Aerosol transmission refers to the situation when the respiratory droplets lose water in the air, and the leftover proteins and pathogens form nuclei or dust float far away in the form of aerosols, causing long-distance transmissions, according to China's National Health Commission.

But aerosol transmission is not a major route for the spread of COVID-19.

The latest diagnosis and treatment program of the novel coronavirus pneumonia (COVID-19) published on Wednesday said that respiratory droplets and close contact are the main routes of transmission, and added that aerosol transmission is possible only under the conditions of long exposure at high concentrations of aerosols in a relatively enclosed environment, suggesting low possibility of aerosol transmission in daily life.

"That is to say, aerosol transmission is conditional," said Wang Guiqiang, director of Infectious Disease Department of Peking University's No. 1 Hospital.

In confined spaces with concentrated novel coronavirus patients, such as the wards of severe cases, aerosols of the virus may be formed in the air during intubation and ventilator treatment, said Li Taisheng, director of Infectious Diseases Department at Peking Union Medical College Hospital. But the general public does not need to be overly worried about this, and should just keep in mind to "open windows at home often for ventilation."

Wang Chen, Chinese respiratory expert and vice president of the Chinese Academy of Engineering, also highlighted ventilation, saying it's important for people to "keep a certain distance" and not be in a crowded environment.

In addition, Wang said the transmission is also related to wind direction.