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Motion of the Council of Allegheny County urging the Allegheny County Health Department to consider the implementation of mask mandates for indoor gatherings within Allegheny County at any time(s) at which the County’s COVID-19/SARS-CoV-2 transmission rate becomes “moderate” (as defined by the Centers for Disease Control), and strongly encouraging County residents and employers to facilitate vaccination to the greatest extent possible.
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WHEREAS, the Centers for Disease Control (CDC) clearly and eloquently summarized many of the benefits of masking in their publication The Science of Masking to Control COVID-19, CDC, 11/16/20 (attached); and
WHEREAS, among the findings made by the CDC are the following:
· Infection is spread primarily through exposure to respiratory droplets exhaled by infected people when they breathe, talk, cough, sneeze, or sing.
a. Most of these droplets are <10 µm, often referred to as aerosols.
b. The amount of these fine droplets and particles increases with volume of speech (e.g., loud talking, shouting) and respiratory exertion (e.g., exercise).
· 40-45% of infected people are estimated to never develop symptoms, and among people who do develop symptomatic illness:
a. Transmission risk peaks in the days just before symptom onset (presymptomatic infection) and for a few days thereafter.
b. Accordingly, the number of infections transmitted peaks when virus levels peak.
· Most SARS-CoV-2 infections are spread by people without symptoms.
a. CDC and others estimate that more than 50% of all infections are transmitted from people who are not exhibiting symptoms.
b. This means, at least half of new infections come from people likely unaware they are infectious to others.
· Cloth masks provide source control, by containing exhaled droplets.
a. Cloth masks block most large (>20-30 µm) exhaled respiratory droplets.
b. Multi-layer cloth masks substantially block respiratory droplets <1-10 µm - Comprise the greates...
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