A new publication from WP2 authors H. Haanes, S. Dahlgren and A. L. Rudjord from Norway explored pathways during the cold season of 222Rn, 220Rn and thoron progeny within the legacy iron mines and in the niobium legacy mine in the Fen igneous complex in Norway. From the performed measurements, authors assume a cold season dose of around 17 – 24 µSv / h, which would be relevant information for the new mining activities planned in the Fen complex. These mines are mainly chimney ventilated and large differences in exposure can be expected between seasons at different locations within these mines. In the winter season, mine air is expelled through mine openings in the upper part of the mines, carrying with it radioactive particles from within the mines and affecting the surrounding area. In summer the ventilation pattern is opposite, with mine air colder than surroundings ventilating through mine openings at the bottom of the mine system. Click here to read the publication in full. A full list of RadoNorm publications is available on our website.