Worried about laburnum

Hello A week ago I sited a bird bath close to a laburnum tree and the odd seed pod or leaf has fallen into it. Concerned about the poisonous nature of laburnum seeds I have been fishing them out daily and have cut back one over-hanging branch. The bird bath is small and so not much water in it so anything leaching into it might be quite concentrated. My question is, can a seed pod or leaf leach poison into the water? I've only seen one female house sparrow use it so far - it's in the front garden so in a busy location - and it gave me such pleasure to watch her tentatively drink and bathe, but now I feel guilty that I may have set up a death trap. Can anyone help me with this? Thank you.