Ceiling fans are great to have in the house, especially in warm summer months when you want the air circulated. They can also seem to be a magnet for all the dust in your house to get on the top of the blades, and if you have a dust allergy this means that dust gets flung around into the air every time you use the fan.
There is a trick you can do in order to prevent the dust from settling on your fan blades. All you need to do is use car wax, such as the hard car wax you use on your vehicle, and put that on the blades. Then the wax will prevent the blades from attracting the dust settling on the top of the blades.
It will need to be repeated in six months or so, depending on how often you use your ceiling fan. When you notice dust starting to sit on the blades again, just re-wax them.