Sunday, 15 July 2012

Electromagnetic Fields And Public Health@@@


Today, mobile telephony is now commonplace around the world. This wireless technology relies upon an extensive network of fixed antennas, or base stations, relaying information with radiofrequency (RF). Over 1.4 million base stations worldwide, and the number is increasing dramatically with the advent of third generation technologies.

Other wireless networks that allow access and services to high-speed Internet, such as local area networks (WLANs), are also increasingly common in homes, offices and many public places (airports, schools and residential and urban areas). As an increasing number of base stations and local wireless networks increases, so does the population exposure to radio frequencies. Recent studies show that RF exposure from base stations range from 0.002% to 2% of the levels specified in international guidelines on exposure limits, based on a number of factors including the proximity of the antennas and their environment. This is lower or comparable to RF exposures from radio transmitters or TV.

Possible health consequences from exposure to RF fields produced by wireless technologies have caused concern. In this fact sheet reviews the scientific evidence on the effects on human health of exposure to continuous low-level base stations and other local wireless networks. For detailed information on a WHO workshop on this theme.

Health concerns

A common concern about in relation to the antennas of base stations and wireless local networks is related to long-term effects it could have on the health of the whole body exposure to RF energy. To date, the only effect of RF fields on health has been noted in scientific studies related to an increase in body temperature (> 1 ° C) by exposure to a field strength very high that only occurs in certain industrial facilities, such as RF heaters. The levels of RF exposure from base stations and wireless networks are so low that the temperature increases are insignificant and do not affect the health of people.Further info : pearly penile papules on shaft

The strength of RF fields reaches its maximum at the origin and decreases rapidly with distance. Access to places close to the antennas of base stations is restricted where RF signals may exceed international exposure limits. A number of recent studies have shown that RF exposure from base stations and wireless technologies in publicly accessible areas (including schools and hospitals) are normally thousands of times below the limits set by international standards.

In fact, due to their lower frequency, to similar levels of RF exposure, the body absorbs up to five times the signal from the FM radio and television stations base. This is because the frequencies used in FM radio (around 100 MHz) and television (between 300 and 400 MHz) are lower than those employed in mobile telephony (900 and 1800 MHz), since the height people makes the body an efficient receiving antenna. In addition, stations broadcast radio and television work for at least 50 years without experiencing any adverse health effect.

While most radio technologies have used analog signals, modern wireless telecommunications are using digital signals. Detailed reviews conducted so far have not revealed any hazard specific to different RF modulations.

Cancer: the news published by the media on clusters of cases of cancer around base stations mobile phones have alerted the public. It should be noted that from the geographical point of view, cancer is unevenly distributed among any population. Given the widespread presence of base stations in the environment can result in clusters of cancer cases near base stations merely by chance. In addition, cases of cancer reported in these clusters are often of different types with no common characteristics, so it is not likely to have a common cause.

You can obtain evidence on the distribution of cancer cases among the population through epidemiological studies carefully planned and executed. In the past 15 years, have published studies that examined the potential relationship between RF transmitters and cancer. These studies have found no evidence that RF exposure from the transmitters increases the risk of cancer. Similarly, the long-term studies in animals have not established an increased risk of cancer from exposure to RF fields, even at levels much higher than produced by base stations and wireless networks.

Other effects: Few studies on the overall impact on human health from exposure to RF fields from base stations. This is due to the difficulty in distinguishing possible health effects of very low signals emitted by base stations of other RF signals higher strength in the environment. Most studies have focused on the RF exposure from mobile phone users. Studies with humans and animals in which we have examined the brain waves, cognition and behavior after exposure to RF fields, such as those generated by mobile phones, have not identified adverse effects. The RF exposure level used in these studies were about 1000 times higher than the general public exposure to RF from base stations or wireless networks. No evidence of altered sleep or cardiovascular function.

Some individuals have reported nonspecific symptoms following exposure to RF fields from base stations and other EMF devices. As indicated in a recent fact sheet published by the WHO fact sheet "Electromagnetic Hypersensitivity", there is no evidence that electromagnetic fields cause such symptoms. However, it is important to consider the plight of people suffering from these symptoms.

From all evidence accumulated so far, none has shown that the RF signals produced by base stations have adverse short or long term health. Since wireless networks produce generally lower RF signals than base stations, there are expected from exposure to them is injurious to amerihealth mercy insurance.
Protection rules

The International Commission on Non-Ionizing Radiation Protection (ICNIRP, 1998) and the Institute of Electrical and Electronics Engineers (IEEE, 2005) have developed international guidelines on exposure limits to protect against known effects of RF fields.

National authorities should adopt international standards to protect citizens against adverse levels of RF. They should restrict access to areas that may be exceeded exposure limits.

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