It does, smoke detectors sense a change in particle density in the air... not actually smoke.

If the filter gets dirty enough it'll go off. The detectors can't tell the difference between dust and smoke. I have to clean my filters every few years with air duster for this reason.

Oh no, that's most certainly possible. Dust blocks radiation just like smoke does, so it can set detectors off just fine.

I don't know why people are giving you the thumbs down. An excessive amount of dust actually is a fire risk, and if a fire starts there could be an explosion. That's why there have been devastating explosions in mills with lots of flour