Long abandoned metal mines are having a huge impact on rivers across the UK. BBC Inside Science reporter Patrick Hughes visits Cwmystwyth in Wales, where he finds lead, zinc and cadmium seeping into waterways. It’s the costly legacy left after hundreds of years of mining. Roma Agrawal breaks down our modern world into seven essential basic inventions in her book Nuts and Bolts which has been shortlisted for the Royal Society Science Book Prize. She talks to Marnie about the surprising history behind some of these inventions.  And, as a cryogenic tank of bull semen is stolen from a farm in County Tyrone in Northern Ireland, it got us thinking: how can selective breeding help reduce carbon and methane emissions from cattle? Professor Eileen Wall from Scotland’s Rural College tells us more. Presenter:  Marnie Chesterton Producers: Harrison Lewis, Hannah Robins and Patrick Hughes Editor: Richard Collings Production Co-ordinator: Jana Bennett-Holesworth BBC Inside Science is produced in Cardiff by BBC Wales and West in collaboration with the Open University.