engleski

Radiostrontium activity concentrations in milk in the Republic of Croatia for 1961 - 2001 and dose assessment

Results of systematic measurements of 90Sr activity concentrations in milk for the period 1961 - 2001 are summarized. An exponential decline of radioactivity followed the moratorium on atmospheric nuclear testing. The highest activity of 90Sr deposited by fallout, being 1060 Bq m-2, was recorded in 1963, while the peak 90Sr activity concentration in milk, 1.42 ? 0.17 Bq L-1, was recorded in 1964. The values in year 2001 for fallout deposition and milk were 7.7 Bq m-2 and 0.07 ? 0.03 Bq L-1, respectively. The reactor accident at Chernobyl caused higher 90Sr levels only in 1986. 90Sr fallout activity affects milk activity, the coefficient of correlation between 90Sr fallout activity and 90Sr activity concentrations in milk being 0.80. The transfer coefficient from fallout deposition to milk was estimated to be 2.5 × 10-3 Bq y L-1 / (Bq m-2). The dose incurred by milk consumption was estimated for the Croatian population, the annual collective effective dose in 2001 being approximately 2.0 person-Sv.

milk; 90Sr; contamination; environmental; fallout

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