[en] For natural radiation, occupational radiation protection in workplaces involves the protection of workers against enhanced exposures due to cosmic and terrestrial radiation, the latter due to human activities. Enhancement is measured against an uncertain level of background radiation at an estimated average global per caput dose of 2.4 mSv·a^-1. For cosmic radiation, enhanced exposures mainly arise from flying in aircraft. For occasional and frequent flyers this generally measures below 1 mSv·a^-1. For aircrew, doses within the range 2.5-4.0 mSv·a^-1 are, however, reported. Enhanced terrestrial radiation is mainly associated with mining and minerals processing operations. For mining, ore processing and physical separation process facilities, ²³⁸U or ²³²Th concentrations within the range 1-14 Bq·g^-1 could typically result in an external radiation or dust inhalation dose of 1 mSv·a^-1 (2000 h). For chemical extraction and metal melting plants the relation is more variable. Values within the range of 0.1-10 000 Bq·g^-1 have been reported for various industries. Regulatory aspects for occupational exposure to natural radiation are briefly introduced. Some of the more pronounced differences between occupational exposure due to naturally occurring radioactive material and that due to the nuclear industry are briefly indicated, with some of the remaining problem areas discussed. (author)