How long were the leaves there before you raked them up? How much traffic passed by?
The longer the leaves were there, and the more traffic there was, the greater the chance they would have picked up some oil and rubber from that traffic, but if a few days are probably even a couple of weeks there would not be enough to be concerned about. Six months, a year, maybe so.

I once to a new neighborhood once where I put out door hangers offering to remove leaves and owner made check payable to the local fire fighters fund. Them folks loved their fire fighters and I had more leaves than I could geather. I contacted a couple of community activists that expanded the plan so all was well in the end. So caveat,be carful what you wish for because you might get it.

In my professional opinion there is nothing to worry about here. When there are no leaves, how much oil is running around in the street? None, I'll wager. Maybe a few spots from parked cars. Leaves laying in the street for a few days (or even weeks) could not possibly pick up enough to be a problem.

Motor oil, while not a healthy food, is less toxic than lighter petroleum products (diesel and gasoline). Hydrocarbons are somewhat biodegradable anyway, so the minute traces that were there are even more minute after composting.

Actually, there is probably more airborne deposition of pollutants from car exhaust all over your yard throughout the year, than what could be found in fall leaves. If the one isn't a problem, the other shouldn't be.

I'd have no concerns with using these leaves.

Lloyd

So, Tox, what is that sheen I see on the water that accumulates on roads after a rain? What are those little black specks found on a white filter paper when that water is run through? Why does rainwater collected from roads sometimes burn?

So, Tox, what is that sheen I see on the water that accumulates on roads after a rain? ( shineola?) What are those little black specks found on a white filter paper when that water is run through? ( fly specks ?) Why does rainwater collected from roads sometimes burn? ( IDK but maybe the key to our energy shortage ).