Scientists find toxic element in shale region

A study by a team from the university and published in the journal Applied Geochemistry has revealed high levels of selenium in rock samples from the Bowland Shale. Picture: TSPL

SCIENTISTS from the University of Aberdeen have discovered high levels of a toxic element in rock samples taken from an area of the UK targeted for shale gas extraction.

A study by a team from the university’s School of Geosciences and published in the journal Applied Geochemistry has revealed high levels of selenium in rock samples from the Bowland Shale, a geological formation in the north of England rich in resources of shale gas.

The scientists say that excessive levels of selenium are known to pose a risk to human health, and so care must be taken during extraction to avoid high levels of the element being released into groundwater during drilling or ‘fracking’ operations.

Professor John Parnell, who led the study, said: “A major factor to be considered during shale gas drilling is the accompanying water, which may contain chemicals that require careful treatment.

“The samples we have analysed from the Bowland Shale are some of the most selenium-rich in the British Isles”.

Noting that some were above far stricter European Union limits, Parnell said that “it is clear that any drilling to extract shale gas in the Bowland Shale area must be carefully managed”.

However, he added that selenium “is a rare element for which demand is likely to increase, so there is a commercial incentive here which companies will no doubt be mindful of”.