The use of cellular antennas and other radio frequency (RF) generating devices has grown drastically over the past 30 years, driven by increased demand for cellular service. Since 1985, worldwide cellular subscriber connections have risen to more than 375 million. The number of cellular antenna sites is more than 300,000. This has created health concerns about RF radiation exposure.
What is RF radiation?
Radiation is a form of electromagnetic energy. It can be ionizing or non-ionizing. Ionizing radiation has more energy than non-ionizing, and it has enough energy to break chemical bonds and cause biochemical changes. It can be found in nuclear energy plants, weapons facilities and hospitals.
Non-ionizing radiation causes vibration in molecules to generate heat. RF radiation is a form of non-ionizing radiation—as is extremely low-frequency (ELF) radiation—emitted from electric currents, overhead power lines and other equipment powered by electricity. It comprises radio waves and microwaves characterized by wavelength and frequency. RF radiation has a higher frequency than ELF.
What’s the frequency?
Typically, signals that have longer wavelengths travel a greater distance and can penetrate through and around objects more effectively than higher frequency signals that tend to have shorter wavelengths.
According to the Centers for Disease Control and Prevention, “Even though [ELF and RF] are both non-ionizing radiation, RF radiation is much higher frequency than ELF radiation and therefore potentially more harmful.”
The Federal Communications Commission has indicated that frequencies between 30 and 300 megahertz pose the biggest risk to humans because the body most efficiently absorbs that range of radiation.
RF radiation is an invisible hazard and can’t be seen, smelled or touched. It is commonly used in microwave ovens, radar, industrial heating and sealing processes, medical applications, telecommunications and broadcast equipment. It is also used in cellular antennas, radio and television broadcasting, radio communications for first responders, microwave point-to-point radio links and satellite communications.
Effects of RF exposure
The most concerning exposure to RF radiation is in telecommunications equipment because of these devices’ locations. They are often installed or located on rooftops, the sides of buildings or other elevated structures where work is conducted by electricians, lineworkers, HVAC contractors and other construction industry workers.
According to OSHA, the thermal effects of exposure to RF radiation at sufficiently high-power densities can cause blindness and sterility. This occurs when the body is unable to handle the heat buildup caused by RF radiation.
Other symptoms of overexposure may include difficulty breathing, sweating, body aches, diarrhea, skin erythema (redness, usually blotchy red spots), headache, numbness, paresthesia (tingling or numbness, skin crawling or itching) and malaise or an overall sense of feeling mentally or physically unwell. Workers can also suffer severe burns if they come into direct contact with an antenna because the equipment is often energized.
Workers can protect themselves from RF-emitting equipment by adhering to instructions on signs and barriers; using personal RF monitors and protective clothing when work cannot be done at a safe distance; understanding the risks of having a pacemaker or other medically implanted device around radiation-generating devices; and keeping away from antennas. Employees should stay at least 6 feet away from an antenna and at least 10 feet away from a cluster.
Although little is known about the long-term and nonthermal effects of RF radiation, there is evidence that it can disrupt the human body’s circadian rhythms, immune system and the nature of the electrical and chemical signals communicated through the cells.
According to the Center for Construction Research and Training: RF Awareness Program for the Construction Industry, “The short-term thermal effects of RF radiation on humans are well-documented. But less is known about the long-term health effects. The existing research has focused on the health risks associated with cellphone use and the public’s exposure at ground level from RF radiation emitted from antennas located on rooftops, sides of structures, or towers. At this time, no available research has focused on occupational exposures to RF radiation among construction workers.”
The program was designed to increase industry awareness on how to identify the hazard, the risks associated and safe work practices. It was created by the Roofing Partnership and the multitrade, labor-management RF Radiation Work Group.