English Abstract In the framework of BNS (policy notice regarding the
regulation of ionizing radiation) the maximum permissible lethal risk of 10
-6 a -1 for a single source of ionizing radiation is exceeded in the Dutch
population for exposures due to discharges of a thermal phosphorus plant,
the phosphate fertilizer industry and due to a consumerproduct (gasmantles
for lighting). Two kinds of "critical" groups are considered, one because
of geographical factors and an other because of special behaviour (diet
etc.). Both have a maximum risk for all sources of ionizing radiation of 5
to 6 x 10 -6. A combination of both factors could result in a maximum risk
of 8 x 10 -6. For about 98% of the Dutch population however the range in
risk estimate due to exposures to sources of radiation as considered in BNS
is from 0.3 to 1.5 x 10 -6 a -1.
