The Greenland ice sheet is often pictured as one of the last remaining untouched wildernesses of the world. But even remote parts of the ice are rich in toxins released by human activity, a new study finds.

Banned chemicals, mercury and lead are present in the Greenland ice sheet at concentrations high enough for microbes specialising in breaking them down to be found there, according to the study published in Environmental Research Letters.

These pollutants – including polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) – are mostly not from local sources. Persistent organic pollutants travel wid