Yeah disposal of them is fucked. A mate told me when he lived in some sydney suburb, a near by walking path that was closed off and unmaintained, there is a creek that gets dry every so often, and when it does all yo0u can see is thousands and thousands of needles and rubbish everywhere. We normally keep our boxes till they build up to around 10 or more, then put them in paper bags inside plastic bags, and put them in the trash the night before bin day up the road, where a public trashbin is. But there should be bins next to vending machines.