The non-ionising radiations from microwaves emitted by telecom base stations and cell phones have been considered safe due to their extremely low power density that does not cause any thermal effect on human cells as long as the exposures are within the limits prescribed by the Inter- national Commission for Non-Ionising Radiation Protection (Icnirp) in its guidelines. Based on studies conducted in the 1990s, Icnrip fixed limits on radiation from cellular base stations that are 4.5 W/m2 for GSM 900, 9.0 W/m2 for GSM 1800 and 10 W/m2 for UMTS (3G) in 1998. Several measurements made of radiation at the base of telecom towers and other locations have found radiation levels much lower than these limits. Therefore, WHO has declared mobile phones and base stations safe for public health.
However, it should be noted that the Icnirp guidelines are based on short-term, immediate health effects such as stimulation of peripheral nerves and muscles and harm caused by tissue temperatures, resulting from absorption of energy during exposure to electromagnetic fields expressed in terms of specific absorption rate (SAR). These are not based on long-term exposure to radiation from cellphone and base stations, particularly from broadband wireless systems such as WiMAX and 3.5G mobile systems.
Subsequent to the publication of the Icnirp guidelines more than a decade back, a number of studies have brought out the dangers of long-term exposure of RF radiation to public health. Notable among these are the Freiburger Appeal published in October 2002 by the interdisciplinary society for environmental medicine of Germany. The Salzburg Resolution of 2000 recommends outdoor exposure limits that are much lower than the Icnirp guidelines, particularly in publicly accessible areas. Similarly, the Catania Resolution recommends preventive strategies based on the precautionary principle. The Paris Charter, signed in March 2003 by three mobile phone operators and the City of Paris, limits public exposure to radiation at levels much lower than the Icnirp limits.
The inadequacies of the existing guidelines have been brought out in the BioInitiative Report 2009 in which a number of adverse biological effects of electromagnetic radiation at very low levels from hundreds of peer-reviewed studies have been highlighted.
It is learnt that in India, the Telecom Commission has decided to adopt Icnirp guidelines. In view of the doubts raised about these guidelines in so many countries, including the European Union, it will be prudent to carefully examine all existing international standards and review the decision already taken. The country will have one billion mobile phones by 2012. To connect so many cell phones, about one million base stations may be required. This will create an enormous electromagnetic smog, particularly in urban areas. The effect of such exposure from multiple base stations has not yet been studied in depth. The latency of a serious disease like cancer is ten to 20 years. Therefore, a precautionary approach is justified.
Some regulatory measures can somewhat mitigate the problem. One is to prescribe the maximum emitted power for various systems in the licence and to measure the same for compliance during acceptance testing. Another could be mandating indoor coverage for all commercial and office buildings, particularly for third generation systems. It is estimated that 80% of the 3G multimedia (data/video) traffic will originate or terminate indoor in crowded urban centers. To provide in-building coverage, outdoor base stations have to increase their power level, ie, radiation contributing to the electromagnetic smog.
In case dedicated indoors cells are provided, their radiation level will come down considerably. Studies have indicated up to 400% increase in system capacity by deployment of indoor pico/ microcells and outdoor macrocells, which will make the environment safer, due to reduction in electromagnetic radiation levels. Last but not the least is to give financial incentive to operators who deploy lower power density systems which are environment-friendly.
Since the 3G systems have a much higher level of radiated power, a number of countries, notably China, have prescribed stricter norms to limit electromagnetic radiation from these systems. These norms are more stringent than what is applicable in Europe/ North America.
Since 3G and broadband wireless access systems like WiMAX are to be inducted in India in the near future, urgent action is required to study the effects of radiation from these systems by an independent group of experts with a view to fixing limits in the Indian context. While various municipal corporations like MCD have recently formulated policies to regulate erection of towers in cities like Delhi, mainly from aesthetic & structural angle, there is no authority at present to regulate radiation from these towers. This must be done by Trai in the interest of public health.
The writer is former member, Trai/Telecom Commission