well I can't say that I have read the book you are talking about but I have read "Out of the Dust" by Karen Hesse and from what it said most of their crops we're destroyed due to the dust storms and as they prepare food sand enters the food that is why they put wet towels are out windows and doors to not allow much sand to answer and from what my history teacher said you have only like a few minutes to eat after food is prepared because if you wait longer for it to cool down sand would have already made its way to your food
-hope this helps
