The road crew has chipped roadside saplings and such, they leave them on the banks. Here nobody wants these little piles so I think it’s be okay to gather them up, but I’d have to look for aged ones, not fresh. Otherwise, there isn’t a crew nearby of the actual tree trimmers for the power company (and then it needs a year to age and dry out). I’ve had that in past years, and aged the pile before using. Do you think pine needles are low dust? There are larch trees that every fall drop their needles on to the road, easy to rake up.