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Want to improve employee health? Improve indoor air quality

EPA encourages businesses to improve indoor air quality

By Jeff Levin-Scherz, MD, MBA | April 5, 2022

Ensuring pure indoor air is one way employers can help protect employees from COVID-19 and other transmissible illnesses, regardless of their immune status and willingness to be vaccinated.
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About the series

“Dr. Jeff Levin-Scherz provides regular updates on the latest COVID-19 developments with a focus on the implications for employers and guidance on how they can tackle pandemic-related challenges to keep their workplaces safe. Explore the series.

Case rates in the U.S. continue to decline, although we see an uptick in reported new COVID-19 cases in the Northeast. The Omicron strain BA.2 continues to gain steam; it now represents almost 60% of new cases, and close to three-quarters of cases in New England and the New York area. Hospitalizations are declining in almost all states, and U.S. COVID-19 hospitalization rates (about 1,500 a day) are the lowest since early in the pandemic. Wastewater surveillance reported by the Centers for Disease Control and Prevention (CDC) continues to paint a mixed picture; 207 sites report a decrease in viral particles detected while 248 report an increase.

The Institute for Health Metrics Evaluation at the University of Washington projects continuing declines in new COVID-19 cases through mid-summer, although many experts expect a second Omicron wave. Immunity from a combination of vaccination and immunization is high, so a wave of hospitalizations and deaths similar to the first Omicron wave in early winter is less likely.

Implications for employers
  • In most geographies, the danger of returning to the workplace remains low.
  • Employers should continue to make all employees feel comfortable wearing masks, regardless of immunity status.
  • Businesses should consider practical approaches now to mitigate future risks.

Cleaner indoor air can help prevent spread of COVID-19 – and more

The best way to prevent transmission of illness is through environmental approaches that require little or, best of all, no action on the part of individuals. Employees get the health benefits of clean indoor air without having to put on masks or change their behavior.

There are three basic ways to decrease transmission through improving indoor air quality:

  1. Ventilation: Opening windows is a straightforward way to improve indoor air quality, especially in our homes. But most newer buildings do not permit open windows for safety and energy efficiency reasons, and instead have air handling systems that bring in outdoor air. Changes in settings can often increase air exchanges with very little cost.
  2. Filtration: High effectiveness filters help remove viral and other particles from the air and can lower the risk of COVID-19 transmission. These filters also remove chemicals that cause offensive odors and particulate matter that increases the risk of heart and lung disease. For some buildings, filtration is a less expensive way to increase indoor air quality.
  3. Disinfection: Systems that expose air to ultraviolet (UV) irradiation can also reduce viral transmission, although some have not been shown to be useful, and humans should not be directly exposed to UV-C light.

A study from over 10,000 classrooms in Italy showed that the rate of COVID-19 infections was cut by 80% in classrooms with more than six air exchanges per hour compared to those with stagnant air.

When air exchange occurred six times per hour, infection rates were reduced to 17.5 per hour (from 100 with zero air exchange).
Infection rate decline in classrooms with more air exchange

Source: David Hume Foundation

Ensuring high quality indoor air can help employers protect all employees regardless of their immune status and their willingness to be vaccinated and boosted. Cleaner indoor air also means less spread of other respiratory diseases, including influenza and tuberculosis. The Environmental Protection Agency has issued the Clean Air in Buildings Challenge encouraging businesses to take action to improve indoor air quality, and the White House has announced that funds from the American Rescue Plan and the Bipartisan Infrastructure Law might be available to help companies make investments to improve their indoor air.

Studies show that breathing cleaner air can not only prevent infections but also can also improve attention and performance. Children in Georgia who were switched from diesel to electric school buses had higher test scores.

Implications for employers
  • Evaluating and improving indoor air quality can reduce risk of COVID-19 exposure and can also make workplaces more pleasant. It might improve worker productivity too.
  • Employers that make improvements to indoor air should communicate this to employees. Employees who feel that their employers are making efforts to keep them safe are more productive and less likely to leave.

FDA and CDC authorize second booster shot

The Food and Drug Administration (FDA) and the CDC authorized a second booster shot for those over age 50 and for the immunocompromised to be administered at least four months after the last vaccination. Both agencies made this decision without convening panels of outside experts after two studies showed that second boosters increased immunity and decreased hospitalization and severe illness in these groups. Those who got a second booster in this large study with short follow-up had four to five times fewer deaths. The CDC fell short of recommending the second booster – but rather says those over age 50 and those over age 12 with compromised immune systems are eligible for a second booster.

For individuals the risk associated with a booster is very low, and the potential benefit is substantial for those over age 60 and those with diseases or drug treatment that could impair their immune systems. But the benefits are likely smaller for those who are already up to date on vaccination (boosted) and had a recent COVID-19 infection.

I’m in the age group now eligible for a booster, and for my own safety and the safety of those around me I’ve already gotten mine.

Current CDC guidelines

Sources: CDC: COVID-19 Vaccine Boosters and COVID-19 Vaccines for Moderately or Severely Immunocompromised People

Age Primary series option First booster Second booster Immuno-compromised
<5 No vaccine available yet
5 to 11 2 Pfizer Not recommended Not recommended Third primary dose but no booster (3 total)
12 to 17 2 Pfizer Pfizer only Not recommended Third primary dose and 2 boosters (5 total)
18 to 50 2 Pfizer,
2 Moderna
or 1 J&J
Pfizer or Moderna Not recommended Third primary dose and 2 boosters (5 total)
50+ 2 Pfizer,
2 Moderna
or 1 J&J
Pfizer or Moderna Pfizer or Moderna
Third primary dose and 2 boosters (5 total)
Implications for employers
  • The second booster shot offers enhanced protection, especially for those at increased risk of COVID-19, but the primary series and first booster prevent the most COVID-19 cases and hospitalization and death.
  • Employers can continue to encourage vaccination, including boosters, by offering paid time off for vaccination.
  • Vaccinations are now widely available, and there should be little wait time in most locations; shows seven pharmacies with available appointments for vaccines within two miles of my home in suburban Boston.
  • The Biden administration had signaled that it would run out of money to purchase vaccines later this year, but it now appears a Congressional bill to replenish supplies of vaccine and COVID-19 treatment is likely to pass Congress later this month.

Population Health Leader, Health and Benefits, North America

Jeff is an internal medicine physician and has led WTW’s clinical response to COVID-19 and other health-related topics. He has served in leadership roles in provider organizations and a health plan and is an Assistant Professor at Harvard Chan School of Public Health.

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