My parents always tell me if I should keep my door partially open as in "closed" but not locked into the frame.

However, my door has a line of space under it which would technically allow some degree of air flow.

My room is small, so dust accumulates pretty quickly. Would having the door open cause more dust to accumulate or less?

Does it really matter if I close my door or not for air flow when I sleep/am in it during the day? How much of a difference does it really make if the door is only partially open?

I’m asking this because I want to keep my door fully closed to reduce the amount of noise from outside my small room, but am wondering if it's worth doing so with airflow, dust accumulation, temperature, and O2/CO2 levels.