why do large collections of dust accumulate on frequently used fans?

I use the fan in my room nightly yet it has more dust on it than any other surface, how does this occur?
Fans pull in dust particles from the air [1, 3, 4]. The leading edge of the fan blade develops the most charge due to frictional forces and thus pulls in the most dust [1]. Dust also collects on the blades due to static electricity and fluid dynamics [2].
Dust tends to accumulate on ceiling fans for the following reasons: first, plastic fan blades accumulate dust because they rotate, causing a static electrical charge to build up on their leading edges [1, 2, 3]. The charged dust particles then stick to the charged areas of the blades [4]. Second, metal fans accumulate dust because of airflow and fluid dynamics [2]