Extreme selenium and tellurium contamination in soils — An eighty year-old industrial legacy surrounding a Ni refinery in the Swansea Valley

Elevated levels of selenium (maximum 200 mg/kg) and tellurium (maximum 11 mg/kg) are reported in topsoils (< 5 cm) from around a long-established nickel refinery at Clydach in the Lower Swansea Valley, UK. Se and Te are correlated with each other and when these data are plotted as contour diagrams they show a concentric pattern centred on the refinery site. The origin of the Se and Te contamination is investigated. A review of the changes in the refinery practices at the site is presented and used to link the soil contamination to industrial pollution which took place over 80 years ago. The most recent air quality data available cannot rule out some Se contamination up to 2003.

► This paper describes extreme levels of the toxic elements Se and Te in topsoils. ► The levels described show a clear pattern with respect to an industrial source. ► The evidence supports a source for this contamination which dates from the 1930s or earlier. ► The paper demonstrates the longevity of Se and Te contamination in topsoils.