Update on the Radioactivity of Manganese Nodules

In a new study published on September 4, 2025, the Federal Institute for Geosciences and Natural Resources, in collaboration with external experts, scientifically and from a radiation protection perspective, accurately assessed the actual risks posed by the natural radioactivity of manganese nodules.

A study published in May 2023 had pointed out that exposure limits set by the Radiation Protection Ordinance had been exceeded and warned of potential health risks associated with handling manganese nodules. A new study, published in the journal  Scientific Reports  with the participation of the BGR, clarifies that, according to the Radiation Protection Act, the effective body dose under realistic working conditions is decisive for assessing the actual risks posed by natural radionuclides in manganese nodules. The investigations—in which the BGR collaborated with the expert organizations IAF-Radioökologie GmbH and Nuclear Control & Consulting GmbH, as well as the Federal Office for Radiation Protection (BfS)—show that, in principle, there are no health risks associated with activities involving manganese nodules, whether in laboratory research or in future industrial deep-sea mining operations.

The BGR’s press release provides direct access to the two peer-reviewed publications and the two reports (each available in German and English).

The KDM Strategy Group on Marine Mineral Resources had published a statement in September 2023 in response to the first study.