Mattern FCM ,
Drost RMS ,
Glastra P ,
Ockhuizen A ,
English Abstract Sr-90-activities in Meuse, Rhine and Roer (about 3.5
Bq/m3) and Westerscheldt (9 Bq/m3) were nearly equal to those in 1988.
Activities in the Northsea (up to 17 Bq/m3) were slightly higher than in
1988 and are caused by discharges of nuclear reprocessing plants.
Sr-90-activities of the Westerscheldt depend on those of the Northsea.
Ra-226- activities in Rhine(4.2 Bq/m3), Roer(15 Bq/m3) and Westerscheldt
(38 Bq/m3) were higher than in 1988. That of the Meuse(3.3 Bq/m3) was
unchanged. The Ra-226 in Roer and Westerscheldt originate from discharges
by coalmines in the FRG respectively discharges of phosphogypsum. The
Westerscheldt transported in 1989 approximately 200 GBq Ra-226. In the
Westerscheldt and due to phosphogypsum, the activities of Pb-210 (16 Bq/m3)
and Po-210 (19 Bq/m3) were higher than in the Meuse, Rhine and Roer (2 to 5
Bq/m3). 20% to 85% of the activities were adsorbed on suspended matter.
Po-210-activities were higher than in 1988. In the Northsea, the activities
of Cs-134 (< 2 Bq/m3) and Cs-137(7 to 22 Bq/m3) were lower than in 1988.
Tritium-activities (1300 up to 2200 BQ/M3) were nearly the same as in