Bloomstein was brought up in a working class family in East London, and decided he wanted to become a documentary filmmaker after the influential Seven-Up. He trained at ATV and the BBC before becoming an independent filmmaker in 1970. Films such as his series Lifers and the 2003 follow-up Lifer - Living with Murder, talking to prisoners serving life sentences, and his latest film KZ, about the people living and working in the towns that used to house Nazi concentration camps, reveal the preoccupations in his work.