Mitigating Public Safety Risks – Let’s Fly Again!

Dec. 17, 2020
Mitigating health and safety risks, complying with new regulatory requirements and addressing public concerns are key issues for airports and airlines as we struggle through winter.

Air travel is a key driver of the economy and the pandemic has significantly impacted the air travel industry.  Assuring the public that flying is as safe as possible given the pandemic is a challenge for the air travel industry.  Airports around the country are focused on making the right choices to increase public confidence  by mitigating health and safety risks.  While air travel has been modestly increasing over the past few months with more people willing to fly, we have a long way to go to get back to pre-pandemic conditions.  Mitigating health and safety risks, complying with new regulatory requirements and addressing public concerns are key issues for airports and airlines as we struggle through winter.  Addressing concerns and communicating measures to reduce risks are critical to get air travel flying again.

Mitigating public safety risks starts with worker safety and OSHA has some new COVID-19 related guidance.  Based on the OSHA definition of risk in current COVID guidance documents, most airport workers are in the medium or low exposure risk categories.  Those risks are defined as follows:

Medium exposure risk jobs have frequent and/or close contact with, i.e., within six feet of, people who may be, but are not necessarily known to be, infected with SARS-CoV-2. Workers in this risk group may have frequent contact with travelers returning from international locations with widespread COVID-19 transmission. In areas where there is ongoing community transmission, workers in this category include, but are not limited to, those who have frequent and/or close contact with the general public or coworkers.

Lower exposure risk jobs are those having minimal occupational contact with the public and other coworkers. (OSHA)

OSHA enforcement activity related to worker health and safety varies from state to state.  In California, Cal/OSHA has issued dozens of COVID-19 related citations since April 2020 to agencies and businesses, with fines ranging from hundreds of dollars to several hundred thousand dollars.  The most common violations cited by Cal/OSHA for COVID-19 are: 

·       Not having an updated Injury Illness Prevention Program to incorporate COVID-19 safety.

·        Lack of proper COVID-19 safety signage.

·        No, or inadequate employer provided PPE.

·        Lack of proper social distancing or allowing too many people in a building area such that social distancing is difficult.

·        Not placing plexiglass dividers where physical social distancing is not possible.

·        Not providing time for employees to clean and sanitize spaces and wash hands.

·        Lack of employee COVID-19 related training and documentation of such training.

Given the number of citations for the above noted items, it is likely that many employers are not aware of new requirements due to the pandemic response. Employers should update their health and safety programs to incorporate the risks and proper protocols for COVID-19.  Proper PPE must be provided to employees and they need to be trained to use it. Most importantly all efforts should be documented and thorough records of activities should be maintained. An audit by a qualified third party can help verify and document all measures are in order.  Further, communicating with stakeholders that the facility was audited by a qualified third party as verification of health and safety can go a long way toward increasing public confidence.

Early in the pandemic, there was considerable concern about the possibility of the virus surviving on surfaces and people getting sick from touching those surfaces and then touching their eyes, face or mouth.  As such, cleaning and sanitation were an intense early focus of health and safety.    As time has progressed and experts have learned more about the SARS-CoV-2 virus and how it appears to be transmitted, the inhalation of contaminated droplets and/or aerosols are thought to be the most prevalent method of infection.  Although experts now suggest that transmission from contaminated surfaces is not the primary method this virus is spread, cleaning and sanitation remain important today.

The CDC advised increased cleaning and enhanced sanitation procedures for high touch surfaces and common areas. People were very concerned about the potential transmission risk from surfaces so much so that cleaning products were in short supply and high demand in the early months. High touch surfaces and increased cleaning and sanitation have been implemented nearly everywhere to mitigate the risk of contaminated surfaces possibly causing infection from transfer from a contaminated surface by touching with one’s hands and transmission through the eyes, nose or mouth. Enhanced cleaning and sanitation protocols have been developed and implemented across nearly all industries and in most facilities as the pandemic has progressed. The critical components of COVID-19 cleaning and sanitation protocols are to:

·        Follow the CDC recommended guidelines or better.

·        Track and utilize the EPA list of cleaning products ensuring the appropriate dwell or wet time for each chemical/product used.

·        Provide PPE and train employees on proper use.

·        Place appropriate signage in key locations to both meet recommended and required guidance, inform stakeholders, and assure the public regarding actions, activities, and health requirements.

·        Implement a robust training program.

·        Document everything well — the program, the chemicals used and all training.

·        Consider third party verification of your program and its implementation.

·        Communicate to assure the public and stakeholders of actions to ensure clean and sanitized spaces. If you have obtained third party verification, communicate that as well.

Social distancing requirements including signage and markings on the floor to remind people to keep at least six feet of distance are important in areas where people queue for a line, escalators or congregate such as check in counters, checkpoints and baggage claim areas. Plexiglass is a recommended physical barrier where social distancing is not possible and is an OSHA recommended engineered solution for those situations. Plexiglass and masks work together to provide protection from transmission by droplets from infected persons.  The placement and use of plexiglass barriers should take into account the workers tasks as well as the ventilation and flow of air in the space.  Plexiglass can stop droplets from the breath, cough, laugh or sneeze from an infected person, however, plexiglass is not a barrier for aerosol transmission. 

Droplets are small saliva particles of varying sizes which can fall to the ground relatively quickly and are thought to travel within a close range of the individual.  Aerosols, as described by the CDC, are infinitesimal and can travel on air currents potentially for hours.  Both droplets and aerosols carrying SARS-CoV-2 can be emitted from an infected person during normal activities such as speaking, coughing, sneezing, laughing. Both droplets and aerosols are believed to cause airborne transmission of the virus.

As health experts have learned more about how the virus is spread, there has been an increased focus on airborne transmission either through close contact with an infected person or through aerosol transmission by those very small particles that behave like a gas and remain airborne.   Experts currently indicate that exposure time and concentration of the virus particles are key to becoming sick with COVID-19.  In other words, a person would need to be exposed to enough of the virus over a long enough time frame to become ill. Infection requires both time and concentration, although some individuals may be more susceptible to becoming ill than others with a lower dose of viral load.

Recent information has suggested that infection might also occur from multiple short exposures to concentrations of the virus, such as, if a worker is exposed to multiple infectious individuals each for a short duration, that worker could become infected. The infectious dose of SARS-CoV-2 is currently unknown, although various studies have attempted to estimate it.

In addition to social distancing, PPE, sanitization of surfaces and plexiglass barriers, facilities are improving their ventilation systems, adding portable HEPA units near workstations, retrofitting existing building systems with enhanced filtration and other technologies to treat the air and reduce the risk of illness spread.

The Department of Defense conducted aerosol mobility tests inside Boeing aircraft in August of 2020 to assess the distribution of viral particles from an infected person inside an aircraft.  The study used a DNA particle tracing technology together with fluorescent particles as a means to replicate viral particle movement through the aircraft and measure concentrations of potential viral load.  The report indicated the following findings: “Rapid dilution, mixing and purging of aerosol from the index source was observed due to both airframes’ high air exchange rates, downward ventilation design and HEPA-filtered recirculation. Contamination of surfaces from aerosol sources was minimal.” (USTRANSCOM)

The DOD study was able to replicate viral particle movement to assess the aerosol movement during airflight. Using particle diagnostic tools is a meaningful way to provide data to assess conditions and mitigation measures.  While the DOD study has recently added a revision to address potential misinterpretations of the data, including the fact that people on a plane would be moving which would impact air flow in ways the study did not include, the fact remains that the use of aerosol viral particle movement diagnostic tools to provide quantifiable data has tremendous value.

In studies conducted for clients, we have used particle diagnostics to replicate viral movement to assess mitigation measures.  The particles are safe DNA that replicate the size of SARS-CoV-2 virus and are released at concentrations that can be measured and tracked.  Sampling devices mimic inhalation and are placed throughout the space to detect the concentration of DNA particles that reach that area through airborne or aerosol transmission. 

In a large public meeting/hearing auditorium we assessed the position of portable HEPA filtration units and plexiglass barriers as mitigation measures.  Through the use of particle diagnostics we were able to ascertain that in the space where plexiglass had been placed on three sides of a speaker’s seating area at the front of the auditorium that the plexiglass trapped the aerosols at a high concentration and that those aerosols were then spread to other areas of the room, including the rear of the room at concentrations that were not significantly diluted. The HEPA filtration units were useful in the meeting space.

These diagnostic tools are useful. When situating and placing plexiglass barriers and enhanced filtration, they can help identify the best locations to place those mitigation measures and, importantly, if they will enhance healthy conditions or create unintended consequences such as the case with the plexiglass in the auditorium.  Diagnostic tools provide much needed information for decisions on the best use of capital funds, for example, the addition of enhanced filtration or treatment technologies in the air handling units.  Testing, using concentrations of diagnostic particles, can help ascertain where aerosols move and their dilution within spaces and through air handling units which in turn will provide information on what mitigation measures can be most effective.

Public confidence is crucial to increased air travel and getting our economy flying once more.  All the measures airport and airlines take should be documented and some efforts should be shared with the public. Data from diagnostic tests can be used in communications with stakeholders to demonstrate improvements or efficacy of measures.  Data and demonstrations of safety measures taken, 3rd party verifications, and improved building systems can be a very useful in public engagement.

As we look toward a vaccine in 2021, we all are eager to get back to some form of "normal," including more travelling for business and pleasure.   While we cannot fully predict what our new normal will be like, experts are suggesting many of the changes we have seen in 2020 will continue to be with us for several years to come.  There is also some consideration that a vaccine may not fully eradicate this virus, and we will need to remain vigilant against future new emerging pathogens.  As such, the increased focus on health and safety including enhanced air treatment and sanitation is likely going to be with us for some time. 

Lisa Kay is Chief Operating Officer of Environmental Health Sciences Vertical at NV5 where she leads a team of high performing environmental, health, and safety consultants with the mission of delivering solutions and improving lives. NV5 provides engineering and consulting services to airports, government agencies, and companies around the globe.