The River Axe in Wookey Hole cave drains a large area of Central mendip. Three of the tributary streams enter St. Cuthbert’s Swallet after flowing through disturbed land, where lead mining was carried out from pre-Roman times until the early twentieth century (Gough 1967). Analyses of sediments collected from an excavation in the Fourth Chamber of Wookey Hole were compared with those from elsewhere, to permit an assessment to be made of the extent and magnitude of contamination by the former lead industry.