News Release

Indoor Air Quality and Covid: A Federal Response Finally Gains Momentum


The White House’s recent emphasis on improving indoor air quality to reduce virus transmission has been praised by public health experts. Linsey Marr and Jose-Luis Jimenez, two scientists who recently co-authored a piece for Time magazine on air quality and Covid-19, have argued that at the beginning of the pandemic, major public health agencies like the CDC and WHO failed to communicate that the spread of the virus is significantly driven by airborne transmission. They focused on spread via respiratory droplets rather than aerosols. These communication failures, write Marr and Jimenez, still “haunt” the U.S.: Mask mandates have been dropped across the country, for instance, but less useful public health measures––such as sanitizing and social distancing––persist. 

LINSEY MARR, PhD,, @linseymarr 
    Marr is a professor of Civil and Environmental Engineering at Virginia Tech and studies viruses in the air. 

Marr told the Institute for Public Accuracy that she hopes the administration’s new focus will nudge localities to adopt the American Society of Heating, Refrigerating and Air-Conditioning Engineers’ standards and guidance into building codes (making such standards and guidance enforceable), and lead to new policies on indoor air quality.

As adjustments are made for the duration of the pandemic and beyond, it will also be important for the public to understand how we got to this place. Marr and Jimenez write that use of the word “airborne” was initially avoided because the word is associated with a “rigid set of protective methods” for hospitals––which have much better air quality than most other indoor spaces. Declaring the virus airborne in hospitals would have, among other precautions, required the use of N95 masks for physicians that were in short supply at the time. Marr told IPA that there were concerns about the “availability of resources, such as N95s, to protect healthcare workers.”

It is unclear whether hospitals and the hospital industry played any role in pushing for the use of different language. But Marr said today that it is “clear that the WHO and CDC wanted to avoid using the word ‘airborne.’ There were infection prevention and control specialists, who are the people in charge of overseeing the use of precautions to protect workers and patients in hospitals, who strongly denied that Covid-19 was airborne.

  “I think hospital definitions were deemed most important [to defining ‘airborne’] because it was medical doctors and others closely associated with hospitals who were driving the discussion about transmission and intervention.” 

Jimenez told IPA that these issues are structural; scientists who study how viruses behave have been shut out from pandemic response. “The people in charge of these decisions at the WHO and CDC tend to have a similar background and work at hospitals. For example, at the WHO, there is an Infection Prevention and Control Committee that reviews the science and decides how the virus is transmitted and how to prevent infection. It seems that everybody in that committee who took part in these discussions worked at a hospital… There was a pretty uniform background of the people making the decisions.”