I didn't realise it was used so widely. I just read this about the brushes - http://www.amateurphotographer.co.uk/photo-news/538049/polonium-210-present-in-dark

I didn't realise it was used so widely. I just read this about the brushes - http://www.amateurphotographer.co.uk/photo-news/538049/polonium-210-present-in-darkroom-gadget http://www.amateurphotographer.co.uk/photo-news/538049/polon...