Decidious trees loose the leafs in authum/winter and grow new in spring. When that is in your area I cannot tell, just look around you, what are the native trees doing right now?
If it is last years leafs you are worried about, dont be. Just let them drop. Collect and dispose just to be safe. If it is this years fresh leafs, then you might have a problem. But I doubt it. Way to early for most parts of northern hemisphere.