I bet I could pin point exactly where they came from... Theres a derelict house on Greeves Street (No 25) and there are squatters living/dealing in it. Theres syringes everywhere down there....The house has a big above ground storm water channel running right down the side of it... When it rains hard it becomes a torrent.... Id say it would take less then 5 minutes for a syringe thrown in there to get washed to the beach.