Mobile phones and their towers produce RF signals/Electromagnetic Fields (EMF); emissions within internationally laid down exposure limits to be protective of our health and wellbeing.

From a technology infrastructure point of view, for a mobile phone to work and communicate well:

• A network of base stations to connect customers' calls and deliver the data they need;
• Use Radio frequency (RF) fields to send and receive calls, texts, emails, pictures, web, TV and downloads; an RF signal is sent to the nearest base station (often called a mobile tower), which sends the signal to a digital exchange and on to the main telephone network or on to the internet. This connects the signal to the receiving phone, again via a base station (if it is another mobile phone) or a fixed line phone or the internet;
• Use the minimum transmit power needed to communicate with the base station. This automatically adjusts according to the signal at the base station. The better the signal – the lower the transmitted power needed from the mobile phone. The power needed depends on a range of factors, including:
  • Distance between the mobile phone and the base station;
  • Landscape and buildings between the mobile phone and the base station;
  • Operating frequency band at a given time; and
  • The service the mobile phone is being used for (e.g. texting, data or voice calls)
• Connects to the base station providing the best signal – usually the nearest one. As a person moves away from the base station the signal becomes weaker, so the mobile phone automatically adjusts its own transmit power to maintain the minimum needed to communicate with the base station.

The area covered by a base station is known as a "cell". Each cell is usually split into three sectors, which overlap with the sectors of neighbouring cells to create a seamless and uninterrupted mobile network. When people travel, the signal is passed from one base station to the next, and typically never has to travel further than the nearest base station.

The size and shape of each cell is determined by the features of the surrounding area, such as buildings, trees and hills, which can block signals.

• Cells are largest in flat open landscapes, where they can cover a radius of several kilometres.
• Cells in urban areas typically range between 200-500mts radius.
• The smallest cells, covering a radius of a few tens or hundreds of metres, are in built-up dense urban areas, where micro-cell base stations are used to provide extra coverage and capacity.
• Each base station can only handle a limited number of connections at a time.
• In areas of high demand, additional antennas are sometimes added to a base station to send and receive more calls and other mobile services, or an extra base station is installed.
• A large number of base stations are needed to allow more people to use mobile phones, from more locations, and for coverage to be continuous when moving around.

Mobile phones and their towers produce RF signals/Electromagnetic Fields (EMF); emissions within internationally laid down exposure limits to be protective of our health and wellbeing.

From a technology infrastructure point of view, for a mobile phone to work and communicate well:

• A network of base stations to connect customers' calls and deliver the data they need;
• Use Radio frequency (RF) fields to send and receive calls, texts, emails, pictures, web, TV and downloads; an RF signal is sent to the nearest base station (often called a mobile tower), which sends the signal to a digital exchange and on to the main telephone network or on to the internet. This connects the signal to the receiving phone, again via a base station (if it is another mobile phone) or a fixed line phone or the internet;
• Use the minimum transmit power needed to communicate with the base station. This automatically adjusts according to the signal at the base station. The better the signal – the lower the transmitted power needed from the mobile phone. The power needed depends on a range of factors, including:
  • Distance between the mobile phone and the base station;
  • Landscape and buildings between the mobile phone and the base station;
  • Operating frequency band at a given time; and
  • The service the mobile phone is being used for (e.g. texting, data or voice calls)
• Connects to the base station providing the best signal – usually the nearest one. As a person moves away from the base station the signal becomes weaker, so the mobile phone automatically adjusts its own transmit power to maintain the minimum needed to communicate with the base station.

The area covered by a base station is known as a "cell". Each cell is usually split into three sectors, which overlap with the sectors of neighbouring cells to create a seamless and uninterrupted mobile network. When people travel, the signal is passed from one base station to the next, and typically never has to travel further than the nearest base station.

The size and shape of each cell is determined by the features of the surrounding area, such as buildings, trees and hills, which can block signals.

• Cells are largest in flat open landscapes, where they can cover a radius of several kilometres.
• Cells in urban areas typically range between 200-500mts radius.
• The smallest cells, covering a radius of a few tens or hundreds of metres, are in built-up dense urban areas, where micro-cell base stations are used to provide extra coverage and capacity.
• Each base station can only handle a limited number of connections at a time.
• In areas of high demand, additional antennas are sometimes added to a base station to send and receive more calls and other mobile services, or an extra base station is installed.
• A large number of base stations are needed to allow more people to use mobile phones, from more locations, and for coverage to be continuous when moving around.

Radio waves – or radio frequency (RF) fields or EMF are created both by mobile phones as well as base stations. International bodies such as the International Commission for Non-Ionizing Radiation Protection (ICNIRP) have laid down guidelines for exposure limits for both mobile phones as well as base stations; ICNIRP is a non-Government body that is formally recognized by the World Health Organization.

The exposure limits for EMF fields developed by ICNIRP were developed following extensive reviews of peer- reviewed scientific literature, including thermal and non-thermal effects. The guidelines are based on evaluations of biological effects that have been established to have health consequences.

Exposure within the ICNIRP limits is not known to cause any harm to our health and these are designed to protect the whole population, including children.

WHO has stated that "Strict adherence to existing national or international safety standards: such standards, based on current knowledge, are developed to protect everyone in the population with a large safety factor."

Exposure to radio frequency (RF) fields from mobile phones is measured and reported as the specific absorption rate (SAR) i.e., the amount of energy from an RF field absorbed by the human body, expressed in watts per kilogram (W/kg).

SAR is the accepted international measure of exposure to electromagnetic fields from mobile phones. When you buy a mobile phone, the SAR value as determined under standardised test conditions must be provided in the product safety information. Many manufacturers also make this information available on their own website or the Mobile Manufacturers Forum website.

While SAR values are an important tool in judging the maximum exposure to RF energy from a particular model of mobile phone, a single SAR value does not provide information about the amount of RF exposure under typical usage conditions. Thus actual exposure from individual mobile phone models under typical use conditions is difficult to determine and may be different on different networks or for different people.

The level of exposure depends on the distance between the person and the mobile and the amount of RF power the mobile phone transmits. Mobile phones always use the minimum amount of energy to provide a service, so actual exposure varies continually depending on a range of factors:

• The distance between the person and the mobile device
  RF field exposure is much reduced with even a short separation distance from a mobile. Keeping the mobile away from the body by using an earpiece or the loudspeaker function will significantly reduce exposure.
• The distance from the base station
  The signal from a base station becomes weaker the further away the mobile is, meaning the RF field strength from the mobile must increase so it can still communicate with the base station. Using the phone in areas of good reception decreases exposure as it allows the phone to transmit at reduced power.
• The landscape between the user and the base station
  If there is a building, hill or other obstruction between the mobile and the base station, the signal from the base station may also be weaker.
• The service being used
  Making a voice call from a mobile leads to greater exposure to RF fields than texts, emails, picture messaging, web, TV and downloads. This is because voice calls are generally made with the mobile next to the head, while it is held away from the body when sending texts and emails and watching TV. Calls also take longer than sending texts and emails, again increasing exposure.

At Vi™, we support the advice from the World Health Organization (WHO). WHO in its Fact Sheet 193 on Electromagnetic fields and public health: mobile phones states that: "To date, no adverse health effects have been established as being caused by mobile phone use".

For those who are still concerned, it may be noted that WHO has stated that RF exposure can be reduced through:

• Use of "hands-free" phones, which keep mobile phones away from your head and body during phone calls
• Limiting the number and length of calls you make
• Use your phone in areas of good reception as it allows the phone to transmit at reduced power

While there have been attempts to design mobile covers or radiation shields that absorb RF fields to reduce the person's exposure, the effectiveness of such covers or shields is unproven. They are also likely to affect the quality of service and may in fact increase the mobile's operating power. WHO has also stated that the use of commercial phones for reducing radiofrequency field exposure has not been shown to be effective.

The ICNIRP guidelines recommend a maximum SAR value of 2.0 W/kg averaged over 10g of tissue for a mobile. All mobiles operating below this level are considered safe to use.

In India, the Government requires all new models of mobile phones to comply with SAR values of 1.6 W/kg averaged over 1g of tissue with effect from 1 September 2012 and from 1September 2013, only mobile handsets with SAR values below 1.6 W/kg would be permitted to be manufactured in, or imported in to, India. All mobile handset manufacturers, are required to provide a self-declaration for conformity in respect of SAR values.

ICNIRP has also recommended guidelines for RF exposure from base stations. These guidelines have a substantial safety margin built into them for the protection of the public.

As the number of base stations and local wireless networks increases, so does the RF exposure of the population. WHO has noted in its fact sheet on base stations and wireless technologies that "Recent surveys have shown that the RF exposures from base stations range from 0.002% to 2% of the levels of international exposure guidelines, depending on a variety of factors such as the proximity to the antenna and the surrounding environment. This is lower or comparable to RF exposures from radio or television broadcast transmitters."

A common concern about base station relates to the possible long-term health effects that whole-body exposure to the RF signals may have. As per the WHO, to date, the only health effect from RF fields identified in scientific reviews has been related to an increase in body temperature (> 1 °C) from exposure at very high field intensity found only in certain industrial or professional applications, 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 human health.

The World Health Organisation's (WHO) fact sheet on base stations and wireless technologies discusses the scientific evidence for adverse health effects. It concludes that “there is no convincing scientific evidence that the weak RF (radio frequency) signals from base stations and wireless networks cause adverse health effects”.

WHO has also addressed concerns with regard to media or anecdotal reports of cancer clusters around mobile phone base stations that have heightened public concern. WHO has stated that "It should be noted that geographically, cancers are unevenly distributed among any population. Given the widespread presence of base stations in the environment, it is expected that possible cancer clusters will occur near base stations merely by chance. Moreover, the reported cancers in these clusters are often a collection of different types of cancer with no common characteristics and hence unlikely to have a common cause." WHO goes on to state that "Scientific evidence on the distribution of cancer in the population can be obtained through carefully planned and executed epidemiological studies. Over the past 15 years, studies examining a potential relationship between RF transmitters and cancer have been published. These studies have not provided evidence that RF exposure from the transmitters increases the risk of cancer. Likewise, long-term animal studies have not established an increased risk of cancer from exposure to RF fields, even at levels that are much higher than produced by base stations and wireless networks."

It is pertinent to note that the WHO's research agenda does not include further studies into the effects of RF exposure from base stations. WHO in its above fact sheet has stated "While no health effects are expected from exposure to RF fields from base stations and wireless networks, research is still being promoted by WHO to determine whether there are any health consequences from the higher RF exposures from mobile phones".

In India, the government has, with effect from 1st September 2012, adopted exposure limits which are one-tenth the ICNIRP guidelines making the Indian EMF exposure limits amongst the lowest in the world. As the ICNIRP limits already included a 50 times reduction/safety factor, the lowering of the EMF limits for Base Stations to one-tenth of ICNIRP has added a further margin of safety.

Vodafone India Compliance

Vodafone India has recently certified by 31 March 2013 that all base stations operated by Vodafone in India comply to a limit ten times lower that the ICNIRP guidelines as per Government of India’s notification of revised EMF exposure norms.

There have been thousands of scientific studies into the effects of radio frequency (RF) fields on health. Scientists know more about this than they do about most chemicals.

• Scientists and public health authorities assess risks to human health based on the entire body of evidence, rather than individual scientific studies. The evidence is considered by panels of experts in this field. We look to such expert reviews for advice on mobile phones, towers and health. Read more about expert reviews.
• Public health authorities, including the World Health Organization (WHO), state that there is no convincing evidence that exposure to RF fields from mobile phones and base stations operated within guideline limits has any adverse health effects. Read advice from the WHO on mobile phones and base stations and find further information on the WHO's EMF website.
• However, there are still some gaps in scientific knowledge. We look to the WHO to identify and prioritise research needs and are dedicated to supporting independent scientific research into these areas. Read more about current research programmes.

The World Health Organization (WHO) has published a number of factsheets providing information and guidance on electromagnetic fields (EMF) and public health.

WHO fact sheet N°296 dated December 2005 on Electromagnetic fields and public health - Electromagnetic hypersensitivity (EHS):

“EHS is characterized by a variety of non-specific symptoms, which afflicted individuals attribute to exposure to EMF. The symptoms most commonly experienced include dermatological symptoms (redness, tingling, and burning sensations) as well as neurasthenic and vegetative symptoms (fatigue, tiredness, concentration difficulties, dizziness, nausea, heart palpitation, and digestive disturbances). The collection of symptoms is not part of any recognized syndrome.

…The symptoms are certainly real and can vary widely in their severity. Whatever its cause, EHS can be a disabling problem for the affected individual. EHS has no clear diagnostic criteria and there is no scientific basis to link EHS symptoms to EMF exposure"

WHO fact sheet N°304 dated May 2006 on Electromagnetic fields and public health - Base stations and wireless technologies:

"Considering the very low exposure levels and research results collected to date, there is no convincing scientific evidence that the weak RF signals from base stations and wireless networks cause adverse health effects."

WHO fact sheet N°193 dated June 2011 on Electromagnetic fields and public health: mobile phones:

"To date, no adverse health effects have been established as being caused by mobile phone use."

Electromagnetic fields

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