World Health Organization Director-General Tedros Adhanom Ghebreyesus attends a news conference Friday in Geneva. (Pool/Reuters)

More than 200 scientists from over 30 countries are urging the World Health Organization to take more seriously the possibility of the airborne spread of the novel coronavirus as case numbers rise around the world and surge in the United States.

In a forthcoming paper titled “It is Time to Address Airborne Transmission of Covid-19,” 239 signatories attempt to raise awareness about what they say is growing evidence that the virus can spread indoors through aerosols that linger in the air and can be infectious even in smaller quantities than previously thought.