To maintain safe air quality in a shelter, you must focus on creating a controlled environment that prevents outside air from entering. The primary goal is to prevent the infiltration of radioactive dust and aerosols. If you are using mechanical ventilation, ensure it is equipped with high efficiency particulate air (HEPA) filters, which are designed to trap extremely small particles.
One essential measure is the practice of sealing all entry points. This includes using heavy duty plastic sheeting and duct tape to seal windows, doors, and vents that are not part of your filtered air supply. If you are in a building with a central HVAC system, turn the system off immediately to prevent it from drawing contaminated air from the outside into your protected space.
If you must ventilate for fresh air, use a positive pressure system if possible. This involves pumping filtered air into the room so that the internal pressure is higher than the outside, which pushes air out through cracks rather than allowing outside air to leak in. Regularly monitor the air quality and change filters according to manufacturer instructions to ensure maximum protection against fine particulates.
