is a plausible biological mechanism for decreased cancer surveillance in the body, and increased cancer risk . An increased risk of cancers and a decrease in survival has been reported in numerous studies of ELF and RF (Sage and David ,2009a). Existing standard-setting bodies that regulate wireless technologies, assume that there are no bioeffects of concern at exposure levels that do not cause measurable heating. However, it has been established beyond any reasonable 4 doubt that bioeffects and some adverse health effects occur at far lower levels of RF and ELF exposure where no heating (or induced current) occurs; some effects are shown to occur a thousand times or more below the existing public safety limits. New, biologically based public exposure limits are urgently needed. New wireless technologies for cell and cordless phones, other wireless communication and data transmission systems affect living organisms in new ways that our antiquated safety limits have not foreseen, nor protected against (Sage and David ,2009a). Base stations are radio transmitters and receivers that form an essential link in mobile phone communications ,they have antennas mounted either on free standing masts or on existing structures and buildings. The area covered by a base station is called a "cell". Cells usually have a radius of several kilometres and overlap at the edges. More base stations are needed where mobile phone use is high(Breckl and Council,2009) . Base stations are continuously transmitting signals, whereas handset transmits RF energy only while a call is being made. Base stations transmit power levels from a few watts to 100 watts or more, depending on the size of the region or "cell" that they are designed to service. Base station antennae are typically about 20-30 cm in width and a meter in length, mounted on buildings or towers at a height of from 15 to 50 metres above ground. These antennae emit RF beams that are typically very narrow in the vertical direction but quite broad in the horizontal direction. Because of the narrow vertical spread of the beam, the RF field intensity at the ground directly below the antenna is low. The RF field intensity increases slightly as one moves away from the base station and then decreases at greater distances from the antenna. Typically within 2-5 metres of some antennae mounted on rooftops, fences keep people away from places where the RF fields exceed exposure limits. Since antennae direct their power outward, and do not radiate significant amounts of energy from their back surfaces or towards the top or bottom of the antenna, the levels of RF energy inside or to the sides of the building are normally very low (WHO , 2009). Most of the research carried out suggests that exposure to radio waves below levels set out in the guidelines does not cause health problems. however Some evidence does however suggest that changes in brain activity can occur below these levels. As a result, the Independent Expert Group on Mobile Phones 5 (Stewart Group) has recommended a "precautionary approach" be adopted until further research is completed ( Breckl and Council ,2009)