I lived in West Oakland for 10 years. Not immediately adjacent to a freeway, but surrounded on 4 sides by a freeway within a half mile. All flat surfaces are ev

I lived in West Oakland for 10 years. Not immediately adjacent to a freeway, but surrounded on 4 sides by a freeway within a half mile. All flat surfaces are eventually are covered in black grit unless it rains. I assume it was not just tire dust but also diesel soot.