October 17, 2015
This construction Q&A addresses the broader issues of radiofrequency radiation from the perspective of construction and maintenance workers who may need to work near antennas used for cellular and other personal communications services.
Radiofrequency (RF) radiation refers to energy that transmits wireless information with frequencies between 3 kilohertz (kHz) to 300 gigahertz (GHz).
RF energy is essential for telecommunications services such as radio and television broadcasts, cellular telephones, microwave point-to-point links, and satellite communications.
RF energy is released by the movement of electrical charges in transmitting antennas. Transmitting antennas come in different shapes and sizes and emit RF radiation in different directions, up to 360 degrees.
Low-level RF radiation it is not considered hazardous. However, high levels of RF radiation generate heat in water-rich substances, including human tissue. It’s the same principle by which microwave ovens cook food. In humans, high exposure levels can produce symptoms called “thermal effects” due to the ability of RF energy to rapidly heat tissue; reddening of the skin and burns are examples.
Two parts of the body – the eyes and the testes – are particularly vulnerable to RF heating because of their relative lack of blood flow to dissipate excess heat. Also, people with active electronic implantable medical devices (pacemakers and insulin pumps, for example) should not enter areas where exposure to RF radiation is possible without first consulting their doctor.
Access to antennas that transmit high levels of RF radiation is generally restricted so that the public is not exposed to high-level RF radiation. But it is possible for workers to be exposed if they work near RF-generating antennas.
That’s most likely to happen near antennas used for cellular and other personal communications services because they are often located on rooftops, the sides of buildings, and other elevated structures in urban and suburban areas. These antennas are typically rectangular panels arranged in groups. Other antennas are designed to blend into their surroundings and workers may not be aware of them. However, not all of these antennas transmit RF energy; some may be receivers.
The RF energy that could be radiated by cellular and other personal communications services antennas depends on the number of transmitters, the power of each transmitter, and the type of antenna. Generally, the highest exposure levels are at the same height and directly in front of the antenna, but the exposure levels rapidly decrease with distance.
In the United States, the Federal Communications Commission has adopted safety guidelines for evaluating RF exposures, based on recommendations of the National Council on Radiation Protection and Measurements and the Institute of Electrical and Electronics Engineers.
The FCC’s exposure guidelines depend upon the electric and magnetic field strength and power density of the transmitter, so the only way to accurately measure your exposure to RF radiation is with a personal RF monitor. A personal RF monitor can be helpful when you need to work where RF exposures are possible, but you need to learn how to use it and understand how to interpret RF exposure levels.
Does Oregon OSHA have health and safety rules covering exposure to RF radiation?
Oregon OSHA does not have rules covering exposure to RF radiation.
A personal RF monitor can warn you if you are in an area where RF radiation is at a dangerous level, based on the FCC’s exposure guidelines.
If you don’t have an RF monitor, these tips can help you:
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