Although the data may be incomplete, the population dose due to occupationally exposed persons should not exceed 1% of the natural background radiation, even after allowing for an increased use of nuclear energy.
The radiation exposure of the majority of persons professionally engaged in handling radiation sources and radioactive substances is less than about 1 rem per year, or less than one fifth of the maximum permissible dose allowed for radiation exposure of the gonads. A number of countries have reported that the genetic dose to the whole population arising from the dose received by occupationally exposed persons, who constitute only a small fraction of the total population, is about 0.1 - 0.2 mrem per year.