I recently moved into a renovated apartment building that was sandblasted, which I was told by maintenance. There are black particles falling from in between the beams on my window sills and floors in the living room. When it is windy out it gets worse. Maintenance filled in the areas around the beams but is this hazardous to my families health?? We have been here since last July and have been told by the owners that it is okay, IS IT???