ENVIRONMENTAL SUSTAINABILITY

ENVIRONMENTAL SUSTAINABILITY

Electromagnetic wave

Electromagnetic wave
  1. Electromagnetic wave is synchronized oscillations of electric and magnetic fields that propagate at the speed of light.
  2. Electromagnetic wave of visible or lower frequencies (i.e., visible light, infrared, microwaves, and radio waves) is called non-ionizing radiation, because its photons do not individually have enough energy to ionize atoms or molecules. The effects of these radiations on chemical systems and living tissue are caused primarily by heating effects from the combined energy transfer of many photons. Electromagnetic waves from common household appliances and cellular phones are examples of non-ionizing radiation. In contrast, high ultraviolet, X-rays and gamma rays are called ionizing radiation since individual photons of such high frequency have enough energy to ionize molecules or break chemical bonds. These radiations have the ability to cause chemical reactions and damage living cells beyond that resulting from simple heating, and can be a health hazard. Essentially, unlike the hazardous ionizing radiation from nuclear waste and atomic energy, electromagnetic waves from cellular phones and base stations do not pose any dangerous health hazardous radiation.
  1. Base station electromagnetic waves do not release free radiated waves ( reference Q1 what is electromagnetic wave ? ), so it has no hazardous effects on human health. For example, the electromagnetic waves in radio stations and wireless television stations are all non-ionizing radiation and do not pose any danger on human health.
  2. Base station power is tremendously attenuated by the air and surrounding buildings. It has very little power that directly contacts with the human body. For example, the transmit power of a base station is often less than the power of wireless ADSL due to air consumption and building blockage into households. So sometimes we cannot get signals at home when using the cell phone, but still can access wireless Internet through ADSL. However, the safety standard “SAR”, recommended by the Taiwan's International Commission, following the standard by Non-Radiation Protection and the World Health Organization, should not exceed 2.0 W / Kg. (SAR is based on how much the human body absorbs electromagnetic waves, and the unit is how many watts per kg.)
  3. The mobile phone usually directly touches our hands, our faces, our ears, and our skin. The electromagnetic wave of the mobile phone has direct contact with the human body. The mobile phone is much closer to the human body than the base station. However, the frequency of the mobile phone is also a non-ionizing radiation wave and thus has no impact on human health. The current general measured value of mobile phones SAR, depending on brand and model, is about 1.83W / kg to 0.016W / kg and is within the standard value.
  1. The units of measurement for electromagnetic waves are: watts “W”, milliwatts “mW”, and microwatts “μW”.
  2. Watts (W) is the unit of power, refers to the energy emitted per unit. 1 watts = 103 milliwatts = 106 microwatts.
  3. The frequencies of a cellular base station are microwave (MW) and radio waves. The frequencies are usually measured as the power density of a plane wave, typically written in μW / cm2 (microwatt / cm2).
  1. Radio waves are at the lowest range of the EM spectrum, with frequencies of up to about 30 billion hertz, or 30 gigahertz (GHz), and wavelengths greater than about 10 millimeters (0.4 inches). Radio is used primarily for communications including voice, data, and entertainment media. For example, when you take a taxi, you can hear the radio contact, the Bluetooth earphone for driving, the wireless helper that picks up phone calls, and so on, which are all common electromagnetic wave applications.
  2. Microwaves fall in the range of the EM spectrum between radio and IR. They have frequencies from about 3 GHz up to about 30 trillion hertz, or 30 terahertz (THz). They have wavelengths from about 10 mm (0.4 inches) to 100 micrometers (μm), or 0.004 inches. Microwaves are used for high-bandwidth communications, radar and as a heat source for microwave ovens and industrial applications.
  3. Infrared radiation is in the range of the EM spectrum between microwaves and visible light. IR has frequencies from about 30 THz up to about 400 THz and wavelengths of about 100 μm (0.004 inches) to 740 nanometers (nm), or 0.00003 inches. IR light is invisible to human eyes and, we can feel its heat if the intensity is sufficient. For example, TV remote control, cold weather heaters, leisurely travel card for traffic and shopping, are all infrared applications.
  4. Ultraviolet light is in the range of the EM spectrum between visible light and X-rays. It has frequencies of about 8 × 1014 to 3 × 1016 Hz and wavelengths of about 380 nm (.000015 inches) to about 10 nm (0.0000004 inches). UV light is a component of sunlight and; it is invisible to the human eye. It has numerous medical and industrial applications, but it can damage living tissue. The X-ray has frequencies of 1017 ~ 1018HZ electromagnetic waves. It has the properties of penetrating substances and is often used for medical examination. Therefore, doctors can see inside the human body.
It will not interfere with the function of home appliances. Base stations and various types of household appliances use different frequencies and, it will not cause interference problems. The table below showcases the different electromagnetic waves in household appliances.
 
The power of the base station electromagnetic wave is low.
  1. Our mobile network is based on the cellular network system. The system is composed by many sub-areas, and each of the sub-areas is served with one base station. The base station's antennas keep service at low power and the proper distance between the systems allows other base station antennas to reuse the same radio resource.
  2. When the system adds many new base stations, the service area of a base station is smaller. Base station output power, thereafter, will also be decreased. Therefore, in a high-density metropolitan area, the smaller the service area is, the lower the transmission power.
No, it does not cause environmental pollution. According to the press by the EPD (Environmental Protection Department) on April 25, 2000, the electromagnetic waves emitted by the base stations are definitely non-ionizing radiation. (reference Q1 what is electromagnetic wave ? ) The EPD also assign studies to the relevant academic research institutes. All the studies are shown: the electromagnetic waves of the domestic base station are below the international standard. The human body will not be harm. Therefore, the domestic base station is not listed as factors of environmental pollution.
  1. The base station electromagnetic waves are restricted by our government. To know if the waves are over standard, a third party legally licensed by our government is required. Usually, a third party measures waves with professional equipment, and the results must be compared with standard SAR value.
  2. The National Communications Commission also provides free base station wave testing services to public at the phone no. 0800-580-010. Other service organizations/ companies/ institutes recommended by the National Communications Commission are also listed below for reference.