Hydrogen sulphide is the smell that comes from a rotten egg. Imagine that seeping out from a mound of rubbish the size of a small hill.You don't have to imagine it if you go to the Staffordshire town of Silverdale, population 5,700. It's an ever-present threat and a frequent reality. On this week's ClimateCast, Tom Heap visits Silverdale to speak to residents campaigning to shut down a landfill that's been haunting them for years.He talks to protesters in the village, as well as the local doctors' surgery to ask health professionals if they believe the landfill is a risk to health - which operators deny.Producers: Emma Rae Woodhouse and Mickey CarrollEditors: Luke Denne and Philly Beaumont