Time trends (1986–2003) of radiocesium transfer to roe deer and wild boar in two Austrian forest regions

Starting shortly after the Chernobyl accident, samples of roe deer and wild boar from two comparatively highly contaminated Austrian forest stands have been regularly analysed for 137Cs. Until 1995 average 137Cs concentrations exceeded 1000 Bq kg−1 in both roe deer and wild boar. Long-term and seasonal trends are similar in both investigation sites. While 137Cs aggregated transfer factor (Tag) values show a significant decreasing trend in roe deer (ecological half-time 8.6 and 7.2 years, respectively), Tag-values in wild boar are highly variable, but rather increasing values are observed over the last years. Tag-values for roe deer are between 0.04 and 0.008 m2 kg−1 fresh weight (1987–2003); values for wild boar are between 0.008 m2 kg−1 (1988) and 0.046 m2 kg−1 (1996) fresh weight. Seasonal trends for both species are in good agreement with observations from German forests: increased mushroom ingestion leads to higher 137Cs Tag-values for roe deer in the second half of the year (August–December) compared to the first half (January–July). Tag-values for wild boar are highest in the first half of the year.