129I from the nuclear reprocessing facilities traced in precipitation and runoff in northern Europe.

A huge amount of radioactive 129I has been released into the environment from the nuclear energy industry, atomic weapon tests, and nuclear accidents. In this study, we present weekly and seasonal data on 129I measured in precipitation and runoff of northern Europe during 1998 and 1999. The 129I concentration is at 10(8)-10(9) atoms/L in precipitation and (2-5) x 10(8) atoms/L in runoff water, and it is 3-4 orders of magnitude higher than in the prenuclear era. Snow shows lower 129I concentration than rain, and there is apparently a positive correlation between surface air temperature and 129I. Precipitation chemistry, expressed as the content of Cl, SO4, and NO3 and atmospheric ozone, exhibits weak negative correlation with 129I values. Our 129I data on precipitation suggest significant influence of the northern European atmosphere by the discharges from the nuclear reprocessing facilities at Sellafield and La Hague.

Atmospheric interactions at northern high latitudes from weekly Be-isotopes in surface air.

We present weekly 7Be (from 1972 to 1995), and weekly/seasonal 10Be (for 1994) data in surface air from ground level stations in Sweden with a coverage of most of the northern high latitudes (56 degrees-68 degrees N). Our Be data are regionally representative and reveal seasonal variation and coupling with tropospheric air mass from middle-low latitudes. The Be data also suggests a few percent, and sometimes episodic, incursion of stratospheric air mass. Frequent precipitation depletes the Be isotopes in the air, but cyclone events contribute to enrichments. A strong coherence between the 7Be record and short-term (monthly-seasonal) change in solar activity is observed which introduces a new mechanism for driving the amplitude of seasonal variation.

Measurement of resuspended aerosol in the Chernobyl area. I. Discussion of instrumentation and estimation of measurement uncertainty.

Results of measurements of the resuspended radioactive aerosols in the Chernobyl area are presented which were obtained soon after the Chernobyl reactor accident and in a European project in 1992-1993. The measurements were carried out with the intention of obtaining a data base for dose assessment of resuspended radioactive particles. Potential significant dose contributions may result from inhalation and secondary contamination due to resuspended radionuclides. In this first article of a series of three papers, the instrumentation and the measurement uncertainties are discussed. An effort was made to sample quantitatively giant aerosol particles (particles larger than 10 microns aerodynamic diameter) as well. The comparison of the samplers shows, in general, an agreement of concentration measurements of 137Cs and 7Be within a factor of two. One sampler was identified with larger discrepancies and needs additional investigation of its sampling characteristics; for another device, the recalibration of the analysing system is recommended. Ordinary integrating samplers have a loss of about 30% in 137Cs activity compared to an isokinetic sampler collecting giant particles as well. The mean ratio of 137Cs activity concentration between an instrument sampling only particles larger than 10 microns and an ordinary integrating sampler is 0.39 +/- 0.15 during anthropogenic-enhanced resuspension. These findings demonstrate the significant contribution of giant particles to resuspended airborne radioactivity. The results of this study concerning integral measurements during wind-driven resuspension proved to be in good agreement with previously published data on resuspension.