Iodine in the soils of North Derbyshire

Derbyshire was one of the best known centres of endemic goitre in Great Britain. Some 160 km from the coast in the direction of the prevailing wind, topsoils in the area are generally low in iodine (mean = 5.44 mg l/kg). Weathered rocks and soils are richer in iodine than the unweathered bedrocks, with soils developed over limestones being richer than those over sandstones, shales and dolomites. Highest iodine contents in soil profiles over limestones occur in the upper horizons while over sandstones, iodine concentrates in the lower horizons. The major cause of endemic goitre in north Derbyshire is likely to be relatively low levels of iodine, while the calcium rich soils of the area may contribute by reducing plant iodine uptake.