Is it dust hitting the walls and falling to the edge of floor? Is it that your vacuum does not do a great job sucking the dirt from the edge of the floor? Is it the spinning of the earth and centrifugal force that causes the dirt to always be on the outside edges of the floor? Whatever the reason dirt and dust will always make its way to the edge of a carpet. If the edges of your carpet have the darkened effect this is dust build up that can be removed with a vacuum. Left untreated it will require a professional cleaning. A great carpet cleaner, like a barber, will make sure that even the edges the carpet are cleaned.
Remove the muck from your home, even in the most conspicuous areas. It will help you breathe better and give you a relaxed state of mind. Take note of the difference of coming home to an clean environment after a hard day’s work, or waking up to a clean home after a good night’s rest.