Although many experts from Dr. Fauci to the World Health Organization initially discouraged healthy people from wearing masks, it seemed to me that wearing a face covering should diminish the spread of infection of diseases that are communicated through the air.  Therefore, I was surprised last month when I read the California Department of Public Health's tepid justification for requiring Californians to wear face masks inside any public space and other "high risk" situations:

"There is scientific evidence to suggest that use of cloth face coverings by the public during a pandemic could help reduce disease transmission." (emphasis added)

Why, I wondered, did the Department say only that there is "scientific evidence" and not actual "scientific studies"?  Why did it say that this evidence "suggests" rather than "has found"?  Why did the Department say only that face coverings "could help" rather than "reduce" disease transmission?  "Disease", moreover, can be caused by a wide variety of bacteria and viruses.  Does any of this evidence have application to corona viruses in particular? 

Because as a layperson I believe that face coverings are likely to reduce airborne disease transmission, I wanted to get to the bottom of the Department's tentativeness.  On June 18, 2020, I submitted the following request to the Department under California's Public Records Act:

"A list of all scientific studies actually reviewed by the Department to support its statement in the updated Covid-19 face mask guidance that scientific evidence suggests that wearing a cloth face mask could help prevent the spread of disease."

Because the Department had issued guidance stating that there was "evidence", it surely must know the evidence to which it was referring.  The Department responded saying that it needed more time because of the pandemic and to: (i) search for and collect the requested records from field facilities or other establishments separate from the office processing the request; and (ii) search for, collect, and appropriately examine a voluminous amount of separate and distinct records demanded in a single request.  I have yet to receive the requested list. 

Do not misconstrue this post as a taking a position that face coverings are ineffective in limiting the spread of airborne disease or that people should not wear masks.  In these unprecedented times, however, it is important for government agencies to communicate clearly and accurately and be able to support factual claims in a timely manner.