In a letter directed to the medical community, to the WHO and the CDC released on July 6, Dr. Don Milton, professor of applied environmental health in the University of Maryland School of Public Health, was joined by 239 scientific colleagues from 32 countries in urging these bodies to recognize the potential for airborne spread of COVID-19 and to do more to communicate this risk and advocate for the widespread use of preventive measures.
In one of many interviews about the recommendations the group made based on studies by the signatories and other scientists which have demonstrated "beyond any reasonable doubt that viruses are released during exhalation, talking, and coughing in microdroplets small enough to remain aloft in air and pose a risk of exposure at distances beyond 1 to 2 m from an infected individual," he expresses dismay about how the WHO has downplayed the role of airborne transmission which means there has not been as much attention to the importance of ventilation and mask-wearing as there ought to be.