Electromagnetic radiation is a hot topic in today's society. This paper gives a comprehensive overview of electromagnetic radiation standards at home and abroad. Firstly, it explains the detailed meaning of base station limits and derived limits, and then focuses on the international ICNIRP and IEEE standards. Then, it introduces the use and practice of China's standards. This article will help readers to fully understand the use and revision of electromagnetic radiation standards at home and abroad.
In recent years, with the rapid development of the mobile communication industry and the continuous improvement of people's health awareness, there have been more and more reports on the electromagnetic radiation disputes of base stations in the society, and electromagnetic radiation has gradually become a focus of attention. This article comprehensively elaborates on the standards of electromagnetic radiation at home and abroad.
1. Basic limits and derived limits
Scientific experiments have shown that excessive electromagnetic radiation has a certain harmful effect on the human body. Therefore, many international and national documents currently stipulate human body safety limits for electromagnetic exposure. Although these documents differ in their specific regulations, most documents use the same method: the basic limits and the derived limits are used to give electromagnetic radiation limits.
The basic limit is the basic amount that determines the physiological response of the human body to electromagnetic fields. The basic limits apply to situations in which the body is present. The basic limits of human exposure are usually expressed in terms of Specific Absorp TIon Rate (SAR).
The derived limit is the value that produces the electric field, magnetic field, and power flux density that correspond to the base limit. Since the basic quantities are difficult to measure, most documents give derivation (reference) limits for electric, magnetic and power densities. When the exposure conditions can produce a SAR current density below the basic limit, the derived limit may be exceeded. In other words, if the field strength meets the derived limit, then the base limit must be met. The derived limits apply to situations where the presence of the body does not affect the electromagnetic field.
Exposure limits apply to locations accessible to workers or the general public. Therefore, it is possible to limit the extent to which the entry safety value is exceeded.
It should be pointed out here that when talking about the influence of electromagnetic waves emitted by the base station on the human body, the term "electromagnetic radiation" is usually used in China. In fact, in terms of terms, foreign countries are generally referred to as "electromagnetic exposure" or "electromagnetic exposure." If China also uses the term "electromagnetic exposure" or "electromagnetic exposure", it may reduce the psychological pressure on the public. At present, in the drafting process of relevant standards and national standards, the term "electromagnetic exposure" or "electromagnetic irradiation" has been gradually used.
Internationally, there are two mainstream standards, one is the ICNIRP standard, which is the standard issued by The InternaTIonal Commission for Non-Ionizing Radia TIon ProtecTIon (ICNIRP). The main use scope is in Europe, Australia, Singapore, Brazil. Israel and the Hong Kong Special Administrative Region of our country. But it is worth noting that in Europe, Italy, Luxembourg, Switzerland and Belgium use stricter standards than ICNIRP; Russia nominally uses the standards of the former Soviet Union, which is stricter than the national standard of our country, but because of the base station it uses Most of the equipment comes from Europe, so in fact it also adopts the European system, and its own standards are not carefully implemented. Currently, the Mobile Manufacturers Forum (MMF) is actively promoting activities in China, hoping that China can also adopt the ICNIRP standard.
Another standard is the US IEEE standard. The main use areas are in the United States, Canada, Japan, South Korea, and Taiwan in China (ready to adopt the ICNIRP standard).
ICNIRP standard limits: At 900 MHz, the public derived limit is 450 mW/cm2 ((f(MHz)/200) (W/m2)), and the derived exposure limit for occupational exposure is 2250 mW/cm2 ((f(MHz)/ 40) (W/m2)).
IEEE standard limits: At 900 MHz, the public derived limit is 600 mW/cm2 ((f(MHz)/1500) (W/m2)), and the derived limit for occupational exposure is 3000 mW/cm2 ((f(MHz)/ 300) (W/m2)).
At present, under the impetus of national organizations such as the World Health Organization, the limits of the IEEE standards will be unified to the limits of the European standard (ICNIRP) in the future, and the revision of relevant standards is underway.
Below are some public exposure standards for organizations and countries for reference.
Countries and organizations 900MHz mobile communication band (μw/cm2) 1800MHz mobile communication band (μw/cm2)
China Environmental Protection Agency 40 40
International Commission on Non-Ionizing Radiation 450 900
Hong Kong Telecommunications Authority 450 900
EU 450 900
European Electronic Technical Standards Council 450 900
Japan Post Province Telecommunications Technical Committee 600 1000
Australia 200 200
US FCC 600 1000
US IEEE 600 1000
With regard to electromagnetic radiation standards, China's current situation is that multiple relevant national standards coexist at the same time, and several departments are simultaneously formulating or revising similar national standards. Up to now, the national standards related to electromagnetic radiation in China are as follows:
GB8702-88 "Electromagnetic Radiation Protection Regulations"
GB9715-88 "Environmental Electromagnetic Wave Sanitation Standard"
GB12638-90 "Radiation safety requirements for microwave and ultrashort wave communication equipment"
GB10436-89 "Sanitary Standard for Microwave Radiation in Workplaces"
GB10437-89 "Hybrid Standards for UHF Radiation in Workplaces"
GB16203～96 “Sanitary Standards for Power Frequency Electric Fields in Workplacesâ€
These standards were developed and published by the National Environmental Protection Agency, the Ministry of Health, and the former Ministry of Electrical and Mechanical Services in the late 1980s and early 1990s. At that time, China's mobile communication was just getting started. With the development of society, government departments and the people have new understandings and requirements for health, safety and environmental protection. Coupled with the rapid development of science and technology and the popularization of mobile communications, the current national standard has been exposed. The problem that the standard limits of electromagnetic radiation are inconsistent and the measurement methods are different. This situation cannot meet and adapt to the needs of current social development and the development of the mobile communication industry.
The electromagnetic radiation standard currently used in China is GB8702-88 "Electromagnetic Radiation Protection Regulations", and its public derivation limit between 30MHz and 3GHz is 40mW/cm2. The Ministry of Health also formulated a standard GB9715-88 "Environmental Electromagnetic Hygienic Standards", but the enforcement of the Environmental Protection Agency is generally carried out in accordance with GB8702-88.
In order to adapt to the current social development status and end the current situation of multiple standards coexistence, the National Standards Committee has drafted a "electromagnetic radiation exposure limit and measurement method" in the past few years. In the national standard draft, the public export limit is set at 50mW/cm2. Due to the disputes between the parties, the draft is currently on hold. However, the National Standards Committee has adopted the European standard limit for the electromagnetic radiation of mobile phones (SAR limit is 2.0W/kg).
Due to the inability of the national standard to reach an agreement in the near future, the “Methods for Calculating and Measuring Electromagnetic Radiation of Base Stations in Wireless Communication Systems†(Laboratory Test Methods) and “Methods for Evaluating the Compliance of Electromagnetic Radiation in Use of Base Stations in Wireless Communication Systems†are currently underway within the CCSA. Drafting of the field test method). Since the limit is too sensitive, it is not currently covered.
This article provides a comprehensive description of the current state of electromagnetic radiation standards used internationally and domestically. At present, the reasons for the existence of various electromagnetic radiation standards in the world are very complicated. One of the important reasons is to create technical barriers for the equipment of other countries to enter the domestic market and protect their national industries. In China, the main reason why the new national standard cannot be formulated (revised) for a long time is also due to the interests of various industries and related departments. Due to the different positions, operators and the public have different understandings of the dangers of electromagnetic radiation. These issues are waiting to be gradually resolved in the future.
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