Radioactivity is all around us. On land there are radioactive isotopes in vegetation, soil and rocks. In the ocean some of the places they accumulate are the seafloor massive sulphides of hydrothermal vents, the polymetallic nodules of the deep abyssal plains, and the sediment of the ocean floor. Because radioactive isotopes are safely bound up in mineral structures, marine life has successfully adapted to the ocean’s natural background levels of radiation.

Deep sea mining would crush and fragment nodules and sulphide deposits, dispersing debris for extensive distances. The outer layers of nodules (most likely to be disrupted) are particularly enriched in radioactive alpha particles. These have form as extremely dangerous wrecking balls for cells, protein and DNA. They can build up in tissues of marine life, and similarly to mercury, can amplify their way up food chains that eventually reach our plates.

The report: Critical Questions about the Risks of Radiation Toxicity from Deep Sea Mining