What is the difference between aerosol and droplet transmission? How many meters is the range of aerosol transmission?

There is a certain difference between aerosol and droplet transmission, and aerosol transmission is more terrifying, as it stays in the air longer and covers a wider range. Below, we will look at the specific differences between aerosol and droplet transmission, and how to prevent aerosol transmission of the new coronavirus.

What does aerosol transmission mean?

Aerosols can be simply understood as substances smaller than droplets produced when people sneeze, cough or talk. Droplets can be seen and fall to the ground quickly, while aerosols are so small that they cannot be seen and stay in the air for a very long time. As for the new coronavirus pneumonia, it has not yet been determined whether it is transmitted through aerosols, but there is a data that everyone must know - 20% of the germs can be transmitted through aerosols. Judging from the current infection situation, it is speculated that it may be transmitted through aerosols, so you must not relax your precautions.

How many meters is the aerosol transmission range?

The general meaning of aerosol is: tiny droplets and particles suspended in the air, such as oil smoke, smog, haze, etc.

Aerosol is a colloidal dispersion system formed by small solid or liquid particles dispersed and suspended in a gas. The particle diameter of aerosol is ≤50μm and it can be suspended in the air for a long time, up to several hours.

What is the difference between aerosol and droplet transmission?

Droplet transmission: basically equivalent to transmission through the respiratory tract.

Aerosol transmission: Do you recall this knowledge from high school chemistry?

The medium is gas, the medium is liquid, the medium is mist, and the medium is solid.

Do you remember it?

Aerosol is a colloidal dispersion system formed by small solid or liquid particles dispersed and suspended in a gas medium, also known as a gas dispersion system. Its dispersed phase is small solid or liquid particles with a size of 0.001 to 100 μm, and the dispersion medium is gas. Liquid aerosol is usually called fog, and solid aerosol is usually called smoke.

What is the difference between the two?

Let’s take dentistry as an example.

If a patient with the new coronavirus comes to the dental clinic and asks for a teeth cleaning, it happens that the mask worn by the doctor is an anti-smog mask.

1. When he sneezes, coughs, or talks, saliva accumulates and the doctor inhales it through the respiratory tract and becomes infected. This is called droplet transmission.

2. He cleaned his teeth, and a large amount of water mist appeared in the clinic due to the high-frequency vibration of the ultrasonic cleaning machine head, which was cooled down. The mist mixed with the patient's blood, tiny tartar and saliva into the air to form an aerosol. The doctor may be infected by inhaling it directly during the teeth cleaning process (it may be more appropriate to call it droplet transmission at this time). It is also possible that after the teeth cleaning, the patient has left, but the doctor inhaled the aerosol in the air and was infected. This is called aerosol transmission.

3. A second patient came. This patient did not wear a mask and directly inhaled the blood, saliva, fine tartar and water mist of the previous patient in the clinic to form a dispersed phase aerosol and was infected. This is also called aerosol transmission.

If aerosols had color, this is what they would look like. High-speed turbine handpieces or ultrasonic tooth-cleaning handpieces produce a large amount of water mist and droplet aerosols. The whole screen is pink.

However, the patient's droplets will not be so numerous, and they will not float in the air for a long time.

How to prevent aerosol transmission

First, all gatherings of people should be cancelled, and relatives and friends from key epidemic areas should be discouraged from visiting;

Second, open windows frequently to ventilate the room and keep the indoor air flowing;

Third, we must do a good job of daily household disinfection: wipe and disinfect key areas such as door handles, tables and chairs, and toilet seats with 75% alcohol or chlorine-containing disinfectant;

Fourth, pay attention to personal hygiene: wash your hands with running water, soap or hand sanitizer before and after meals, and cover your mouth and nose with a tissue or bent elbow when coughing or sneezing;

Fifth, avoid airborne and contact transmission: Family members should avoid contact with body secretions of those with suspicious symptoms, and do not share personal items; when dining, use serving chopsticks to share food, eat quickly, talk less, do not get too close to each other, avoid shaking hands and hugging, and smile and show etiquette;

Sixth, strictly implement home quarantine: outsiders must cooperate with relevant investigations, accurately report the facts, and actively accept quarantine; those who need home quarantine and observation should try to live in a separate residence from their family members. If conditions are limited, they should live in separate rooms and be isolated in single rooms. All family members living in the same room must wear masks;

7. Pay close attention to the health status of family members. If symptoms such as fever and cough occur, you should consciously avoid contact with others, wear a mask, go to the nearest fever clinic as soon as possible, and fully cooperate with treatment.