LOS ANGELES—A deal has been struck between the unions representing casts and crews and major studios on the specific protocols that will be put in place for the TV and film industries to safely resume production during the COVID-19 pandemic.

Agreeing to the deal are the Directors Guild of America (DGA), International Alliance of Theatrical Stage Employees (IATSE), International Brotherhood of Teamsters (IBT) and the Basic Crafts and Screen Actors Guild-American Federation of Television and Radio Artists (SAG-AFTRA) with the Alliance of Motion Picture and Television Producers (AMPTP).

The negotiations spent months developing science-based protocols designed to minimize the risk of transmission, with the unique environments of TV and film production in mind. Among the guiding principles, which were based on “The Safe Way Forward” report released by unions back in June, include testing regimens, safety protocols, a zone-based system and use of personal protective equipment (PPE).

PLUS: Staying Safe on Set

As part of the agreement, every member of the cast and crew will be tested before their first day of work and will then subsequently undergo a regular testing protocol during the production. Productions will use Lab-based PCR test or rapid PCR tests in conjunction with lab-based PCR; antigen and antibody tests are not acceptable.

The “zone” system outlined in the deal lays out barriers in which those on set can flow based on proximity to cast, level of testing, PPE and the extent to which physical distancing can be observed. 

Zone A includes performers—who are not able to utilize PPE or physical distancing when cameras are rolling—and those that come in close contact with performers; Zone A requires testing at least three times a week.

All other individuals in the production environment are required to utilize physical distancing and PPE at all times. They are broken into three different zones: Zone B includes those who work on set but not when performers are present without PPE and requires testing once a week; Zone C covers workers in production areas other than the set and must be tested at a minimum of once every two weeks; and Zone D covers remote workers associated with the production but not working in the production environment, and requires a test prior to their first day of employment.

The deal also stipulates that each production must have a designated COVID-19 compliance supervisor.

In the event that an employee has a positive test or shows other possible signs of COVID, they will receive 10 days of COVID-19 paid sick leave; the employee will be reinstated once they have been cleared to return to work. In addition, employees that are required to quarantine or isolate at the request of an employer, or as required by law, will receive quarantine pay.

“This agreement establishes sensible, science-based protocols that allow members to return to doing the work they love while managing risk,” said Gabrielle Carteris, president of SAG-AFTRA. “I am grateful to our sister unions, who pulled together during this extended crisis, as well as to the studios for collaborating on this important issue.”

Additional information on the guidelines can be found on the union websites. 

COLUMBIA, Md.—By his own admission, Richard Tell has climbed lots of broadcast towers, gotten himself exposed to some really intense radio frequency fields, suffered RF burns and on occasion has even (accidentally) burned out “some fancy test equipment,” but “never to my knowledge experienced a health effect from my work in RF fields, except for the burns.”

Tell, now 75, and an industry expert in the effects of RF radiation on the human body, shared some of his experiences and deep knowledge of the subject at an RF safety seminar put together by the Washington, D.C., and Baltimore SBE chapters under the auspices of Fred Williard, an officer of the D.C. chapter, and hosted by Rohde & Schwarz at their North American headquarters and training facility.

Tell’s presentation—“Staying Safe In RF Fields”—was tailored to provide broadcast engineering personnel and others involved in RF work with the knowledge they need to stay safe and prevent injury. The free day-long course attracted transmitter operators, station and broadcast group personnel, consulting engineers, network employees, two-way radio service technicians, government and military employees, amateur radio operators and even a SiriusXM satellite radio representative from as far away as New York and Richmond, Va.

Tell, an IEEE Life Fellow and chair of RF safety-related committees within IEEE, spent some 20 years with the federal government, working for the Center for Devices and Radiological Health, and later serving as chief of U.S. Environmental Protection Agency’s Electromagnetics Branch, and providing technical support to the FCC when that agency was setting new rules for human exposure to RF fields.

His 52-year-long career not only includes laboratory work and computer modeling, but also plenty of “hands-on” experience—including purposefully subjecting himself to RF currents—that makes him uniquely qualified to impart knowledge and field inquiries into this sometimes rather gray area of radio and TV station operations.

WHERE THE DANGER LIES

In setting the stage for the “practical” portion of his presentation, Tell provided a definition of “MPE,” or Maximum Permissible Exposure (“according to the FCC, this is the amount of field exposure outside the body that is considered safe”), and “SAR,” or Specific Absorption Rate (“the rate at which RF is absorbed in the body, and which is the basis for our safety standards”).

He also distinguished between ionizing and non-ionizing radiation—terms that confuse many lay people and even some professionals. Ionizing radiation occurs when there’s sufficient energy to remove electrons from an atom typically associated with very penetrating radiations, such as x-ray and gamma; non-ionizing refers to any other type of electromagnetic radiation, including the radio frequency spectrum.

“Radio waves do not have sufficient energy to ionize atoms,” said Tell, assuring course attendees that this was not something they had to worry about. “RF fields are not the same as ionizing radiation. They cannot ionize tissue, and unlike ionizing radiation, the biological effects are not cumulative.”

Tell explained that aside from burns suffered from contacting RF-energized conductors, the greatest effect of radio waves on living organisms was heating of tissues, noting that 60 years of research on the effects of RF exposure has established, among other things, that when RF levels fall below a certain threshold, there is no measurable effect on human bodies. Such research has also established a useful “threshold” for what constitutes an excessive RF level.

“The most sensitive and reliable indicator of an established and potentially adverse biological effect of RF radiation exposure has been behavioral disruption of a learned task in laboratory animals,” said Tell. “Their performance ‘slacks off’ because they are ‘warming up’ and less inclined to do what they were trained to do.”

He noted that the threshold for such behavior modification began at a SAR of about 4W per kilogram of body weight, and that this exposure level had been extrapolated to humans and adopted by the FCC in its regulations limiting exposure. Tell stated that a safety factor of 10 is used to constitute what is considered “safe,” with 50 times less exposure being “safer than safe.”

Tell said that in calculating what a “0.4W/kg safe” exposure would be for a 180-pound individual, it amounts to 33W distributed within the tissues. He noted that the normal metabolic rate for humans at rest is about 105W.

“When RF energy is delivered to a lossy material such as body tissue, it produces heating of those tissues,” he said. “Elimination of heating of the body is the primary objective of most safety regulations today.”

Tell observed that the effects of RF on the body are not uniform, with some areas being heated more than others, and that this heating is frequency-dependent, as humans resonate at around 65 MHz.

“FCC exposure limits are based on limiting the rate at which RF energy is absorbed in terms of watts per kilogram of body mass so that you don’t warm up,” said Tell. “A hazardous level of exposure is reached when you begin to warm up from the RF energy impinging on your body.

“The ‘take-home’ here is that if you feel warmer than you suspect would be normal, back off and ensure that your exposure is within the accepted limits.”

PROTECTIVE MEASURES

Tell noted that portable “clip-on” RF monitors, while not necessarily precise indicators, do provide “early warning” information that is useful in flagging what may lead to excessive exposure in RF environments. He also provided some tips for proper use of such monitoring devices, as well as suggestions for mitigating one’s exposure.

“Always wear an RF monitor on the front of your shirt; it should face the antennas generating the radiation you’ll be exposed to,” said Tell. “The difference between front and back can amount to a factor of 16 at 100 MHz. If the monitor sounds only occasionally that’s not a problem. If it’s steady, then it’s time to get out of the area.

“If you have to work close to a high-power antenna, use a personal monitor to determine if the area is below the exposure level; if not, the transmitter must be shut down and locked/tagged out, especially if it’s remotely operated. Take the lockout key with you until all work is completed and the system can be returned to normal operation.”

Other tips include staying behind directional antennas when doing tower work and exercising care when working around non-directional radiators.

“You cannot hide behind an omnidirectional antenna like you can a dish, a Yagi or a panel antenna,” Tell said.

He observed that there were some cases where broadcast operations could not be interrupted and doing work around such transmission sites called for operating with reduced power or wearing a protective body suit and hood designed to attenuate RF exposure to the body.

“Such a suit greatly reduces RF exposure,” said Tell. “But always remember that the suit does not make you into Superman.”

WATERTOWN, S.D.—The latest video of the National Association of Tower Erector’s Climber Connection campaign is now available. The new video focuses on RF and antenna identification safety.

The video outlines the FCC’s guidelines for maximum permissible RF exposure limits in both controlled and uncontrolled environments. Testimonial footage is also provided from a tower technician discussing thermal and health effects of RF exposure, as well as the importance of antenna identification when assessing RF hazards. Best practice tips for safety around different types of antennas are also included.

The RF and antenna identification safety video is available to watch here. NATE encourages tower technicians to share the video on social media sites using the hashtag #ClimberConnection.

Previous videos released by NATE as part of the Climber Connection campaign can be accessed here. Topics include PPE inspection, 100 percent tie-off, capstan hoist and rigging, workforce professionalism, tower inspection, gravity and weather conditions.

LAS VEGAS—Using the 2016 International Wireless Communications Expo as its platform, the National Association of Tower Erectors released a new Capstan Hoist and Rigging safety video as part of its “Climber Connection” campaign.

In the video, NATE highlights safety tips for selecting and using capstan hoists. There is also a recorded testimonial from a tower climber on performing function tests, checking manufacturer’s guidelines and emphasizing best practices for using a capstan hoist. In addition, the vide features real footage of capstan hoists in use lifting antenna equipment.

The NATE Member Services Committee says it developed the “Climber Connection” campaign in conjunction with the NATE Safety and Education Committee to provide resources and deliver the association’s message directly to the work force. This is third of 12 planned video releases that will be part of the “Climber Connection” campaign; each will focus on a specific safety topic or issue involving working at heights. NATE previously released videos on PPE inspection and 100 percent tie-off.

To see the capstan hoist and rigging video, click here.

Javier Castillo

ALEXANDRIA, VA—Lightning is one of nature’s most impressive displays of destructive power. Loud and visually overwhelming at times, lightning is chaotically beautiful.

No one knows this more than engineers who work for broadcasters with tall towers in locations where lightning is common. I personally witnessed lightning striking the Empire State Building three times during a storm, and it was pretty awesome to see.

Any operation that relies on a tower knows that it needs lightning protection, but how often do these safeguards need to be checked, maintained and replaced?

Javier Castillo is a lightning expert with LBA, a Greenville, N.C.-based consulting firm focusing on RF and wireless communications and applications. He has spent nearly 25 years consulting on lightning protection solutions worldwide and over the decades, has created proven hardware designs and lightning protection solutions. He has also served as an expert panelist and presenter on lightning protection before entities and groups in nearly every country in Latin America.

We talked to Javier about the best way to prepare for lightning.

A lightning bolt strikes the CN Tower in Toronto in 2008. (Photo credit: Flickr)

BE Extra: Broadcasters generally have tall towers that attract lightning, and lightning protection is taken seriously in this industry. But how often does a modern lightning protection system need to be checked and maintained? Are there any particular things to look for to determine that maintenance is needed right away?

Castillo: We suggest a visual inspection after major storms or observed lightning strikes. Lightning strike counters attached to the structure can be helpful. An annual visual inspection for arc burns or compromises to lighting or other systems, and a check of ground system integrity is also recommended. Microwave, STLs and similar systems on towers are more prone to deterioration and long-term damage from strikes than are high power systems.

BE Extra: The lightning rod has long been used to attract lightning and get the static charge to flow where you want it to flow instead of where it wants to flow. However, there are also systems that make an object (such as a tower) less likely to attract lightning. How does a system like that work? Is it appropriate for broadcasters?

Castillo: Static dissipation systems have emerged as useful to reducing the possibilities of strikes to protected towers. Anecdotal experience has shown them to be effective in averting as many as 90 percent of potential strikes. They are most effective when combined with conventional lightning rods that channel any strikes that do occur. Static dissipation systems should be customized to a particular tower and its appurtenances. (A paper on selection of static dissipaters is at here.)

BE Extra: Lightning also hits power lines and can flow into a building on electrical service wires. What can be done here to protect sensitive equipment inside a building from a power line strike?

Castillo: Proper grounding of all equipment, structures, and power components is essential. This is a complex subject and very site specific. There are many references on equipment grounding, in addition to the National Electrical Code and National Fire Protection lightning guidance. We recommend that station engineers study these references to ensure that their systems are safe and effective.

One of many LBA Lightning Protectors. 

Click on the Image to Enlarge

BE Extra: If you’re a broadcaster with a tall and properly protected tower, where’s the safest place to be during a bad lightning storm?

Castillo: The safest place is in a building or vehicle under the tower and guy wires. These form a protective Faraday cage. However, don’t touch metal objects or stand or lay on the ground as so called “step voltages” in the ground can rise to killer levels during a strike!

BE Extra: If you know a bad storm is coming, are there any extra precautions that can be taken to prevent injuries, loss of life and damage to property?

Castillo: In a well-protected transmitter site, you shouldn’t have to take any special precautions. As a general matter, unused transmission lines should stay grounded, and unused equipment could be disconnected and unplugged.

BE Extra: Is there anything else we should know about lightning and lightning protection?

Castillo: Often overlooked is the safety of news teams, remote broadcasts and other outdoor station activities. Some outdoor equipment like satellite dishes and temporarily located production vans can be protected with lightning masts, but most other activities should be secured when thunder is heard, and shelter sought. Most newsgathering vehicles are safe if STL masts are lowered.