New regulations on radiation in buildings. Nya bestammelser om stralning i byggnader.

Tests carried out during the sixties and seventies showed that there was a correlation between lung cancer and the existence of radon gas in mines and that there was radon gas in homes built of aerated concrete based on slate. This led to political activity with regulations for limits on emanation in new, re-built and existing buildings. Provisions were also made for grants to help house owners finance the improvements specified.< In the new bye-laws, SBN 80, gamma radiation is not to exceed 50 mu.R/h, the radon content is not to exceed an annual mean of 70 Bq/cu.m. and the gamma and radium index is not to exceed 200 Bq/cu.m. in new buildings. If rebuilding the annual mean radon content is not to exceed 200 Bq/cu.m. indoors.