Measurement of radiocesium in Irish peatland soils

Results are presented for soils taken from twelve peatland sites in Ireland. Two depth horizons, 0–5 and 5–15 cm, were sampled on each site and sampling was carried out in summer and autumn. Deposition of Chernobyl¹³⁷Cs varied between 0.4 and 4.6 kBq m^–2, which is at the lower end of values reported by other authors for Irish agricultural soils. The data showed that the relative percentages of activity and deposition remained internally consistent in each soil horizon for Chernobyl and weapons fallout sources on both sampling occasions: this provided evidence that sampling and analytical procedures were consistent. An apparent reversal in the relative importance of weapons fallout in soils was found when deposition data were compared to the same data presented in activity format, and this same reversal was found for both soil horizons. Different conclusions may erroneously be drawn from data depending on the parameter by which we make measurements. Presentation of results should be carefully considered and depends on the purpose for which a study is intended. A statistically significant change in bulk density of the deeper soil horizon was found between summer and autumn. Changes in bulk density important to bear in mind that in addition to analytical errors, sampling methods can only provide estimations which themselves have inherent sources of error.