○「閉空間に漂うエアロゾル粒子を追い出すには空気の流れと換気・空気清浄機が必要です!」
ガス分子は混ざりやすい（拡散しやすい）ですが、エアロゾル粒子の中でも大きさが1,000分の１mm（１μm）程度の微小なエアロゾル粒子は、室内空間中ではガス分子に比べればほとんど拡散しません。さらに、目に見える粒子とは異なり，その沈降速度も非常に小さく、室内では浮いたまま漂っています。微小なエアロゾル粒子を室内から追い出すには、空気の流れ（気流）により移動させ、室外への排出（換気）または空気清浄機などにより除去することが必要です。
→ ［見解（全文）はPDFをご覧下さい］（2020.3.18）
Removing Aerosol Particles from Enclosed Spaces Requires Airflow, Ventilation, and Air Purifiers
While gas molecules tend to mix and diffuse easily in the air, aerosol particles behave quite differently—especially those that are extremely small, around 1 micrometer (1 μm) in diameter. These fine aerosol particles do not disperse as readily as gases in indoor environments. Unlike visible particles, they also have an extremely low settling velocity, meaning they can remain suspended in the air for extended periods.
To effectively remove these tiny aerosol particles from enclosed spaces, it is essential to create airflow that can transport them out of the room. This can be achieved through proper ventilation—bringing in fresh air and expelling indoor air—or by using air purifiers that capture and eliminate airborne particles.
Without sufficient airflow or filtration, these particles can linger in the air, potentially increasing the risk of airborne transmission of contaminants. Therefore, maintaining good indoor air quality through ventilation and purification is a key strategy in managing aerosol exposure.
👉 [See PDF (in Japanese) to read the full statement] (Published: March 18, 2020)
indoor_aerosol_20200318