The panel and audience discuss issues relating to the value and politics of water - as part of the series of question-and-answer programmes in association with the Open University's Science in Context course.
Quentin Cooper and the expert panel discuss such questions as "How do we protect against mass natural water-poisoning from arsenic as happened in Bangladesh?" and "Will we run out of clean, fresh water in the future?" as well as "Who has the right to dam large rivers and alter the supply to those living downstream?" The fourth of six debates comes from Camden, London. Producer Fiona Roberts