Showering in Dust

I spent half an hour this afternoon cleaning twenty years of dust out from under my Mother's refrigerator.

She's hosting our family holiday dinner this year. (My youngest niece is doing most of the food preparation.) When she mentioned all the cleaning she was doing I innocently asked if she had cleaned the heat exchanger under the refrigerator yet.

She said "Why would I do that?" (I should have suspected this when I learned - during the replacement of her water heater - that she had never flushed her old one.)

I used the sweeper on inhale with a crevice tool, then used her wand duster and got as much as I could. Then I switched the sweeper to exhale. A fountain of dust blew up the back of the refrigerator and showered down on me and much of the kitchen.