Do you ever work on rooftops or perform renovation work on the outside of buildings? If so, you may be exposed to an invisible hazard without even realizing it. That hazard is radiofrequency (RF) radiation, and it’s used to transmit wireless information, usually through antennas.

We are increasingly becoming a wireless world, leading to demand for stronger signals and more antennas than ever before. According to the Cellular Telecommunications Industry Association, the number of antennas in the U.S. has nearly doubled over the last 10 years, bringing the total to over 300,000.

RF radiation is not considered a hazard at low levels, but telecommunication equipment such as radio, television and especially cellular antennas, can pose a considerable health risk for exposed workers if not properly controlled.

Why Is RF Radiation Dangerous?

High exposures to RF can heat human tissue in a similar way to how microwaves cook our food. This “thermal effect” can permanently damage tissue, especially the eyes, resulting in cataracts and harmful cognitive health effects. Direct physical contact with antennas can also cause shock and/or burns to the skin. High RF exposures are particularly dangerous because:

• RF radiation is hard to recognize – it is invisible, odorless and tasteless
• By the time workers feel symptoms (e.g., overheating, reddening of the skin) they are already overexposed
• Levels can be low at the start of work and spike without warning
• RF radiation may interfere with medical devices (e.g., pacemakers) and concerns have been raised about possible non-thermal effects (e.g., nerve damage and psychological injuries)

Rooftop and building-mounted antennas can expose nearby workers to high levels of RF radiation. Many antennas are hidden or camouflaged – a practice known as “stealthing.” Knowing this, what can employers and workers in the construction industry do to protect themselves?

Protecting Workers from Overexposure

There are currently no regulations on RF exposure, though a number of organizations have issued recommended exposure levels and best practices. Exposure levels vary based on many factors, but at a minimum, workers should stay six feet away from a single antenna or ten feet away from a group of antennas. Employers should also make sure nearby antennas or those on adjacent buildings are not pointed directly at the work area.

When working on roofs or the sides of buildings where antennas may be present or nearby, workers should do their own visual assessment and ask a supervisor to get more information. Building owners and property managers should have information (or know who to contact) on whether antennas are present, their locations and their RF radiation levels.

Employers must ensure workers potentially exposed to RF radiation have a safe and healthy workplace. For this reason, employers who do this kind of work should have a comprehensive plan for how to prevent overexposures. Listed below are key elements of such a plan adapted from the Institute of Electrical and Electronics Engineers’ Recommended Practice for Radio Frequency Safety Programs, 3 kHz – 300 GHz (C95.7 – 2014).

• Control hazards using engineering controls (e.g., physical barriers such as railings or shielding the source of radiation) and administrative controls (e.g., signage, safe work practices, source power control)
• Identify hazards through exposure assessments or an RF source inventory provided by a building owner
• Train workers to be aware of the hazard, including RF exposure limits and incidence response
• Maintain administrative elements including a written policy, medical surveillance program and safety committee with worker involvement
• Provide and ensure the proper use of personal protective equipment (PPE) as a last resort

As telecommunications equipment becomes more widespread and more powerful, potential exposures to RF radiation will continue to rise. But careful planning by both employers and workers can effectively reduce exposure to this invisible hazard.

[Travis Parsons is the LHSFNA’s Senior Safety & Health Specialist.]