submicron airborne particle

例句：

1. 1. The particle size of thematerial is submicron.
   该材料的粒径为纳米级。
2. 2. Submicron particlesare difficult to detect with the naked eye.
   用肉眼难以检测到纳米级别的粒子。
3. 3.The submicron dust in the aircan cause respiratory problems.
   空气中的纳米级粉尘可能导致呼吸问题。