Nope. I can't imagine any possible health risk, besides slivers. Treated lumber, or at least older treated lumber (not sure about newer stuff), has kind of a greenish tint to it. This is from the chemicals that are soaked into the wood under high pressure, and then allowed to dry under this pressure. I can assure you that popsicle companies wouldn't dare use treated lumber for their sticks, since these chemicals would surely leak out into the water of the popsical. This would make Arsenic-flavored popsicles, and those dont sound too tasty.