English Abstract During 1986 a reconnaissance survey was made of the
levels of Po-210 and other natural radionuclides in several Dutch water
bodies. Large differences in the activity levels of water and suspended
matter were found between these waters. A subdivision of the observed
levels was made into "low", "probably increased" and "clearly increased".
Levels in the Eastern Scheldt are low. Clearly increased levels are found
in the Rhine downstream of Rotterdam, the mouth of the Scheldt and locally
at IJmuiden. These increases can be linked to emissions from phosphorous
and steel producing industries. The transport of the radionuclides from the
Scheldt through the Western Scheldt and the North Sea could be traced.
Further transport in the North Sea from the Western Scheldt and the Rhine
was not clearly distinguishable. For this and for insight in the balance
between industrial emissions of natural radionuclides and their further
distribution and/or accumulation additional information and research needs
have been indicated.