The Ribble estuary near Preston receives radioactive substances from liquid effluent, discharged directly from the nearby Springfields Fuels Ltd site, and also transported down the coast from the Sellafield Ltd site via the Irish Sea. Estuaries are complex environments, influenced by both the marine tidal processes and the freshwater input from rivers. Some of the radioactive substances eventually become deposited in sediment in the estuary and on the nearby salt marsh.
This project studies the factors that influence the external dose a person may receive from beta and gamma radiation from Ribble sediments. the work looks at the conditions which may change the dose received including: the effects of high and low, spring and neap tides; whether boat hulls or clothing materials provide shielding from the radioactivity in the sediment; the effect of the position of boats relative to the banks; and the different habits of people using the estuary, for example wildfowlers laying flat on the sediment, or anglers sitting next to a channel filled with water.